fix: add Google Chat to list of alert types when determining valid providers (#341)

Relevant: #336

.examples/docker-compose-grafana-prometheus/README.md

@@ -0,0 +1,41 @@
+## Usage
+Gatus exposes Prometheus metrics at `/metrics` if the `metrics` configuration option is set to `true`.
+
+To run this example, all you need to do is execute the following command:
+```console
+docker-compose up
+```
+Once you've done the above, you should be able to access the Grafana dashboard at `http://localhost:3000`.
+
+![Gatus Grafana dashboard](../../.github/assets/grafana-dashboard.png)
+
+
+## Queries
+By default, this example has a Grafana dashboard with some panels, but for the sake of verbosity, you'll find
+a list of simple queries below. Those make use of the `key` parameter, which is a concatenation of the endpoint's
+group and name.
+
+### Success rate
+```
+sum(rate(gatus_results_total{success="true"}[30s])) by (key) / sum(rate(gatus_results_total[30s])) by (key)
+```
+
+### Response time
+```
+gatus_results_duration_seconds
+```
+
+### Total results per minute
+```
+sum(rate(gatus_results_total[5m])*60) by (key)
+```
+
+### Total successful results per minute
+```
+sum(rate(gatus_results_total{success="true"}[5m])*60) by (key)
+```
+
+### Total unsuccessful results per minute
+```
+sum(rate(gatus_results_total{success="false"}[5m])*60) by (key)
+```

.examples/docker-compose-grafana-prometheus/config/config.yaml

@@ -2,15 +2,18 @@ metrics: true
 endpoints:
   - name: website
     url: https://twin.sh/health
-    interval: 30s
+    interval: 5m
     conditions:
       - "[STATUS] == 200"
+
+  - name: example
+    url: https://example.com/
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+
   - name: github
     url: https://api.github.com/healthz
     interval: 5m
     conditions:
       - "[STATUS] == 200"
-  - name: example
-    url: https://example.com/
-    conditions:
-      - "[STATUS] == 200"

.examples/docker-compose-grafana-prometheus/docker-compose.yml

@@ -7,7 +7,7 @@ services:
     ports:
       - "8080:8080"
     volumes:
-      - ./config.yaml:/config/config.yaml
+      - ./config:/config
     networks:
       - metrics
 

.examples/docker-compose-grafana-prometheus/grafana/provisioning/dashboards/gatus.json

@@ -0,0 +1,582 @@
+{
+  "annotations": {
+    "list": [
+      {
+        "builtIn": 1,
+        "datasource": "-- Grafana --",
+        "enable": true,
+        "hide": true,
+        "iconColor": "rgba(0, 211, 255, 1)",
+        "name": "Annotations & Alerts",
+        "type": "dashboard"
+      }
+    ]
+  },
+  "editable": true,
+  "gnetId": null,
+  "graphTooltip": 0,
+  "id": 3,
+  "links": [],
+  "panels": [
+    {
+      "cacheTimeout": null,
+      "datasource": null,
+      "description": "Number of successful results compared to the total number of results during the current interval",
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 0
+      },
+      "id": 9,
+      "links": [],
+      "options": {
+        "fieldOptions": {
+          "calcs": [
+            "mean"
+          ],
+          "defaults": {
+            "mappings": [
+              {
+                "id": 0,
+                "op": "=",
+                "text": "N/A",
+                "type": 1,
+                "value": "null"
+              }
+            ],
+            "max": 1,
+            "min": 0,
+            "nullValueMode": "connected",
+            "thresholds": [
+              {
+                "color": "red",
+                "value": null
+              },
+              {
+                "color": "semi-dark-orange",
+                "value": 0.6
+              },
+              {
+                "color": "yellow",
+                "value": 0.8
+              },
+              {
+                "color": "dark-green",
+                "value": 0.95
+              }
+            ],
+            "unit": "percentunit"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "horizontal",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": false
+      },
+      "pluginVersion": "6.4.4",
+      "targets": [
+        {
+          "expr": "sum(rate(gatus_results_total{success=\"true\"}[30s])) by (key) / sum(rate(gatus_results_total[30s])) by (key)",
+          "hide": false,
+          "legendFormat": "{{key}}",
+          "refId": "B"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Success rate",
+      "type": "gauge"
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "cacheTimeout": null,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 0
+      },
+      "id": 11,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "null as zero",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pluginVersion": "6.4.4",
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "gatus_results_duration_seconds",
+          "format": "time_series",
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "{{key}}",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Response time",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "cacheTimeout": null,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 8
+      },
+      "id": 10,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "links": [],
+      "nullPointMode": "connected",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pluginVersion": "6.4.4",
+      "pointradius": 2,
+      "points": true,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(rate(gatus_results_total{success=\"true\"}[30s])) by (key) / sum(rate(gatus_results_total[30s])) by (key)",
+          "format": "time_series",
+          "instant": false,
+          "interval": "",
+          "intervalFactor": 1,
+          "legendFormat": "{{key}}",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Success rate",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "description": "Number of results per minute",
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 8
+      },
+      "id": 2,
+      "interval": "",
+      "legend": {
+        "alignAsTable": false,
+        "avg": false,
+        "current": false,
+        "hideEmpty": false,
+        "hideZero": false,
+        "max": false,
+        "min": false,
+        "rightSide": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "nullPointMode": "null",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(rate(gatus_results_total[5m])*60) by (key)",
+          "format": "time_series",
+          "hide": false,
+          "instant": false,
+          "interval": "30s",
+          "intervalFactor": 1,
+          "legendFormat": "{{key}}",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Total results per minute",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "decimals": null,
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 12,
+        "x": 0,
+        "y": 16
+      },
+      "id": 5,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "nullPointMode": "null",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(rate(gatus_results_total{success=\"true\"}[5m])*60) by (key)",
+          "instant": false,
+          "interval": "30s",
+          "legendFormat": "{{key}}",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Successful results per minute",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "decimals": null,
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    },
+    {
+      "aliasColors": {},
+      "bars": false,
+      "dashLength": 10,
+      "dashes": false,
+      "datasource": null,
+      "fill": 1,
+      "fillGradient": 0,
+      "gridPos": {
+        "h": 7,
+        "w": 12,
+        "x": 12,
+        "y": 16
+      },
+      "id": 3,
+      "legend": {
+        "avg": false,
+        "current": false,
+        "max": false,
+        "min": false,
+        "show": true,
+        "total": false,
+        "values": false
+      },
+      "lines": true,
+      "linewidth": 1,
+      "nullPointMode": "null",
+      "options": {
+        "dataLinks": []
+      },
+      "percentage": false,
+      "pointradius": 2,
+      "points": false,
+      "renderer": "flot",
+      "seriesOverrides": [],
+      "spaceLength": 10,
+      "stack": false,
+      "steppedLine": false,
+      "targets": [
+        {
+          "expr": "sum(rate(gatus_results_total{success=\"false\"}[5m])*60) by (key)",
+          "interval": "30s",
+          "legendFormat": "{{key}} ",
+          "refId": "A"
+        }
+      ],
+      "thresholds": [],
+      "timeFrom": null,
+      "timeRegions": [],
+      "timeShift": null,
+      "title": "Unsuccessful results per minute",
+      "tooltip": {
+        "shared": true,
+        "sort": 0,
+        "value_type": "individual"
+      },
+      "type": "graph",
+      "xaxis": {
+        "buckets": null,
+        "mode": "time",
+        "name": null,
+        "show": true,
+        "values": []
+      },
+      "yaxes": [
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        },
+        {
+          "format": "short",
+          "label": null,
+          "logBase": 1,
+          "max": null,
+          "min": null,
+          "show": true
+        }
+      ],
+      "yaxis": {
+        "align": false,
+        "alignLevel": null
+      }
+    }
+  ],
+  "refresh": "1m",
+  "schemaVersion": 20,
+  "style": "dark",
+  "tags": [],
+  "templating": {
+    "list": []
+  },
+  "time": {
+    "from": "now-1h",
+    "to": "now"
+  },
+  "timepicker": {
+    "refresh_intervals": [
+      "5s",
+      "10s",
+      "30s",
+      "1m",
+      "5m",
+      "15m",
+      "30m",
+      "1h",
+      "2h",
+      "1d"
+    ]
+  },
+  "timezone": "",
+  "title": "Gatus",
+  "uid": "KPI7Qj1Wk",
+  "version": 2
+}

.examples/docker-compose-grafana-prometheus/grafana/provisioning/dashboards/main.json

@@ -1,300 +0,0 @@
-{
-  "annotations": {
-    "list": [
-      {
-        "builtIn": 1,
-        "datasource": "-- Grafana --",
-        "enable": true,
-        "hide": true,
-        "iconColor": "rgba(0, 211, 255, 1)",
-        "name": "Annotations & Alerts",
-        "type": "dashboard"
-      }
-    ]
-  },
-  "editable": true,
-  "gnetId": null,
-  "graphTooltip": 0,
-  "id": 2,
-  "links": [],
-  "panels": [
-    {
-      "aliasColors": {},
-      "bars": false,
-      "dashLength": 10,
-      "dashes": false,
-      "datasource": null,
-      "fill": 1,
-      "fillGradient": 0,
-      "gridPos": {
-        "h": 14,
-        "w": 12,
-        "x": 0,
-        "y": 0
-      },
-      "id": 2,
-      "legend": {
-        "avg": false,
-        "current": false,
-        "max": false,
-        "min": false,
-        "show": true,
-        "total": false,
-        "values": false
-      },
-      "lines": true,
-      "linewidth": 1,
-      "nullPointMode": "null",
-      "options": {
-        "dataLinks": []
-      },
-      "percentage": false,
-      "pointradius": 2,
-      "points": false,
-      "renderer": "flot",
-      "seriesOverrides": [],
-      "spaceLength": 10,
-      "stack": false,
-      "steppedLine": false,
-      "targets": [
-        {
-          "expr": "sum(rate(gatus_tasks[30s])) by (endpoint)",
-          "interval": "30s",
-          "legendFormat": "{{endpoint}}",
-          "refId": "A"
-        }
-      ],
-      "thresholds": [],
-      "timeFrom": null,
-      "timeRegions": [],
-      "timeShift": null,
-      "title": "All tasks executed over time",
-      "tooltip": {
-        "shared": true,
-        "sort": 0,
-        "value_type": "individual"
-      },
-      "type": "graph",
-      "xaxis": {
-        "buckets": null,
-        "mode": "time",
-        "name": null,
-        "show": true,
-        "values": []
-      },
-      "yaxes": [
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        },
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        }
-      ],
-      "yaxis": {
-        "align": false,
-        "alignLevel": null
-      }
-    },
-    {
-      "aliasColors": {},
-      "bars": false,
-      "dashLength": 10,
-      "dashes": false,
-      "datasource": null,
-      "fill": 1,
-      "fillGradient": 0,
-      "gridPos": {
-        "h": 7,
-        "w": 12,
-        "x": 12,
-        "y": 0
-      },
-      "id": 3,
-      "legend": {
-        "avg": false,
-        "current": false,
-        "max": false,
-        "min": false,
-        "show": true,
-        "total": false,
-        "values": false
-      },
-      "lines": true,
-      "linewidth": 1,
-      "nullPointMode": "null",
-      "options": {
-        "dataLinks": []
-      },
-      "percentage": false,
-      "pointradius": 2,
-      "points": false,
-      "renderer": "flot",
-      "seriesOverrides": [],
-      "spaceLength": 10,
-      "stack": false,
-      "steppedLine": false,
-      "targets": [
-        {
-          "expr": "sum(rate(gatus_tasks{success=\"false\"}[30s])) by (endpoint)",
-          "interval": "30s",
-          "legendFormat": "{{endpoint}}",
-          "refId": "A"
-        }
-      ],
-      "thresholds": [],
-      "timeFrom": null,
-      "timeRegions": [],
-      "timeShift": null,
-      "title": "Unsuccessful tasks",
-      "tooltip": {
-        "shared": true,
-        "sort": 0,
-        "value_type": "individual"
-      },
-      "type": "graph",
-      "xaxis": {
-        "buckets": null,
-        "mode": "time",
-        "name": null,
-        "show": true,
-        "values": []
-      },
-      "yaxes": [
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        },
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        }
-      ],
-      "yaxis": {
-        "align": false,
-        "alignLevel": null
-      }
-    },
-    {
-      "aliasColors": {},
-      "bars": false,
-      "dashLength": 10,
-      "dashes": false,
-      "datasource": null,
-      "fill": 1,
-      "fillGradient": 0,
-      "gridPos": {
-        "h": 7,
-        "w": 12,
-        "x": 12,
-        "y": 7
-      },
-      "id": 5,
-      "legend": {
-        "avg": false,
-        "current": false,
-        "max": false,
-        "min": false,
-        "show": true,
-        "total": false,
-        "values": false
-      },
-      "lines": true,
-      "linewidth": 1,
-      "nullPointMode": "null",
-      "options": {
-        "dataLinks": []
-      },
-      "percentage": false,
-      "pointradius": 2,
-      "points": false,
-      "renderer": "flot",
-      "seriesOverrides": [],
-      "spaceLength": 10,
-      "stack": false,
-      "steppedLine": false,
-      "targets": [
-        {
-          "expr": "sum(rate(gatus_tasks{success=\"true\"}[30s])) by (endpoint)",
-          "instant": false,
-          "interval": "30s",
-          "legendFormat": "{{endpoint}}",
-          "refId": "A"
-        }
-      ],
-      "thresholds": [],
-      "timeFrom": null,
-      "timeRegions": [],
-      "timeShift": null,
-      "title": "Successful tasks",
-      "tooltip": {
-        "shared": true,
-        "sort": 0,
-        "value_type": "individual"
-      },
-      "type": "graph",
-      "xaxis": {
-        "buckets": null,
-        "mode": "time",
-        "name": null,
-        "show": true,
-        "values": []
-      },
-      "yaxes": [
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        },
-        {
-          "format": "short",
-          "label": null,
-          "logBase": 1,
-          "max": null,
-          "min": null,
-          "show": true
-        }
-      ],
-      "yaxis": {
-        "align": false,
-        "alignLevel": null
-      }
-    }
-  ],
-  "refresh": "10s",
-  "schemaVersion": 20,
-  "style": "dark",
-  "tags": [],
-  "templating": {
-    "list": []
-  },
-  "time": {
-    "from": "now-30m",
-    "to": "now"
-  },
-  "timepicker": {},
-  "timezone": "",
-  "title": "Gatus",
-  "uid": "KPI7Qj1Wk",
-  "version": 3
-}

.examples/docker-compose-mattermost/docker-compose.yml

@@ -6,7 +6,7 @@ services:
     ports:
       - "8080:8080"
     volumes:
-      - ./config.yaml:/config/config.yaml
+      - ./config:/config
     networks:
       - default
 

.examples/docker-compose-postgres-storage/config/config.yaml

@@ -26,7 +26,7 @@ endpoints:
       - "[STATUS] == 200"
 
   - name: example-dns-query
-    url: "8.8.8.8" # Address of the DNS server to use
+    url: "1.1.1.1" # Address of the DNS server to use
     interval: 5m
     dns:
       query-name: "example.com"

.examples/docker-compose-postgres-storage/docker-compose.yml

@@ -19,7 +19,7 @@ services:
     ports:
       - "8080:8080"
     volumes:
-      - ./config.yaml:/config/config.yaml
+      - ./config:/config
     networks:
       - web
     depends_on:

.examples/docker-compose-sqlite-storage/config/config.yaml

@@ -26,7 +26,7 @@ endpoints:
       - "[STATUS] == 200"
 
   - name: example-dns-query
-    url: "8.8.8.8" # Address of the DNS server to use
+    url: "1.1.1.1" # Address of the DNS server to use
     interval: 5m
     dns:
       query-name: "example.com"

.examples/docker-compose-sqlite-storage/docker-compose.yml

@@ -5,5 +5,5 @@ services:
     ports:
       - "8080:8080"
     volumes:
-      - ./config.yaml:/config/config.yaml
+      - ./config:/config
       - ./data:/data/

.examples/docker-compose/docker-compose.yml

@@ -5,4 +5,4 @@ services:
     ports:
       - 8080:8080
     volumes:
-      - ./config.yaml:/config/config.yaml
+      - ./config:/config

.examples/kubernetes/gatus.yaml

@@ -54,10 +54,10 @@ spec:
       app: gatus
   template:
     metadata:
-      labels:
-        app: gatus
       name: gatus
       namespace: kube-system
+      labels:
+        app: gatus
     spec:
       serviceAccountName: gatus
       terminationGracePeriodSeconds: 5
@@ -76,6 +76,22 @@ spec:
             requests:
               cpu: 50m
               memory: 30M
+          readinessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            initialDelaySeconds: 5
+            periodSeconds: 10
+            successThreshold: 1
+            failureThreshold: 3
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            initialDelaySeconds: 10
+            periodSeconds: 10
+            successThreshold: 1
+            failureThreshold: 5
           volumeMounts:
             - mountPath: /config
               name: gatus-config

.github/codecov.yml

@@ -5,3 +5,8 @@ ignore:
 coverage:
   status:
     patch: off
+    project:
+      default:
+        target: 75%
+        threshold: null
+

.github/workflows/benchmark.yml

@@ -0,0 +1,26 @@
+name: benchmark
+on:
+  workflow_dispatch:
+    inputs:
+      repository:
+        description: "Repository to checkout. Useful for benchmarking a fork. Format should be <owner>/<repository>."
+        required: true
+        default: "TwiN/gatus"
+      ref:
+        description: "Branch, tag or SHA to checkout"
+        required: true
+        default: "master"
+jobs:
+  build:
+    name: benchmark
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/setup-go@v3
+        with:
+          go-version: 1.18
+          repository: "${{ github.event.inputs.repository }}"
+          ref: "${{ github.event.inputs.ref }}"
+      - uses: actions/checkout@v3
+      - name: Benchmark
+        run: go test -bench=. ./storage/store

.github/workflows/build.yml

@@ -10,16 +10,14 @@ on:
       - '*.md'
 jobs:
   build:
-    name: Build
+    name: build
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - name: Set up Go
+      - uses: actions/setup-go@v3
-        uses: actions/setup-go@v2
         with:
-          go-version: 1.17
+          go-version: 1.18
-      - name: Check out code into the Go module directory
+      - uses: actions/checkout@v3
-        uses: actions/checkout@v2
       - name: Build binary to make sure it works
         run: go build -mod vendor
       - name: Test

.github/workflows/publish-experimental.yml

@@ -0,0 +1,27 @@
+name: publish-experimental
+on: [workflow_dispatch]
+jobs:
+  publish-experimental:
+    name: publish-experimental
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v3
+      - name: Get image repository
+        run: echo IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to Docker Registry
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Build and push docker image
+        uses: docker/build-push-action@v3
+        with:
+          platforms: linux/amd64
+          pull: true
+          push: true
+          tags: ${{ env.IMAGE_REPOSITORY }}:experimental

.github/workflows/publish-latest.yml

@@ -4,15 +4,17 @@ on:
     workflows: ["build"]
     branches: [master]
     types: [completed]
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: true
 jobs:
   publish-latest:
-    name: Publish latest
+    name: publish-latest
     runs-on: ubuntu-latest
     if: ${{ github.event.workflow_run.conclusion == 'success' }}
-    timeout-minutes: 30
+    timeout-minutes: 60
     steps:
-      - name: Check out code
+      - uses: actions/checkout@v3
-        uses: actions/checkout@v2
       - name: Get image repository
         run: echo IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
       - name: Set up QEMU
@@ -20,15 +22,14 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
       - name: Login to Docker Registry
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Build and push docker image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
-          platforms: linux/amd64
+          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
           pull: true
           push: true
-          tags: |
+          tags: ${{ env.IMAGE_REPOSITORY }}:latest
-            ${{ env.IMAGE_REPOSITORY }}:latest

.github/workflows/publish-release.yml

@@ -4,12 +4,11 @@ on:
     types: [published]
 jobs:
   publish-release:
-    name: Publish release
+    name: publish-release
     runs-on: ubuntu-latest
-    timeout-minutes: 30
+    timeout-minutes: 60
     steps:
-      - name: Check out code
+      - uses: actions/checkout@v3
-        uses: actions/checkout@v2
       - name: Get image repository
         run: echo IMAGE_REPOSITORY=$(echo ${{ secrets.DOCKER_USERNAME }}/${{ github.event.repository.name }} | tr '[:upper:]' '[:lower:]') >> $GITHUB_ENV
       - name: Get the release
@@ -19,15 +18,14 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1
       - name: Login to Docker Registry
-        uses: docker/login-action@v1
+        uses: docker/login-action@v2
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Build and push docker image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@v3
         with:
           platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
           pull: true
           push: true
-          tags: |
+          tags: ${{ env.IMAGE_REPOSITORY }}:${{ env.RELEASE }},${{ env.IMAGE_REPOSITORY }}:stable
-            ${{ env.IMAGE_REPOSITORY }}:${{ env.RELEASE }}

.gitignore

@@ -1,8 +1,7 @@
 .idea
 .vscode
+*.db
+*.db-shm
+*.db-wal
 gatus
-db.db
 config/config.yml
-db.db-shm
-db.db-wal
-memory.db

Dockerfile

@@ -13,7 +13,6 @@ RUN CGO_ENABLED=0 GOOS=linux go build -mod vendor -a -installsuffix cgo -o gatus
 FROM scratch
 COPY --from=builder /app/gatus .
 COPY --from=builder /app/config.yaml ./config/config.yaml
-COPY --from=builder /app/web/static ./web/static
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
 ENV PORT=8080
 EXPOSE ${PORT}

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2021 TwiN
+   Copyright [yyyy] [name of copyright owner]
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

Makefile

@@ -1,5 +1,8 @@
 BINARY=gatus
 
+# Because there's a folder called "test", we need to make the target "test" phony
+.PHONY: test
+
 install:
 	go build -mod vendor -o $(BINARY) .
 
@@ -10,7 +13,7 @@ clean:
 	rm $(BINARY)
 
 test:
-	sudo go test ./alerting/... ./client/... ./config/... ./controller/... ./core/... ./jsonpath/... ./pattern/... ./security/... ./storage/... ./util/... ./watchdog/... -cover
+	go test ./... -cover
 
 
 ##########

README.md

@@ -1,14 +1,13 @@
-![Gatus](.github/assets/logo-with-name.png)
+![Gatus](.github/assets/logo-with-dark-text.png)
 
 ![build](https://github.com/TwiN/gatus/workflows/build/badge.svg?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/TwiN/gatus?)](https://goreportcard.com/report/github.com/TwiN/gatus)
 [![codecov](https://codecov.io/gh/TwiN/gatus/branch/master/graph/badge.svg)](https://codecov.io/gh/TwiN/gatus)
 [![Go version](https://img.shields.io/github/go-mod/go-version/TwiN/gatus.svg)](https://github.com/TwiN/gatus)
 [![Docker pulls](https://img.shields.io/docker/pulls/twinproduction/gatus.svg)](https://cloud.docker.com/repository/docker/twinproduction/gatus)
-[![Join Discord server](https://img.shields.io/discord/442432928614449155.svg?label=&logo=discord&logoColor=ffffff&color=7389D8&labelColor=6A7EC2)](https://discord.gg/TDfjeHmXDQ)
 [![Follow TwiN](https://img.shields.io/github/followers/TwiN?label=Follow&style=social)](https://github.com/TwiN)
 
-Gatus is a health dashboard that gives you the ability to monitor your services using HTTP, ICMP, TCP, and even DNS
+Gatus is a developer-oriented health dashboard that gives you the ability to monitor your services using HTTP, ICMP, TCP, and even DNS
 queries as well as evaluate the result of said queries by using a list of conditions on values like the status code,
 the response time, the certificate expiration, the body and many others. The icing on top is that each of these health
 checks can be paired with alerting via Slack, PagerDuty, Discord, Twilio and more.
@@ -27,7 +26,10 @@ For more details, see [Usage](#usage)
 
 ![Gatus dashboard conditions](.github/assets/dashboard-conditions.png)
 
-Have any feedback or want to share your good/bad experience with Gatus? Feel free to email me at [feedback@gatus.io](mailto:feedback@gatus.io)
+Have any feedback or questions? [Create a discussion](https://github.com/TwiN/gatus/discussions/new).
+
+Like this project? Please consider [sponsoring me](https://github.com/sponsors/TwiN).
+
 
 ## Table of Contents
 - [Why Gatus?](#why-gatus)
@@ -41,8 +43,13 @@ Have any feedback or want to share your good/bad experience with Gatus? Feel fre
   - [Client configuration](#client-configuration)
   - [Alerting](#alerting)
     - [Configuring Discord alerts](#configuring-discord-alerts)
+    - [Configuring Email alerts](#configuring-email-alerts)
+    - [Configuring Google Chat alerts](#configuring-google-chat-alerts)
+    - [Configuring Matrix alerts](#configuring-matrix-alerts)
     - [Configuring Mattermost alerts](#configuring-mattermost-alerts)
     - [Configuring Messagebird alerts](#configuring-messagebird-alerts)
+    - [Configuring Ntfy alerts](#configuring-ntfy-alerts)
+    - [Configuring Opsgenie alerts](#configuring-opsgenie-alerts)
     - [Configuring PagerDuty alerts](#configuring-pagerduty-alerts)
     - [Configuring Slack alerts](#configuring-slack-alerts)
     - [Configuring Teams alerts](#configuring-teams-alerts)
@@ -51,6 +58,11 @@ Have any feedback or want to share your good/bad experience with Gatus? Feel fre
     - [Configuring custom alerts](#configuring-custom-alerts)
     - [Setting a default alert](#setting-a-default-alert)
   - [Maintenance](#maintenance)
+  - [Security](#security)
+    - [Basic](#basic)
+    - [OIDC](#oidc)
+  - [Metrics](#metrics)
+  - [Remote instances (EXPERIMENTAL)](#remote-instances-experimental)
 - [Deployment](#deployment)
   - [Docker](#docker)
   - [Helm Chart](#helm-chart)
@@ -66,18 +78,20 @@ Have any feedback or want to share your good/bad experience with Gatus? Feel fre
   - [Monitoring an endpoint using DNS queries](#monitoring-an-endpoint-using-dns-queries)
   - [Monitoring an endpoint using STARTTLS](#monitoring-an-endpoint-using-starttls)
   - [Monitoring an endpoint using TLS](#monitoring-an-endpoint-using-tls)
-  - [Basic authentication](#basic-authentication)
+  - [Monitoring domain expiration](#monitoring-domain-expiration)
   - [disable-monitoring-lock](#disable-monitoring-lock)
   - [Reloading configuration on the fly](#reloading-configuration-on-the-fly)
   - [Endpoint groups](#endpoint-groups)
   - [Exposing Gatus on a custom port](#exposing-gatus-on-a-custom-port)
   - [Badges](#badges)
     - [Uptime](#uptime)
+    - [Health](#health)
     - [Response time](#response-time)
   - [API](#api)
   - [High level design overview](#high-level-design-overview)
 - [Sponsors](#sponsors)
 
+
 ## Why Gatus?
 Before getting into the specifics, I want to address the most common question:
 > Why would I use Gatus when I can just use Prometheus’ Alertmanager, Cloudwatch or even Splunk?
@@ -90,8 +104,8 @@ Gatus, on the other hand, allows you to configure health checks for each of your
 monitor these features and potentially alert you before any clients are impacted.
 
 A sign you may want to look into Gatus is by simply asking yourself whether you'd receive an alert if your load balancer
-was to go down right now. Will any of your existing alerts by triggered? Your metrics won’t report an increase in errors
+was to go down right now. Will any of your existing alerts be triggered? Your metrics won’t report an increase in errors
-if there’s no traffic that makes it to your applications. This puts you in a situation where your clients are the ones
+if no traffic makes it to your applications. This puts you in a situation where your clients are the ones
 that will notify you about the degradation of your services rather than you reassuring them that you're working on
 fixing the issue before they even know about it.
 
@@ -101,7 +115,7 @@ The main features of Gatus are:
 - **Highly flexible health check conditions**: While checking the response status may be enough for some use cases, Gatus goes much further and allows you to add conditions on the response time, the response body and even the IP address.
 - **Ability to use Gatus for user acceptance tests**: Thanks to the point above, you can leverage this application to create automated user acceptance tests.
 - **Very easy to configure**: Not only is the configuration designed to be as readable as possible, it's also extremely easy to add a new service or a new endpoint to monitor.
-- **Alerting**: While having a pretty visual dashboard is useful to keep track of the state of your application(s), you probably don't want to stare at it all day. Thus, notifications via Slack, Mattermost, Messagebird, PagerDuty, Twilio and Teams are supported out of the box with the ability to configure a custom alerting provider for any needs you might have, whether it be a different provider or a custom application that manages automated rollbacks.
+- **Alerting**: While having a pretty visual dashboard is useful to keep track of the state of your application(s), you probably don't want to stare at it all day. Thus, notifications via Slack, Mattermost, Messagebird, PagerDuty, Twilio, Google chat and Teams are supported out of the box with the ability to configure a custom alerting provider for any needs you might have, whether it be a different provider or a custom application that manages automated rollbacks.
 - **Metrics**
 - **Low resource consumption**: As with most Go applications, the resource footprint that this application requires is negligibly small.
 - **[Badges](#badges)**: ![Uptime 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/7d/badge.svg) ![Response time 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/24h/badge.svg)
@@ -109,6 +123,7 @@ The main features of Gatus are:
 
 ![Gatus dashboard dark mode](.github/assets/dashboard-dark.png)
 
+
 ## Usage
 By default, the configuration file is expected to be at `config/config.yaml`.
 
@@ -142,7 +157,7 @@ If you want to test it locally, see [Docker](#docker).
 
 ## Configuration
 | Parameter                                       | Description                                                                                                                                        | Default                    |
-|:---------------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
+|:------------------------------------------------|:---------------------------------------------------------------------------------------------------------------------------------------------------|:---------------------------|
 | `debug`                                         | Whether to enable debug logs.                                                                                                                      | `false`                    |
 | `metrics`                                       | Whether to expose metrics at /metrics.                                                                                                             | `false`                    |
 | `storage`                                       | [Storage configuration](#storage)                                                                                                                  | `{}`                       |
@@ -160,7 +175,7 @@ If you want to test it locally, see [Docker](#docker).
 | `endpoints[].dns`                               | Configuration for an endpoint of type DNS. <br />See [Monitoring an endpoint using DNS queries](#monitoring-an-endpoint-using-dns-queries).        | `""`                       |
 | `endpoints[].dns.query-type`                    | Query type (e.g. MX)                                                                                                                               | `""`                       |
 | `endpoints[].dns.query-name`                    | Query name (e.g. example.com)                                                                                                                      | `""`                       |
-| `endpoints[].alerts[].type`               | Type of alert. <br />Valid types: `slack`, `discord`, `pagerduty`, `twilio`, `mattermost`, `messagebird`, `teams` `custom`. | Required `""`  |
+| `endpoints[].alerts[].type`                     | Type of alert. <br />Valid types: `slack`, `discord`, `email`, `googlechat`, `pagerduty`, `twilio`, `mattermost`, `messagebird`, `teams` `custom`. | Required `""`              |
 | `endpoints[].alerts[].enabled`                  | Whether to enable the alert.                                                                                                                       | `false`                    |
 | `endpoints[].alerts[].failure-threshold`        | Number of failures in a row needed before triggering the alert.                                                                                    | `3`                        |
 | `endpoints[].alerts[].success-threshold`        | Number of successes in a row before an ongoing incident is marked as resolved.                                                                     | `2`                        |
@@ -168,28 +183,33 @@ If you want to test it locally, see [Docker](#docker).
 | `endpoints[].alerts[].description`              | Description of the alert. Will be included in the alert sent.                                                                                      | `""`                       |
 | `endpoints[].client`                            | [Client configuration](#client-configuration).                                                                                                     | `{}`                       |
 | `endpoints[].ui`                                | UI configuration at the endpoint level.                                                                                                            | `{}`                       |
-| `endpoints[].ui.hide-hostname`            | Whether to include the hostname in the result.                                | `false`        |
+| `endpoints[].ui.hide-hostname`                  | Whether to hide the hostname in the result.                                                                                                        | `false`                    |
+| `endpoints[].ui.hide-url`                       | Whether to ensure the URL is not displayed in the results. Useful if the URL contains a token.                                                     | `false`                    |
 | `endpoints[].ui.dont-resolve-failed-conditions` | Whether to resolve failed conditions for the UI.                                                                                                   | `false`                    |
+| `endpoints[].ui.badge.reponse-time`             | List of response time thresholds. Each time a threshold is reached, the badge has a different color.                                               | `[50, 200, 300, 500, 750]` |
 | `alerting`                                      | [Alerting configuration](#alerting).                                                                                                               | `{}`                       |
-| `security`                               | Security configuration.                                                       | `{}`           |
+| `security`                                      | [Security configuration](#security).                                                                                                               | `{}`                       |
-| `security.basic`                         | Basic authentication security configuration.                                  | `{}`           |
-| `security.basic.username`                | Username for Basic authentication.                                            | Required `""`  |
-| `security.basic.password-sha512`         | Password's SHA512 hash for Basic authentication.                              | Required `""`  |
 | `disable-monitoring-lock`                       | Whether to [disable the monitoring lock](#disable-monitoring-lock).                                                                                | `false`                    |
 | `skip-invalid-config-update`                    | Whether to ignore invalid configuration update. <br />See [Reloading configuration on the fly](#reloading-configuration-on-the-fly).               | `false`                    |
 | `web`                                           | Web configuration.                                                                                                                                 | `{}`                       |
 | `web.address`                                   | Address to listen on.                                                                                                                              | `0.0.0.0`                  |
 | `web.port`                                      | Port to listen on.                                                                                                                                 | `8080`                     |
 | `ui`                                            | UI configuration.                                                                                                                                  | `{}`                       |
-| `ui.title`                               | Title of the page.                                                            | `Health Dashboard ǀ Gatus`      |
+| `ui.title`                                      | [Title of the document](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/title).                                                          | `Health Dashboard ǀ Gatus` |
-| `ui.logo`                                | URL to the logo to display                                                    | `""`         |
+| `ui.header`                                     | Header at the top of the dashboard.                                                                                                                | `Health Status`            |
+| `ui.logo`                                       | URL to the logo to display.                                                                                                                        | `""`                       |
+| `ui.link`                                       | Link to open when the logo is clicked.                                                                                                             | `""`                       |
+| `ui.buttons`                                    | List of buttons to display below the header.                                                                                                       | `[]`                       |
+| `ui.buttons[].name`                             | Text to display on the button.                                                                                                                     | Required `""`              |
+| `ui.buttons[].link`                             | Link to open when the button is clicked.                                                                                                           | Required `""`              |
+| `maintenance`                                   | [Maintenance configuration](#maintenance).                                                                                                         | `{}`                       |
 
 
 ### Conditions
 Here are some examples of conditions you can use:
 
 | Condition                        | Description                                         | Passing values             | Failing values   |
-|:-----------------------------|:------------------------------------------------------- |:-------------------------- | -------------- |
+|:---------------------------------|:----------------------------------------------------|:---------------------------|------------------|
 | `[STATUS] == 200`                | Status must be equal to 200                         | 200                        | 201, 404, ...    |
 | `[STATUS] < 300`                 | Status must lower than 300                          | 200, 201, 299              | 301, 302, ...    |
 | `[STATUS] <= 299`                | Status must be less than or equal to 299            | 200, 201, 299              | 301, 302, ...    |
@@ -209,37 +229,40 @@ Here are some examples of conditions you can use:
 | `[BODY].name == pat(john*)`      | String at JSONPath `$.name` matches pattern `john*` | `{"name":"john.doe"}`      | `{"name":"bob"}` |
 | `[BODY].id == any(1, 2)`         | Value at JSONPath `$.id` is equal to `1` or `2`     | 1, 2                       | 3, 4, 5          |
 | `[CERTIFICATE_EXPIRATION] > 48h` | Certificate expiration is more than 48h away        | 49h, 50h, 123h             | 1h, 24h, ...     |
+| `[DOMAIN_EXPIRATION] > 720h`     | The domain must expire in more than 720h            | 4000h                      | 1h, 24h, ...     |
 
 
 #### Placeholders
 | Placeholder                | Description                                                                               | Example of resolved value                    |
-|:-------------------------- |:--------------------------------------------------------------- |:------------------------- |
+|:---------------------------|:------------------------------------------------------------------------------------------|:---------------------------------------------|
-| `[STATUS]`                 | Resolves into the HTTP status of the request                    | 404
+| `[STATUS]`                 | Resolves into the HTTP status of the request                                              | `404`                                        |
-| `[RESPONSE_TIME]`          | Resolves into the response time the request took, in ms         | 10
+| `[RESPONSE_TIME]`          | Resolves into the response time the request took, in ms                                   | `10`                                         |
-| `[IP]`                     | Resolves into the IP of the target host                         | 192.168.0.232
+| `[IP]`                     | Resolves into the IP of the target host                                                   | `192.168.0.232`                              |
-| `[BODY]`                   | Resolves into the response body. Supports JSONPath.             | `{"name":"john.doe"}`
+| `[BODY]`                   | Resolves into the response body. Supports JSONPath.                                       | `{"name":"john.doe"}`                        |
-| `[CONNECTED]`              | Resolves into whether a connection could be established         | `true`
+| `[CONNECTED]`              | Resolves into whether a connection could be established                                   | `true`                                       |
-| `[CERTIFICATE_EXPIRATION]` | Resolves into the duration before certificate expiration        | `24h`, `48h`, 0 (if not protocol with certs)
+| `[CERTIFICATE_EXPIRATION]` | Resolves into the duration before certificate expiration (valid units are "s", "m", "h".) | `24h`, `48h`, 0 (if not protocol with certs) |
-| `[DNS_RCODE]`              | Resolves into the DNS status of the response                    | NOERROR
+| `[DOMAIN_EXPIRATION]`      | Resolves into the duration before the domain expires (valid units are "s", "m", "h".)     | `24h`, `48h`, `1234h56m78s`                  |
+| `[DNS_RCODE]`              | Resolves into the DNS status of the response                                              | `NOERROR`                                    |
 
 
 #### Functions
 | Function | Description                                                                                                    | Example                            |
-|:-----------|:---------------------------------------------------------------------------------------------------------------- |:-------------------------- |
+|:---------|:---------------------------------------------------------------------------------------------------------------|:-----------------------------------|
-| `len`      | Returns the length of the object/slice. Works only with the `[BODY]` placeholder.                                | `len([BODY].username) > 8`
+| `len`    | Returns the length of the object/slice. Works only with the `[BODY]` placeholder.                              | `len([BODY].username) > 8`         |
-| `has`      | Returns `true` or `false` based on whether a given path is valid. Works only with the `[BODY]` placeholder.      | `has([BODY].errors) == false`
+| `has`    | Returns `true` or `false` based on whether a given path is valid. Works only with the `[BODY]` placeholder.    | `has([BODY].errors) == false`      |
-| `pat`      | Specifies that the string passed as parameter should be evaluated as a pattern. Works only with `==` and `!=`.   | `[IP] == pat(192.168.*)`
+| `pat`    | Specifies that the string passed as parameter should be evaluated as a pattern. Works only with `==` and `!=`. | `[IP] == pat(192.168.*)`           |
-| `any`      | Specifies that any one of the values passed as parameters is a valid value. Works only with `==` and `!=`.       | `[BODY].ip == any(127.0.0.1, ::1)`
+| `any`    | Specifies that any one of the values passed as parameters is a valid value. Works only with `==` and `!=`.     | `[BODY].ip == any(127.0.0.1, ::1)` |
 
 **NOTE**: Use `pat` only when you need to. `[STATUS] == pat(2*)` is a lot more expensive than `[STATUS] < 300`.
 
 
 ### Storage
 | Parameter         | Description                                                                                                                                        | Default    |
-|:------------------ |:-------------------------------------------------------------------------------------- |:-------------- |
+|:------------------|:---------------------------------------------------------------------------------------------------------------------------------------------------|:-----------|
 | `storage`         | Storage configuration                                                                                                                              | `{}`       |
 | `storage.path`    | Path to persist the data in. Only supported for types `sqlite` and `postgres`.                                                                     | `""`       |
 | `storage.type`    | Type of storage. Valid types: `memory`, `sqlite`, `postgres`.                                                                                      | `"memory"` |
+| `storage.caching` | Whether to use write-through caching. Improves loading time for large dashboards. <br />Only supported if `storage.type` is `sqlite` or `postgres` | `false`    |
 
 - If `storage.type` is `memory` (default):
 ```yaml
@@ -270,10 +293,16 @@ In order to support a wide range of environments, each monitored endpoint has a
 the client used to send the request.
 
 | Parameter                     | Description                                                                | Default         |
-|:-------------------------|:----------------------------------------------------------------------------- |:-------------- |
+|:------------------------------|:---------------------------------------------------------------------------|:----------------|
 | `client.insecure`             | Whether to skip verifying the server's certificate chain and host name.    | `false`         |
 | `client.ignore-redirect`      | Whether to ignore redirects (true) or follow them (false, default).        | `false`         |
 | `client.timeout`              | Duration before timing out.                                                | `10s`           |
+| `client.dns-resolver`         | Override the DNS resolver using the format `{proto}://{host}:{port}`.      | `""`            |
+| `client.oauth2`               | OAuth2 client configuration.                                               | `{}`            |
+| `client.oauth2.token-url`     | The token endpoint URL                                                     | required `""`   |
+| `client.oauth2.client-id`     | The client id which should be used for the `Client credentials flow`       | required `""`   |
+| `client.oauth2.client-secret` | The client secret which should be used for the `Client credentials flow`   | required `""`   |
+| `client.oauth2.scopes[]`      | A list of `scopes` which should be used for the `Client credentials flow`. | required `[""]` |
 
 Note that some of these parameters are ignored based on the type of endpoint. For instance, there's no certificate involved
 in ICMP requests (ping), therefore, setting `client.insecure` to `true` for an endpoint of that type will not do anything.
@@ -300,6 +329,32 @@ endpoints:
       - "[STATUS] == 200"
 ```
 
+This example shows how you can specify a custom DNS resolver:
+```yaml
+endpoints:
+  - name: with-custom-dns-resolver
+    url: "https://your.health.api/health"
+    client:
+      dns-resolver: "tcp://1.1.1.1:53"
+    conditions:
+      - "[STATUS] == 200"
+```
+
+This example shows how you can use the `client.oauth2` configuration to query a backend API with `Bearer token`:
+```yaml
+endpoints:
+  - name: with-custom-oauth2
+    url: "https://your.health.api/health"
+    client:
+      oauth2:
+        token-url: https://your-token-server/token
+        client-id: 00000000-0000-0000-0000-000000000000
+        client-secret: your-client-secret
+        scopes: ['https://your.health.api/.default']
+    conditions:
+      - "[STATUS] == 200"
+```
+
 
 ### Alerting
 Gatus supports multiple alerting providers, such as Slack and PagerDuty, and supports different alerts for each
@@ -309,10 +364,15 @@ Note that if an alerting provider is not properly configured, all alerts configu
 ignored.
 
 | Parameter              | Description                                                                                                                  | Default |
-|:-----------------------|:---------------------------------------------------------------------------------------------------------------------- |:-------|
+|:-----------------------|:-----------------------------------------------------------------------------------------------------------------------------|:--------|
 | `alerting.discord`     | Configuration for alerts of type `discord`. <br />See [Configuring Discord alerts](#configuring-discord-alerts).             | `{}`    |
+| `alerting.email`       | Configuration for alerts of type `email`. <br />See [Configuring Email alerts](#configuring-email-alerts).                   | `{}`    |
+| `alerting.googlechat`  | Configuration for alerts of type `googlechat`. <br />See [Configuring Google Chat alerts](#configuring-google-chat-alerts).  | `{}`    |
+| `alerting.matrix`      | Configuration for alerts of type `matrix`. <br />See [Configuring Matrix alerts](#configuring-matrix-alerts).                | `{}`    |
 | `alerting.mattermost`  | Configuration for alerts of type `mattermost`. <br />See [Configuring Mattermost alerts](#configuring-mattermost-alerts).    | `{}`    |
 | `alerting.messagebird` | Configuration for alerts of type `messagebird`. <br />See [Configuring Messagebird alerts](#configuring-messagebird-alerts). | `{}`    |
+| `alerting.ntfy`        | Configuration for alerts of type `ntfy`. <br />See [Configuring Ntfy alerts](#configuring-ntfy-alerts).                      | `{}`    |
+| `alerting.opsgenie`    | Configuration for alerts of type `opsgenie`. <br />See [Configuring Opsgenie alerts](#configuring-opsgenie-alerts).          | `{}`    |
 | `alerting.pagerduty`   | Configuration for alerts of type `pagerduty`. <br />See [Configuring PagerDuty alerts](#configuring-pagerduty-alerts).       | `{}`    |
 | `alerting.slack`       | Configuration for alerts of type `slack`. <br />See [Configuring Slack alerts](#configuring-slack-alerts).                   | `{}`    |
 | `alerting.teams`       | Configuration for alerts of type `teams`. <br />See [Configuring Teams alerts](#configuring-teams-alerts).                   | `{}`    |
@@ -322,11 +382,15 @@ ignored.
 
 
 #### Configuring Discord alerts
+
 | Parameter                                  | Description                                                                                | Default       |
-|:---------------------------------------- |:-------------------------------------------- |:-------------- |
+|:-------------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
 | `alerting.discord`                         | Configuration for alerts of type `discord`                                                 | `{}`          |
 | `alerting.discord.webhook-url`             | Discord Webhook URL                                                                        | Required `""` |
 | `alerting.discord.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
+| `alerting.discord.overrides`               | List of overrides that may be prioritized over the default configuration                   | `[]`          |
+| `alerting.discord.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
+| `alerting.discord.overrides[].webhook-url` | Discord Webhook URL                                                                        | `""`          |
 
 ```yaml
 alerting:
@@ -336,7 +400,7 @@ alerting:
 endpoints:
   - name: website
     url: "https://twin.sh/health"
-    interval: 30s
+    interval: 5m
     conditions:
       - "[STATUS] == 200"
       - "[BODY].status == UP"
@@ -349,13 +413,143 @@ endpoints:
 ```
 
 
-#### Configuring Mattermost alerts
+#### Configuring Email alerts
+
 | Parameter                          | Description                                                                                | Default       |
 |:-----------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
+| `alerting.email`                   | Configuration for alerts of type `email`                                                   | `{}`          |
+| `alerting.email.from`              | Email used to send the alert                                                               | Required `""` |
+| `alerting.email.username`          | Username of the SMTP server used to send the alert. If empty, uses `alerting.email.from`.  | `""`          |
+| `alerting.email.password`          | Password of the SMTP server used to send the alert                                         | Required `""` |
+| `alerting.email.host`              | Host of the mail server (e.g. `smtp.gmail.com`)                                            | Required `""` |
+| `alerting.email.port`              | Port the mail server is listening to (e.g. `587`)                                          | Required `0`  |
+| `alerting.email.to`                | Email(s) to send the alerts to                                                             | Required `""` |
+| `alerting.email.default-alert`     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
+| `alerting.email.overrides`         | List of overrides that may be prioritized over the default configuration                   | `[]`          |
+| `alerting.email.overrides[].group` | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
+| `alerting.email.overrides[].to`    | Email(s) to send the alerts to                                                             | `""`          |
+
+```yaml
+alerting:
+  email:
+    from: "from@example.com"
+    username: "from@example.com"
+    password: "hunter2"
+    host: "mail.example.com"
+    port: 587
+    to: "recipient1@example.com,recipient2@example.com"
+    # You can also add group-specific to keys, which will
+    # override the to key above for the specified groups
+    overrides:
+      - group: "core"
+        to: "recipient3@example.com,recipient4@example.com"
+
+endpoints:
+  - name: website
+    url: "https://twin.sh/health"
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+      - "[BODY].status == UP"
+      - "[RESPONSE_TIME] < 300"
+    alerts:
+      - type: email
+        enabled: true
+        description: "healthcheck failed"
+        send-on-resolved: true
+
+  - name: back-end
+    group: core
+    url: "https://example.org/"
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+      - "[CERTIFICATE_EXPIRATION] > 48h"
+    alerts:
+      - type: email
+        enabled: true
+        description: "healthcheck failed"
+        send-on-resolved: true
+```
+
+**NOTE:** Some mail servers are painfully slow.
+
+
+#### Configuring Google Chat alerts
+
+| Parameter                                     | Description                                                                                 | Default       |
+|:----------------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
+| `alerting.googlechat`                         | Configuration for alerts of type `googlechat`                                               | `{}`          |
+| `alerting.googlechat.webhook-url`             | Google Chat Webhook URL                                                                     | Required `""` |
+| `alerting.googlechat.client`                  | Client configuration. <br />See [Client configuration](#client-configuration).              | `{}`          |
+| `alerting.googlechat.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
+| `alerting.googlechat.overrides`               | List of overrides that may be prioritized over the default configuration                    | `[]`          |
+| `alerting.googlechat.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
+| `alerting.googlechat.overrides[].webhook-url` | Teams Webhook URL                                                                           | `""`          |
+
+```yaml
+alerting:
+  googlechat:
+    webhook-url: "https://chat.googleapis.com/v1/spaces/*******/messages?key=**********&token=********"
+
+endpoints:
+  - name: website
+    url: "https://twin.sh/health"
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+      - "[BODY].status == UP"
+      - "[RESPONSE_TIME] < 300"
+    alerts:
+      - type: googlechat
+        enabled: true
+        description: "healthcheck failed"
+        send-on-resolved: true
+```
+
+
+#### Configuring Matrix alerts
+| Parameter                                | Description                                                                                | Default                            |
+|:-----------------------------------------|:-------------------------------------------------------------------------------------------|:-----------------------------------|
+| `alerting.matrix`                        | Configuration for alerts of type `matrix`                                                  | `{}`                               |
+| `alerting.matrix.server-url`             | Homeserver URL                                                                             | `https://matrix-client.matrix.org` |
+| `alerting.matrix.access-token`           | Bot user access token (see https://webapps.stackexchange.com/q/131056)                     | Required `""`                      |
+| `alerting.matrix.internal-room-id`       | Internal room ID of room to send alerts to (can be found in Room Settings > Advanced)      | Required `""`                      |
+| `alerting.matrix.default-alert`          | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                                |
+
+```yaml
+alerting:
+  matrix:
+    server-url: "https://matrix-client.matrix.org"
+    access-token: "123456"
+    internal-room-id: "!example:matrix.org"
+
+endpoints:
+  - name: website
+    interval: 5m
+    url: "https://twin.sh/health"
+    conditions:
+      - "[STATUS] == 200"
+      - "[BODY].status == UP"
+      - "[RESPONSE_TIME] < 300"
+    alerts:
+      - type: matrix
+        enabled: true
+        send-on-resolved: true
+        description: "healthcheck failed"
+```
+
+
+#### Configuring Mattermost alerts
+| Parameter                                     | Description                                                                                 | Default       |
+|:----------------------------------------------|:--------------------------------------------------------------------------------------------|:--------------|
 | `alerting.mattermost`                         | Configuration for alerts of type `mattermost`                                               | `{}`          |
 | `alerting.mattermost.webhook-url`             | Mattermost Webhook URL                                                                      | Required `""` |
 | `alerting.mattermost.client`                  | Client configuration. <br />See [Client configuration](#client-configuration).              | `{}`          |
 | `alerting.mattermost.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert). | N/A           |
+| `alerting.mattermost.overrides`               | List of overrides that may be prioritized over the default configuration                    | `[]`          |
+| `alerting.mattermost.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration         | `""`          |
+| `alerting.mattermist.overrides[].webhook-url` | Mattermost Webhook URL                                                                      | `""`          |
 
 ```yaml
 alerting:
@@ -367,7 +561,7 @@ alerting:
 endpoints:
   - name: website
     url: "https://twin.sh/health"
-    interval: 30s
+    interval: 5m
     conditions:
       - "[STATUS] == 200"
       - "[BODY].status == UP"
@@ -386,8 +580,8 @@ Here's an example of what the notifications look like:
 
 #### Configuring Messagebird alerts
 | Parameter                            | Description                                                                                | Default       |
-|:-------------------------------------|:----------------------------------------------------------------------------- |:-------------- |
+|:-------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
-| `alerting.messagebird`               | Settings for alerts of type `messagebird`                                     | `{}`           |
+| `alerting.messagebird`               | Configuration for alerts of type `messagebird`                                             | `{}`          |
 | `alerting.messagebird.access-key`    | Messagebird access key                                                                     | Required `""` |
 | `alerting.messagebird.originator`    | The sender of the message                                                                  | Required `""` |
 | `alerting.messagebird.recipients`    | The recipients of the message                                                              | Required `""` |
@@ -403,7 +597,7 @@ alerting:
 
 endpoints:
   - name: website
-    interval: 30s
+    interval: 5m
     url: "https://twin.sh/health"
     conditions:
       - "[STATUS] == 200"
@@ -418,26 +612,82 @@ endpoints:
 ```
 
 
+#### Configuring Ntfy alerts
+| Parameter                     | Description                                                                                | Default           |
+|:------------------------------|:-------------------------------------------------------------------------------------------|:------------------|
+| `alerting.ntfy`               | Configuration for alerts of type `ntfy`                                                    | `{}`              |
+| `alerting.ntfy.topic`         | Topic at which the alert will be sent                                                      | Required `""`     |
+| `alerting.ntfy.url`           | The URL of the target server                                                               | `https://ntfy.sh` |
+| `alerting.ntfy.priority`      | The priority of the alert                                                                  | `3`               |
+| `alerting.ntfy.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A               |
+
+[ntfy](https://github.com/binwiederhier/ntfy) is an amazing project that allows you to subscribe to desktop
+and mobile notifications, making it an awesome addition to Gatus.
+
+Example:
+```yaml
+alerting:
+  ntfy:
+    topic: "gatus-test-topic"
+    priority: 2
+    default-alert:
+      enabled: true
+      failure-threshold: 3
+      send-on-resolved: true
+
+endpoints:
+  - name: website
+    interval: 5m
+    url: "https://twin.sh/health"
+    conditions:
+      - "[STATUS] == 200"
+      - "[BODY].status == UP"
+      - "[RESPONSE_TIME] < 300"
+    alerts:
+      - type: ntfy
+```
+
+
+#### Configuring Opsgenie alerts
+| Parameter                         | Description                                                                                | Default              |
+|:----------------------------------|:-------------------------------------------------------------------------------------------|:---------------------|
+| `alerting.opsgenie`               | Configuration for alerts of type `opsgenie`                                                | `{}`                 |
+| `alerting.opsgenie.api-key`       | Opsgenie API Key                                                                           | Required `""`        |
+| `alerting.opsgenie.priority`      | Priority level of the alert.                                                               | `P1`                 |
+| `alerting.opsgenie.source`        | Source field of the alert.                                                                 | `gatus`              |
+| `alerting.opsgenie.entity-prefix` | Entity field prefix.                                                                       | `gatus-`             |
+| `alerting.opsgenie.alias-prefix`  | Alias field prefix.                                                                        | `gatus-healthcheck-` |
+| `alerting.opsgenie.tags`          | Tags of alert.                                                                             | `[]`                 |
+| `alerting.opsgenie.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                  |
+
+Opsgenie provider will automatically open and close alerts.
+
+```yaml
+alerting:
+  opsgenie:
+    api-key: "00000000-0000-0000-0000-000000000000"
+```
+
+
 #### Configuring PagerDuty alerts
 | Parameter                                        | Description                                                                                | Default |
-|:------------------------------------------------------ |:----------------------------------------------------------------------------- |:-------------- |
+|:-------------------------------------------------|:-------------------------------------------------------------------------------------------|:--------|
 | `alerting.pagerduty`                             | Configuration for alerts of type `pagerduty`                                               | `{}`    |
 | `alerting.pagerduty.integration-key`             | PagerDuty Events API v2 integration key                                                    | `""`    |
-| `alerting.pagerduty.default-alert`                     | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A       |
 | `alerting.pagerduty.overrides`                   | List of overrides that may be prioritized over the default configuration                   | `[]`    |
 | `alerting.pagerduty.overrides[].group`           | Endpoint group for which the configuration will be overridden by this configuration        | `""`    |
 | `alerting.pagerduty.overrides[].integration-key` | PagerDuty Events API v2 integration key                                                    | `""`    |
+| `alerting.pagerduty.default-alert`               | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A     |
 
 It is highly recommended to set `endpoints[].alerts[].send-on-resolved` to `true` for alerts
 of type `pagerduty`, because unlike other alerts, the operation resulting from setting said
-parameter to `true` will not create another incident, but mark the incident as resolved on
+parameter to `true` will not create another incident but mark the incident as resolved on
 PagerDuty instead.
 
 Behavior:
 - By default, `alerting.pagerduty.integration-key` is used as the integration key
 - If the endpoint being evaluated belongs to a group (`endpoints[].group`) matching the value of `alerting.pagerduty.overrides[].group`, the provider will use that override's integration key instead of `alerting.pagerduty.integration-key`'s
 
-
 ```yaml
 alerting:
   pagerduty:
@@ -483,11 +733,13 @@ endpoints:
 
 #### Configuring Slack alerts
 | Parameter                                 | Description                                                                                | Default       |
-|:-------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
+|:------------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
 | `alerting.slack`                          | Configuration for alerts of type `slack`                                                   | `{}`          |
 | `alerting.slack.webhook-url`              | Slack Webhook URL                                                                          | Required `""` |
 | `alerting.slack.default-alert`            | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
-
+| `alerting.slack.overrides`                | List of overrides that may be prioritized over the default configuration                   | `[]`          |
+| `alerting.slack.overrides[].group`        | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
+| `alerting.slack.overrides[].webhook-url`  | Slack Webhook URL                                                                          | `""`          |
 ```yaml
 alerting:
   slack:
@@ -519,16 +771,25 @@ Here's an example of what the notifications look like:
 
 
 #### Configuring Teams alerts
+
 | Parameter                                | Description                                                                                | Default       |
-|:-------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
+|:-----------------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
 | `alerting.teams`                         | Configuration for alerts of type `teams`                                                   | `{}`          |
 | `alerting.teams.webhook-url`             | Teams Webhook URL                                                                          | Required `""` |
 | `alerting.teams.default-alert`           | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A           |
+| `alerting.teams.overrides`               | List of overrides that may be prioritized over the default configuration                   | `[]`          |
+| `alerting.teams.overrides[].group`       | Endpoint group for which the configuration will be overridden by this configuration        | `""`          |
+| `alerting.teams.overrides[].webhook-url` | Teams Webhook URL                                                                          | `""`          |
 
 ```yaml
 alerting:
   teams:
     webhook-url: "https://********.webhook.office.com/webhookb2/************"
+    # You can also add group-specific to keys, which will
+    # override the to key above for the specified groups
+    overrides:
+      - group: "core"
+        webhook-url: "https://********.webhook.office.com/webhookb3/************"
 
 endpoints:
   - name: website
@@ -543,18 +804,34 @@ endpoints:
         enabled: true
         description: "healthcheck failed"
         send-on-resolved: true
+
+  - name: back-end
+    group: core
+    url: "https://example.org/"
+    interval: 5m
+    conditions:
+      - "[STATUS] == 200"
+      - "[CERTIFICATE_EXPIRATION] > 48h"
+    alerts:
+      - type: teams
+        enabled: true
+        description: "healthcheck failed"
+        send-on-resolved: true
 ```
 
 Here's an example of what the notifications look like:
 
 ![Teams notifications](.github/assets/teams-alerts.png)
 
+
 #### Configuring Telegram alerts
 | Parameter                         | Description                                                                                | Default                    |
-|:----------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
+|:----------------------------------|:-------------------------------------------------------------------------------------------|:---------------------------|
 | `alerting.telegram`               | Configuration for alerts of type `telegram`                                                | `{}`                       |
 | `alerting.telegram.token`         | Telegram Bot Token                                                                         | Required `""`              |
 | `alerting.telegram.id`            | Telegram User ID                                                                           | Required `""`              |
+| `alerting.telegram.api-url`       | Telegram API URL                                                                           | `https://api.telegram.org` |
+| `alerting.telegram.client`        | Client configuration. <br />See [Client configuration](#client-configuration).             | `{}`                       |
 | `alerting.telegram.default-alert` | Default alert configuration. <br />See [Setting a default alert](#setting-a-default-alert) | N/A                        |
 
 ```yaml
@@ -583,7 +860,7 @@ Here's an example of what the notifications look like:
 
 #### Configuring Twilio alerts
 | Parameter                       | Description                                                                                | Default       |
-|:--------------------------------- |:----------------------------------------------------------------------------- |:-------------- |
+|:--------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
 | `alerting.twilio`               | Settings for alerts of type `twilio`                                                       | `{}`          |
 | `alerting.twilio.sid`           | Twilio account SID                                                                         | Required `""` |
 | `alerting.twilio.token`         | Twilio auth token                                                                          | Required `""` |
@@ -618,7 +895,7 @@ endpoints:
 
 #### Configuring custom alerts
 | Parameter                       | Description                                                                                | Default       |
-|:----------------------------------|:----------------------------------------------------------------------------- |:-------------- |
+|:--------------------------------|:-------------------------------------------------------------------------------------------|:--------------|
 | `alerting.custom`               | Configuration for custom actions on failure or alerts                                      | `{}`          |
 | `alerting.custom.url`           | Custom alerting request url                                                                | Required `""` |
 | `alerting.custom.method`        | Request method                                                                             | `GET`         |
@@ -634,15 +911,18 @@ leveraging Gatus, you could have Gatus call that application endpoint when an en
 would then check if the endpoint that started failing was part of the recently deployed application, and if it was,
 then automatically roll it back.
 
-The placeholders `[ALERT_DESCRIPTION]` and `[ENDPOINT_NAME]` are automatically substituted for the alert description and
+Furthermore, you may use the following placeholders in the body (`alerting.custom.body`) and in the url (`alerting.custom.url`):
-the endpoint name. These placeholders can be used in the body (`alerting.custom.body`) and in the url (`alerting.custom.url`).
+- `[ALERT_DESCRIPTION]` (resolved from `endpoints[].alerts[].description`)
+- `[ENDPOINT_NAME]` (resolved from `endpoints[].name`)
+- `[ENDPOINT_GROUP]` (resolved from `endpoints[].group`)
+- `[ENDPOINT_URL]` (resolved from `endpoints[].url`)
 
 If you have an alert using the `custom` provider with `send-on-resolved` set to `true`, you can use the
 `[ALERT_TRIGGERED_OR_RESOLVED]` placeholder to differentiate the notifications.
 The aforementioned placeholder will be replaced by `TRIGGERED` or `RESOLVED` accordingly, though it can be modified
 (details at the end of this section).
 
-For all intents and purpose, we'll configure the custom alert with a Slack webhook, but you can call anything you want.
+For all intents and purposes, we'll configure the custom alert with a Slack webhook, but you can call anything you want.
 ```yaml
 alerting:
   custom:
@@ -650,7 +930,7 @@ alerting:
     method: "POST"
     body: |
       {
-        "text": "[ALERT_TRIGGERED_OR_RESOLVED]: [ENDPOINT_NAME] - [ALERT_DESCRIPTION]"
+        "text": "[ALERT_TRIGGERED_OR_RESOLVED]: [ENDPOINT_GROUP] - [ENDPOINT_NAME] - [ALERT_DESCRIPTION]"
       }
 endpoints:
   - name: website
@@ -773,12 +1053,13 @@ endpoints:
       - type: pagerduty
 ```
 
+
 ### Maintenance
 If you have maintenance windows, you may not want to be annoyed by alerts.
 To do that, you'll have to use the maintenance configuration:
 
 | Parameter              | Description                                                                                                                            | Default       |
-|:----------------------- |:----------------------------------------------------------------------------- |:--------------- |
+|:-----------------------|:---------------------------------------------------------------------------------------------------------------------------------------|:--------------|
 | `maintenance.enabled`  | Whether the maintenance period is enabled                                                                                              | `true`        |
 | `maintenance.start`    | Time at which the maintenance window starts in `hh:mm` format (e.g. `23:00`)                                                           | Required `""` |
 | `maintenance.duration` | Duration of the maintenance window (e.g. `1h`, `30m`)                                                                                  | Required `""` |
@@ -804,6 +1085,99 @@ maintenance:
 ```
 
 
+### Security
+| Parameter                        | Description                  | Default       |
+|:---------------------------------|:-----------------------------|:--------------|
+| `security`                       | Security configuration       | `{}`          |
+| `security.basic`                 | HTTP Basic configuration     | `{}`          |
+| `security.oidc`                  | OpenID Connect configuration | `{}`          |
+
+
+#### Basic
+| Parameter                               | Description                                                                        | Default       |
+|:----------------------------------------|:-----------------------------------------------------------------------------------|:--------------|
+| `security.basic`                        | HTTP Basic configuration                                                           | `{}`          |
+| `security.basic.username`               | Username for Basic authentication.                                                 | Required `""` |
+| `security.basic.password-bcrypt-base64` | Password hashed with Bcrypt and then encoded with base64 for Basic authentication. | Required `""` |
+
+The example below will require that you authenticate with the username `john.doe` and the password `hunter2`:
+```yaml
+security:
+  basic:
+    username: "john.doe"
+    password-bcrypt-base64: "JDJhJDEwJHRiMnRFakxWazZLdXBzRERQazB1TE8vckRLY05Yb1hSdnoxWU0yQ1FaYXZRSW1McmladDYu"
+```
+
+**WARNING:** Make sure to carefully select to cost of the bcrypt hash. The higher the cost, the longer it takes to compute the hash,
+and basic auth verifies the password against the hash on every request. As of 2022-01-08, I suggest a cost of 8.
+
+
+#### OIDC
+| Parameter                        | Description                                                    | Default       |
+|:---------------------------------|:---------------------------------------------------------------|:--------------|
+| `security.oidc`                  | OpenID Connect configuration                                   | `{}`          |
+| `security.oidc.issuer-url`       | Issuer URL                                                     | Required `""` |
+| `security.oidc.redirect-url`     | Redirect URL. Must end with `/authorization-code/callback`     | Required `""` |
+| `security.oidc.client-id`        | Client id                                                      | Required `""` |
+| `security.oidc.client-secret`    | Client secret                                                  | Required `""` |
+| `security.oidc.scopes`           | Scopes to request. The only scope you need is `openid`.        | Required `[]` |
+| `security.oidc.allowed-subjects` | List of subjects to allow. If empty, all subjects are allowed. | `[]`          |
+
+```yaml
+security:
+  oidc:
+    issuer-url: "https://example.okta.com"
+    redirect-url: "https://status.example.com/authorization-code/callback"
+    client-id: "123456789"
+    client-secret: "abcdefghijk"
+    scopes: ["openid"]
+    # You may optionally specify a list of allowed subjects. If this is not specified, all subjects will be allowed.
+    #allowed-subjects: ["johndoe@example.com"]
+```
+
+Confused? Read [Securing Gatus with OIDC using Auth0](https://twin.sh/articles/56/securing-gatus-with-oidc-using-auth0).
+
+
+### Metrics
+To enable metrics, you must set `metrics` to `true`. Doing so will expose Prometheus-friendly metrics at the `/metrics`
+endpoint on the same port your application is configured to run on (`web.port`).
+
+| Metric name                                  | Type    | Description                                                                | Labels                          | Relevant endpoint types |
+|:---------------------------------------------|:--------|:---------------------------------------------------------------------------|:--------------------------------|:------------------------|
+| gatus_results_total                          | counter | Number of results per endpoint                                             | key, group, name, type, success | All                     |
+| gatus_results_code_total                     | counter | Total number of results by code                                            | key, group, name, type, code    | DNS, HTTP               |
+| gatus_results_connected_total                | counter | Total number of results in which a connection was successfully established | key, group, name, type          | All                     |
+| gatus_results_duration_seconds               | gauge   | Duration of the request in seconds                                         | key, group, name, type          | All                     |
+| gatus_results_certificate_expiration_seconds | gauge   | Number of seconds until the certificate expires                            | key, group, name, type          | HTTP, STARTTLS          |
+
+See [examples/docker-compose-grafana-prometheus](.examples/docker-compose-grafana-prometheus) for further documentation as well as an example.
+
+
+### Remote instances (EXPERIMENTAL)
+This feature allows you to retrieve endpoint statuses from a remote Gatus instance.
+
+There are two main use cases for this:
+- You have multiple Gatus instances running on different machines, and you wish to visually expose the statuses through a single dashboard
+- You have one or more Gatus instances that are not publicly accessible (e.g. behind a firewall), and you wish to retrieve 
+
+This is an experimental feature. It may be removed or updated in a breaking manner at any time. Furthermore,
+there are known issues with this feature. If you'd like to provide some feedback, please write a comment in [#64](https://github.com/TwiN/gatus/issues/64).
+Use at your own risk.
+
+| Parameter                          | Description                                  | Default        |
+|:-----------------------------------|:---------------------------------------------|:---------------|
+| `remote`                           | Remote configuration                         | `{}`           |
+| `remote.instances`                 | List of remote instances                     | Required `[]`  |
+| `remote.instances.endpoint-prefix` | String to prefix all endpoint names with     | `""`           |
+| `remote.instances.url`             | URL from which to retrieve endpoint statuses | Required `""`  |
+
+```yaml
+remote:
+  instances:
+    - endpoint-prefix: "status.example.org-"
+      url: "https://status.example.org/api/v1/endpoints/statuses"
+```
+
 
 ## Deployment
 Many examples can be found in the [.examples](.examples) folder, but this section will focus on the most popular ways of deploying Gatus.
@@ -851,7 +1225,6 @@ and [helmfile example](https://github.com/avakarev/gatus-chart#helmfileyaml-exam
 Gatus can be deployed on Terraform by using the following module: [terraform-kubernetes-gatus](https://github.com/TwiN/terraform-kubernetes-gatus).
 
 
-
 ## Running the tests
 ```console
 go test ./... -mod vendor
@@ -898,7 +1271,7 @@ will send a `POST` request to `http://localhost:8080/playground` with the follow
 > tells Gatus to only evaluate one endpoint at a time.
 
 To ensure that Gatus provides reliable and accurate results (i.e. response time), Gatus only evaluates one endpoint at a time
-In other words, even if you have multiple endpoints with the exact same interval, they will not execute at the same time.
+In other words, even if you have multiple endpoints with the same interval, they will not execute at the same time.
 
 You can test this yourself by running Gatus with several endpoints configured with a very short, unrealistic interval,
 such as 1ms. You'll notice that the response time does not fluctuate - that is because while endpoints are evaluated on
@@ -916,19 +1289,19 @@ to respect the configured interval, for instance:
 - Endpoint B has an interval of 5s, and takes 1ms to complete
 - Endpoint B will be unable to run every 5s, because endpoint A's health evaluation takes longer than its interval
 
-To sum it up, while Gatus can really handle any interval you throw at it, you're better off having slow requests with 
+To sum it up, while Gatus can handle any interval you throw at it, you're better off having slow requests with
 higher interval.
 
-As a rule of the thumb, I personally set interval for more complex health checks to `5m` (5 minutes) and 
+As a rule of thumb, I personally set the interval for more complex health checks to `5m` (5 minutes) and
 simple health checks used for alerting (PagerDuty/Twilio) to `30s`.
 
 
 ### Default timeouts
 | Endpoint type  | Timeout |
-|:------------- |:------- |
+|:---------------|:--------|
-| HTTP          | 10s
+| HTTP           | 10s     |
-| TCP           | 10s
+| TCP            | 10s     |
-| ICMP          | 10s
+| ICMP           | 10s     |
 
 To modify the timeout, see [Client configuration](#client-configuration).
 
@@ -948,6 +1321,8 @@ endpoints:
 Placeholders `[STATUS]` and `[BODY]` as well as the fields `endpoints[].body`, `endpoints[].headers`,
 `endpoints[].method` and `endpoints[].graphql` are not supported for TCP endpoints.
 
+This works for applications such as databases (Postgres, MySQL, etc.) and caches (Redis, Memcached, etc.).
+
 **NOTE**: `[CONNECTED] == true` does not guarantee that the endpoint itself is healthy - it only guarantees that there's
 something at the given address listening to the given port, and that a connection to that address was successfully
 established.
@@ -1021,16 +1396,23 @@ endpoints:
 ```
 
 
-### Basic authentication
+### Monitoring domain expiration
-You can require Basic authentication by leveraging the `security.basic` configuration:
+You can monitor the expiration of a domain with all endpoint types except for DNS by using the `[DOMAIN_EXPIRATION]`
+placeholder:
 ```yaml
-security:
+endpoints:
-  basic:
+  - name: check-domain-and-certificate-expiration
-    username: "john.doe"
+    url: "https://example.org"
-    password-sha512: "6b97ed68d14eb3f1aa959ce5d49c7dc612e1eb1dafd73b1e705847483fd6a6c809f2ceb4e8df6ff9984c6298ff0285cace6614bf8daa9f0070101b6c89899e22"
+    interval: 1h
+    conditions:
+      - "[DOMAIN_EXPIRATION] > 720h"
+      - "[CERTIFICATE_EXPIRATION] > 240h"
 ```
 
-The example above will require that you authenticate with the username `john.doe` as well as the password `hunter2`.
+**NOTE**: The usage of the `[DOMAIN_EXPIRATION]` placeholder requires Gatus to send a request to the official IANA WHOIS service [through a library](https://github.com/TwiN/whois)
+and in some cases, a secondary request to a TLD-specific WHOIS server (e.g. `whois.nic.sh`). 
+To prevent the WHOIS service from throttling your IP address if you send too many requests, Gatus will prevent you from
+using the `[DOMAIN_EXPIRATION]` placeholder on an endpoint with an interval of less than `5m`.
 
 
 ### disable-monitoring-lock
@@ -1043,11 +1425,11 @@ There are three main reasons why you might want to disable the monitoring lock:
 - You're using Gatus for load testing (each endpoint are periodically evaluated on a different goroutine, so
 technically, if you create 100 endpoints with a 1 seconds interval, Gatus will send 100 requests per second)
 - You have a _lot_ of endpoints to monitor
-- You want to test multiple endpoints at very short interval (< 5s)
+- You want to test multiple endpoints at very short intervals (< 5s)
 
 
 ### Reloading configuration on the fly
-For the sake on convenience, Gatus automatically reloads the configuration on the fly if the loaded configuration file
+For the sake of convenience, Gatus automatically reloads the configuration on the fly if the loaded configuration file
 is updated while Gatus is running.
 
 By default, the application will exit if the updating configuration is invalid, but you can configure
@@ -1104,7 +1486,7 @@ endpoints:
     conditions:
       - "[STATUS] == 200"
 
-  - name: random endpoint that isn't part of a group
+  - name: random endpoint that is not part of a group
     url: "https://example.org/"
     interval: 5m
     conditions:
@@ -1130,14 +1512,15 @@ web:
   port: ${PORT}
 ```
 
+
 ### Badges
-### Uptime
+#### Uptime
 ![Uptime 1h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/1h/badge.svg)
 ![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)
 ![Uptime 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/7d/badge.svg)
 
-Gatus can automatically generate a SVG badge for one of your monitored endpoints.
+Gatus can automatically generate an SVG badge for one of your monitored endpoints.
-This allows you to put badges in your individual applications' README or even create your own status page, if you 
+This allows you to put badges in your individual applications' README or even create your own status page if you
 desire.
 
 The path to generate a badge is the following:
@@ -1161,10 +1544,27 @@ Example:
 ```
 ![Uptime 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/uptimes/24h/badge.svg)
 ```
-If you'd like to see a visual example of each badges available, you can simply navigate to the endpoint's detail page.
+If you'd like to see a visual example of each badge available, you can simply navigate to the endpoint's detail page.
 
 
-### Response time
+#### Health
+![Health](https://status.twin.sh/api/v1/endpoints/core_blog-external/health/badge.svg)
+
+The path to generate a badge is the following:
+```
+/api/v1/endpoints/{key}/health/badge.svg
+```
+Where:
+- `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,` and `.` replaced by `-`.
+
+For instance, if you want the current status of the endpoint `frontend` in the group `core`,
+the URL would look like this:
+```
+https://example.com/api/v1/endpoints/core_frontend/health/badge.svg
+```
+
+
+#### Response time
 ![Response time 1h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/1h/badge.svg)
 ![Response time 24h](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/24h/badge.svg)
 ![Response time 7d](https://status.twin.sh/api/v1/endpoints/core_blog-external/response-times/7d/badge.svg)
@@ -1178,8 +1578,28 @@ Where:
 - `{key}` has the pattern `<GROUP_NAME>_<ENDPOINT_NAME>` in which both variables have ` `, `/`, `_`, `,` and `.` replaced by `-`.
 
 
+##### How to change the color thresholds of the response time badge  
+To change the response time badges' threshold, a corresponding configuration can be added to an endpoint.   
+The values in the array correspond to the levels [Awesome, Great, Good, Passable, Bad]  
+All five values must be given in milliseconds (ms).  
+
+```
+endpoints:
+- name: nas
+  group: internal
+  url: "https://example.org/"
+  interval: 5m
+  conditions:
+    - "[STATUS] == 200"
+  ui:
+    badge:
+      response-time:
+        thresholds: [550, 850, 1350, 1650, 1750]
+```
+
+
 ### API
-Gatus provides a simple read-only API which can be queried in order to programmatically determine endpoint status and history.
+Gatus provides a simple read-only API that can be queried in order to programmatically determine endpoint status and history.
 
 All endpoints are available via a GET request to the following endpoint:
 ```

alerting/alert/alert.go

@@ -1,5 +1,15 @@
 package alert
 
+import (
+	"errors"
+	"strings"
+)
+
+var (
+	// ErrAlertWithInvalidDescription is the error with which Gatus will panic if an alert has an invalid character
+	ErrAlertWithInvalidDescription = errors.New("alert description must not have \" or \\")
+)
+
 // Alert is a core.Endpoint's alert configuration
 type Alert struct {
 	// Type of alert (required)
@@ -9,7 +19,7 @@ type Alert struct {
 	//
 	// This is a pointer, because it is populated by YAML and we need to know whether it was explicitly set to a value
 	// or not for provider.ParseWithDefaultAlert to work.
-	Enabled *bool `yaml:"enabled"`
+	Enabled *bool `yaml:"enabled,omitempty"`
 
 	// FailureThreshold is the number of failures in a row needed before triggering the alert
 	FailureThreshold int `yaml:"failure-threshold"`
@@ -31,7 +41,7 @@ type Alert struct {
 
 	// ResolveKey is an optional field that is used by some providers (i.e. PagerDuty's dedup_key) to resolve
 	// ongoing/triggered incidents
-	ResolveKey string
+	ResolveKey string `yaml:"-"`
 
 	// Triggered is used to determine whether an alert has been triggered. When an alert is resolved, this value
 	// should be set back to false. It is used to prevent the same alert from going out twice.
@@ -41,7 +51,21 @@ type Alert struct {
 	// applied for alerts that are already triggered and has become "healthy" again is to prevent a case where, for
 	// some reason, the alert provider always returns errors when trying to send the resolved notification
 	// (SendOnResolved).
-	Triggered bool
+	Triggered bool `yaml:"-"`
+}
+
+// ValidateAndSetDefaults validates the alert's configuration and sets the default value of fields that have one
+func (alert *Alert) ValidateAndSetDefaults() error {
+	if alert.FailureThreshold <= 0 {
+		alert.FailureThreshold = 3
+	}
+	if alert.SuccessThreshold <= 0 {
+		alert.SuccessThreshold = 2
+	}
+	if strings.ContainsAny(alert.GetDescription(), "\"\\") {
+		return ErrAlertWithInvalidDescription
+	}
+	return nil
 }
 
 // GetDescription retrieves the description of the alert

alerting/alert/alert_test.go

@@ -1,6 +1,55 @@
 package alert
 
-import "testing"
+import (
+	"testing"
+)
+
+func TestAlert_ValidateAndSetDefaults(t *testing.T) {
+	invalidDescription := "\""
+	scenarios := []struct {
+		name                     string
+		alert                    Alert
+		expectedError            error
+		expectedSuccessThreshold int
+		expectedFailureThreshold int
+	}{
+		{
+			name: "valid-empty",
+			alert: Alert{
+				Description:      nil,
+				FailureThreshold: 0,
+				SuccessThreshold: 0,
+			},
+			expectedError:            nil,
+			expectedFailureThreshold: 3,
+			expectedSuccessThreshold: 2,
+		},
+		{
+			name: "invalid-description",
+			alert: Alert{
+				Description:      &invalidDescription,
+				FailureThreshold: 10,
+				SuccessThreshold: 5,
+			},
+			expectedError:            ErrAlertWithInvalidDescription,
+			expectedFailureThreshold: 10,
+			expectedSuccessThreshold: 5,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			if err := scenario.alert.ValidateAndSetDefaults(); err != scenario.expectedError {
+				t.Errorf("expected error %v, got %v", scenario.expectedError, err)
+			}
+			if scenario.alert.SuccessThreshold != scenario.expectedSuccessThreshold {
+				t.Errorf("expected success threshold %v, got %v", scenario.expectedSuccessThreshold, scenario.alert.SuccessThreshold)
+			}
+			if scenario.alert.FailureThreshold != scenario.expectedFailureThreshold {
+				t.Errorf("expected failure threshold %v, got %v", scenario.expectedFailureThreshold, scenario.alert.FailureThreshold)
+			}
+		})
+	}
+}
 
 func TestAlert_IsEnabled(t *testing.T) {
 	if (Alert{Enabled: nil}).IsEnabled() {

alerting/alert/type.go

@@ -11,12 +11,27 @@ const (
 	// TypeDiscord is the Type for the discord alerting provider
 	TypeDiscord Type = "discord"
 
+	// TypeEmail is the Type for the email alerting provider
+	TypeEmail Type = "email"
+
+	// TypeGoogleChat is the Type for the googlechat alerting provider
+	TypeGoogleChat Type = "googlechat"
+
+	// TypeMatrix is the Type for the matrix alerting provider
+	TypeMatrix Type = "matrix"
+
 	// TypeMattermost is the Type for the mattermost alerting provider
 	TypeMattermost Type = "mattermost"
 
 	// TypeMessagebird is the Type for the messagebird alerting provider
 	TypeMessagebird Type = "messagebird"
 
+	// TypeNtfy is the Type for the ntfy alerting provider
+	TypeNtfy Type = "ntfy"
+
+	// TypeOpsgenie is the Type for the opsgenie alerting provider
+	TypeOpsgenie Type = "opsgenie"
+
 	// TypePagerDuty is the Type for the pagerduty alerting provider
 	TypePagerDuty Type = "pagerduty"
 

alerting/config.go

@@ -1,47 +1,67 @@
 package alerting
 
 import (
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider"
+	"github.com/TwiN/gatus/v4/alerting/provider"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/alerting/provider/custom"
-	"github.com/TwiN/gatus/v3/alerting/provider/discord"
+	"github.com/TwiN/gatus/v4/alerting/provider/discord"
-	"github.com/TwiN/gatus/v3/alerting/provider/mattermost"
+	"github.com/TwiN/gatus/v4/alerting/provider/email"
-	"github.com/TwiN/gatus/v3/alerting/provider/messagebird"
+	"github.com/TwiN/gatus/v4/alerting/provider/googlechat"
-	"github.com/TwiN/gatus/v3/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v4/alerting/provider/matrix"
-	"github.com/TwiN/gatus/v3/alerting/provider/slack"
+	"github.com/TwiN/gatus/v4/alerting/provider/mattermost"
-	"github.com/TwiN/gatus/v3/alerting/provider/teams"
+	"github.com/TwiN/gatus/v4/alerting/provider/messagebird"
-	"github.com/TwiN/gatus/v3/alerting/provider/telegram"
+	"github.com/TwiN/gatus/v4/alerting/provider/ntfy"
-	"github.com/TwiN/gatus/v3/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v4/alerting/provider/opsgenie"
+	"github.com/TwiN/gatus/v4/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v4/alerting/provider/slack"
+	"github.com/TwiN/gatus/v4/alerting/provider/teams"
+	"github.com/TwiN/gatus/v4/alerting/provider/telegram"
+	"github.com/TwiN/gatus/v4/alerting/provider/twilio"
 )
 
 // Config is the configuration for alerting providers
 type Config struct {
 	// Custom is the configuration for the custom alerting provider
-	Custom *custom.AlertProvider `yaml:"custom"`
+	Custom *custom.AlertProvider `yaml:"custom,omitempty"`
+
+	// googlechat is the configuration for the Google chat alerting provider
+	GoogleChat *googlechat.AlertProvider `yaml:"googlechat,omitempty"`
 
 	// Discord is the configuration for the discord alerting provider
-	Discord *discord.AlertProvider `yaml:"discord"`
+	Discord *discord.AlertProvider `yaml:"discord,omitempty"`
+
+	// Email is the configuration for the email alerting provider
+	Email *email.AlertProvider `yaml:"email,omitempty"`
+
+	// Matrix is the configuration for the matrix alerting provider
+	Matrix *matrix.AlertProvider `yaml:"matrix,omitempty"`
 
 	// Mattermost is the configuration for the mattermost alerting provider
-	Mattermost *mattermost.AlertProvider `yaml:"mattermost"`
+	Mattermost *mattermost.AlertProvider `yaml:"mattermost,omitempty"`
 
 	// Messagebird is the configuration for the messagebird alerting provider
-	Messagebird *messagebird.AlertProvider `yaml:"messagebird"`
+	Messagebird *messagebird.AlertProvider `yaml:"messagebird,omitempty"`
+
+	// Ntfy is the configuration for the ntfy alerting provider
+	Ntfy *ntfy.AlertProvider `yaml:"ntfy,omitempty"`
+
+	// Opsgenie is the configuration for the opsgenie alerting provider
+	Opsgenie *opsgenie.AlertProvider `yaml:"opsgenie,omitempty"`
 
 	// PagerDuty is the configuration for the pagerduty alerting provider
-	PagerDuty *pagerduty.AlertProvider `yaml:"pagerduty"`
+	PagerDuty *pagerduty.AlertProvider `yaml:"pagerduty,omitempty"`
 
 	// Slack is the configuration for the slack alerting provider
-	Slack *slack.AlertProvider `yaml:"slack"`
+	Slack *slack.AlertProvider `yaml:"slack,omitempty"`
 
 	// Teams is the configuration for the teams alerting provider
-	Teams *teams.AlertProvider `yaml:"teams"`
+	Teams *teams.AlertProvider `yaml:"teams,omitempty"`
 
 	// Telegram is the configuration for the telegram alerting provider
-	Telegram *telegram.AlertProvider `yaml:"telegram"`
+	Telegram *telegram.AlertProvider `yaml:"telegram,omitempty"`
 
 	// Twilio is the configuration for the twilio alerting provider
-	Twilio *twilio.AlertProvider `yaml:"twilio"`
+	Twilio *twilio.AlertProvider `yaml:"twilio,omitempty"`
 }
 
 // GetAlertingProviderByAlertType returns an provider.AlertProvider by its corresponding alert.Type
@@ -59,6 +79,24 @@ func (config Config) GetAlertingProviderByAlertType(alertType alert.Type) provid
 			return nil
 		}
 		return config.Discord
+	case alert.TypeEmail:
+		if config.Email == nil {
+			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
+			return nil
+		}
+		return config.Email
+	case alert.TypeGoogleChat:
+		if config.GoogleChat == nil {
+			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
+			return nil
+		}
+		return config.GoogleChat
+	case alert.TypeMatrix:
+		if config.Matrix == nil {
+			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
+			return nil
+		}
+		return config.Matrix
 	case alert.TypeMattermost:
 		if config.Mattermost == nil {
 			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
@@ -71,6 +109,18 @@ func (config Config) GetAlertingProviderByAlertType(alertType alert.Type) provid
 			return nil
 		}
 		return config.Messagebird
+	case alert.TypeNtfy:
+		if config.Ntfy == nil {
+			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
+			return nil
+		}
+		return config.Ntfy
+	case alert.TypeOpsgenie:
+		if config.Opsgenie == nil {
+			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil
+			return nil
+		}
+		return config.Opsgenie
 	case alert.TypePagerDuty:
 		if config.PagerDuty == nil {
 			// Since we're returning an interface, we need to explicitly return nil, even if the provider itself is nil

alerting/provider/custom/custom.go

@@ -2,16 +2,14 @@ package custom
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
-	"os"
 	"strings"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/client"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using a custom HTTP request
@@ -24,10 +22,10 @@ type AlertProvider struct {
 	Placeholders map[string]map[string]string `yaml:"placeholders,omitempty"`
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -38,11 +36,6 @@ func (provider *AlertProvider) IsValid() bool {
 	return len(provider.URL) > 0 && provider.ClientConfig != nil
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *AlertProvider {
-	return provider
-}
-
 // GetAlertStatePlaceholderValue returns the Placeholder value for ALERT_TRIGGERED_OR_RESOLVED if configured
 func (provider *AlertProvider) GetAlertStatePlaceholderValue(resolved bool) string {
 	status := "TRIGGERED"
@@ -57,75 +50,45 @@ func (provider *AlertProvider) GetAlertStatePlaceholderValue(resolved bool) stri
 	return status
 }
 
-func (provider *AlertProvider) buildHTTPRequest(endpointName, alertDescription string, resolved bool) *http.Request {
+func (provider *AlertProvider) buildHTTPRequest(endpoint *core.Endpoint, alert *alert.Alert, resolved bool) *http.Request {
-	body := provider.Body
+	body, url, method := provider.Body, provider.URL, provider.Method
-	providerURL := provider.URL
+	body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alert.GetDescription())
-	method := provider.Method
+	url = strings.ReplaceAll(url, "[ALERT_DESCRIPTION]", alert.GetDescription())
-
+	body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", endpoint.Name)
-	if strings.Contains(body, "[ALERT_DESCRIPTION]") {
+	url = strings.ReplaceAll(url, "[ENDPOINT_NAME]", endpoint.Name)
-		body = strings.ReplaceAll(body, "[ALERT_DESCRIPTION]", alertDescription)
+	body = strings.ReplaceAll(body, "[ENDPOINT_GROUP]", endpoint.Group)
-	}
+	url = strings.ReplaceAll(url, "[ENDPOINT_GROUP]", endpoint.Group)
-	if strings.Contains(body, "[SERVICE_NAME]") { // XXX: Remove this in v4.0.0
+	body = strings.ReplaceAll(body, "[ENDPOINT_URL]", endpoint.URL)
-		body = strings.ReplaceAll(body, "[SERVICE_NAME]", endpointName)
+	url = strings.ReplaceAll(url, "[ENDPOINT_URL]", endpoint.URL)
-	}
-	if strings.Contains(body, "[ENDPOINT_NAME]") {
-		body = strings.ReplaceAll(body, "[ENDPOINT_NAME]", endpointName)
-	}
-	if strings.Contains(body, "[ALERT_TRIGGERED_OR_RESOLVED]") {
 	if resolved {
 		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
 	} else {
 		body = strings.ReplaceAll(body, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-		}
+		url = strings.ReplaceAll(url, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-	}
-	if strings.Contains(providerURL, "[ALERT_DESCRIPTION]") {
-		providerURL = strings.ReplaceAll(providerURL, "[ALERT_DESCRIPTION]", alertDescription)
-	}
-	if strings.Contains(providerURL, "[SERVICE_NAME]") { // XXX: Remove this in v4.0.0
-		providerURL = strings.ReplaceAll(providerURL, "[SERVICE_NAME]", endpointName)
-	}
-	if strings.Contains(providerURL, "[ENDPOINT_NAME]") {
-		providerURL = strings.ReplaceAll(providerURL, "[ENDPOINT_NAME]", endpointName)
-	}
-	if strings.Contains(providerURL, "[ALERT_TRIGGERED_OR_RESOLVED]") {
-		if resolved {
-			providerURL = strings.ReplaceAll(providerURL, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(true))
-		} else {
-			providerURL = strings.ReplaceAll(providerURL, "[ALERT_TRIGGERED_OR_RESOLVED]", provider.GetAlertStatePlaceholderValue(false))
-		}
 	}
 	if len(method) == 0 {
 		method = http.MethodGet
 	}
 	bodyBuffer := bytes.NewBuffer([]byte(body))
-	request, _ := http.NewRequest(method, providerURL, bodyBuffer)
+	request, _ := http.NewRequest(method, url, bodyBuffer)
 	for k, v := range provider.Headers {
 		request.Header.Set(k, v)
 	}
 	return request
 }
 
-// Send a request to the alert provider and return the body
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
-func (provider *AlertProvider) Send(endpointName, alertDescription string, resolved bool) ([]byte, error) {
+	request := provider.buildHTTPRequest(endpoint, alert, resolved)
-	if os.Getenv("MOCK_ALERT_PROVIDER") == "true" {
-		if os.Getenv("MOCK_ALERT_PROVIDER_ERROR") == "true" {
-			return nil, errors.New("error")
-		}
-		return []byte("{}"), nil
-	}
-	request := provider.buildHTTPRequest(endpointName, alertDescription, resolved)
 	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	if response.StatusCode > 399 {
-		body, err := ioutil.ReadAll(response.Body)
+		body, _ := io.ReadAll(response.Body)
-		if err != nil {
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
-			return nil, fmt.Errorf("call to provider alert returned status code %d", response.StatusCode)
 	}
-		return nil, fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	return err
-	}
-	return ioutil.ReadAll(response.Body)
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/custom/custom_test.go

@@ -1,106 +1,212 @@
 package custom
 
 import (
-	"io/ioutil"
+	"fmt"
+	"io"
+	"net/http"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestAlertProvider_IsValid(t *testing.T) {
+	t.Run("invalid-provider", func(t *testing.T) {
 		invalidProvider := AlertProvider{URL: ""}
 		if invalidProvider.IsValid() {
 			t.Error("provider shouldn't have been valid")
 		}
+	})
+	t.Run("valid-provider", func(t *testing.T) {
 		validProvider := AlertProvider{URL: "https://example.com"}
+		if validProvider.ClientConfig != nil {
+			t.Error("provider client config should have been nil prior to IsValid() being executed")
+		}
 		if !validProvider.IsValid() {
 			t.Error("provider should've been valid")
 		}
+		if validProvider.ClientConfig == nil {
+			t.Error("provider client config should have been set after IsValid() was executed")
+		}
+	})
 }
 
-func TestAlertProvider_buildHTTPRequestWhenResolved(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	const (
+	defer client.InjectHTTPClient(nil)
-		ExpectedURL  = "https://example.com/endpoint-name?event=RESOLVED&description=alert-description"
+	firstDescription := "description-1"
-		ExpectedBody = "endpoint-name,alert-description,RESOLVED"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
 			)
-	customAlertProvider := &AlertProvider{
+			if scenario.ExpectedError && err == nil {
-		URL:     "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
+				t.Error("expected error, got none")
-		Body:    "[ENDPOINT_NAME],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
-		Headers: nil,
 			}
-	request := customAlertProvider.buildHTTPRequest("endpoint-name", "alert-description", true)
+			if !scenario.ExpectedError && err != nil {
-	if request.URL.String() != ExpectedURL {
+				t.Error("expected no error, got", err.Error())
-		t.Error("expected URL to be", ExpectedURL, "was", request.URL.String())
 			}
-	body, _ := ioutil.ReadAll(request.Body)
+		})
-	if string(body) != ExpectedBody {
-		t.Error("expected body to be", ExpectedBody, "was", string(body))
 	}
 }
 
-func TestAlertProvider_buildHTTPRequestWhenTriggered(t *testing.T) {
+func TestAlertProvider_buildHTTPRequest(t *testing.T) {
-	const (
+	customAlertProvider := &AlertProvider{
-		ExpectedURL  = "https://example.com/endpoint-name?event=TRIGGERED&description=alert-description"
+		URL:  "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]&url=[ENDPOINT_URL]",
-		ExpectedBody = "endpoint-name,alert-description,TRIGGERED"
+		Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ENDPOINT_URL],[ALERT_TRIGGERED_OR_RESOLVED]",
+	}
+	alertDescription := "alert-description"
+	scenarios := []struct {
+		AlertProvider *AlertProvider
+		Resolved      bool
+		ExpectedURL   string
+		ExpectedBody  string
+	}{
+		{
+			AlertProvider: customAlertProvider,
+			Resolved:      true,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=RESOLVED&description=alert-description&url=https://example.com",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,RESOLVED",
+		},
+		{
+			AlertProvider: customAlertProvider,
+			Resolved:      false,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=TRIGGERED&description=alert-description&url=https://example.com",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,https://example.com,TRIGGERED",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(fmt.Sprintf("resolved-%v-with-default-placeholders", scenario.Resolved), func(t *testing.T) {
+			request := customAlertProvider.buildHTTPRequest(
+				&core.Endpoint{Name: "endpoint-name", Group: "endpoint-group", URL: "https://example.com"},
+				&alert.Alert{Description: &alertDescription},
+				scenario.Resolved,
 			)
-	customAlertProvider := &AlertProvider{
+			if request.URL.String() != scenario.ExpectedURL {
-		URL:     "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
+				t.Error("expected URL to be", scenario.ExpectedURL, "got", request.URL.String())
-		Body:    "[ENDPOINT_NAME],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
-		Headers: map[string]string{"Authorization": "Basic hunter2"},
 			}
-	request := customAlertProvider.buildHTTPRequest("endpoint-name", "alert-description", false)
+			body, _ := io.ReadAll(request.Body)
-	if request.URL.String() != ExpectedURL {
+			if string(body) != scenario.ExpectedBody {
-		t.Error("expected URL to be", ExpectedURL, "was", request.URL.String())
+				t.Error("expected body to be", scenario.ExpectedBody, "got", string(body))
 			}
-	body, _ := ioutil.ReadAll(request.Body)
+		})
-	if string(body) != ExpectedBody {
-		t.Error("expected body to be", ExpectedBody, "was", string(body))
-	}
-}
-
-func TestAlertProvider_ToCustomAlertProvider(t *testing.T) {
-	provider := AlertProvider{URL: "https://example.com"}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, true)
-	if customAlertProvider == nil {
-		t.Fatal("customAlertProvider shouldn't have been nil")
-	}
-	if customAlertProvider.URL != "https://example.com" {
-		t.Error("expected URL to be https://example.com, got", customAlertProvider.URL)
 	}
 }
 
 func TestAlertProvider_buildHTTPRequestWithCustomPlaceholder(t *testing.T) {
-	const (
-		ExpectedURL  = "https://example.com/endpoint-name?event=test&description=alert-description"
-		ExpectedBody = "endpoint-name,alert-description,test"
-	)
 	customAlertProvider := &AlertProvider{
-		URL:     "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
+		URL:     "https://example.com/[ENDPOINT_GROUP]/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
-		Body:    "[ENDPOINT_NAME],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+		Body:    "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
 		Headers: nil,
 		Placeholders: map[string]map[string]string{
 			"ALERT_TRIGGERED_OR_RESOLVED": {
-				"RESOLVED": "test",
+				"RESOLVED":  "fixed",
+				"TRIGGERED": "boom",
 			},
 		},
 	}
-	request := customAlertProvider.buildHTTPRequest("endpoint-name", "alert-description", true)
+	alertDescription := "alert-description"
-	if request.URL.String() != ExpectedURL {
+	scenarios := []struct {
-		t.Error("expected URL to be", ExpectedURL, "was", request.URL.String())
+		AlertProvider *AlertProvider
+		Resolved      bool
+		ExpectedURL   string
+		ExpectedBody  string
+	}{
+		{
+			AlertProvider: customAlertProvider,
+			Resolved:      true,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=fixed&description=alert-description",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,fixed",
+		},
+		{
+			AlertProvider: customAlertProvider,
+			Resolved:      false,
+			ExpectedURL:   "https://example.com/endpoint-group/endpoint-name?event=boom&description=alert-description",
+			ExpectedBody:  "endpoint-name,endpoint-group,alert-description,boom",
+		},
 	}
-	body, _ := ioutil.ReadAll(request.Body)
+	for _, scenario := range scenarios {
-	if string(body) != ExpectedBody {
+		t.Run(fmt.Sprintf("resolved-%v-with-custom-placeholders", scenario.Resolved), func(t *testing.T) {
-		t.Error("expected body to be", ExpectedBody, "was", string(body))
+			request := customAlertProvider.buildHTTPRequest(
+				&core.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
+				&alert.Alert{Description: &alertDescription},
+				scenario.Resolved,
+			)
+			if request.URL.String() != scenario.ExpectedURL {
+				t.Error("expected URL to be", scenario.ExpectedURL, "got", request.URL.String())
+			}
+			body, _ := io.ReadAll(request.Body)
+			if string(body) != scenario.ExpectedBody {
+				t.Error("expected body to be", scenario.ExpectedBody, "got", string(body))
+			}
+		})
 	}
 }
 
 func TestAlertProvider_GetAlertStatePlaceholderValueDefaults(t *testing.T) {
 	customAlertProvider := &AlertProvider{
 		URL:  "https://example.com/[ENDPOINT_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
-		Body:         "[ENDPOINT_NAME],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
+		Body: "[ENDPOINT_NAME],[ENDPOINT_GROUP],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
-		Headers:      nil,
-		Placeholders: nil,
 	}
 	if customAlertProvider.GetAlertStatePlaceholderValue(true) != "RESOLVED" {
 		t.Error("expected RESOLVED, got", customAlertProvider.GetAlertStatePlaceholderValue(true))
@@ -110,25 +216,11 @@ func TestAlertProvider_GetAlertStatePlaceholderValueDefaults(t *testing.T) {
 	}
 }
 
-// TestAlertProvider_isBackwardCompatibleWithServiceRename checks if the custom alerting provider still supports
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
-// service placeholders after the migration from "service" to "endpoint"
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
-//
+		t.Error("expected default alert to be not nil")
-// XXX: Remove this in v4.0.0
-func TestAlertProvider_isBackwardCompatibleWithServiceRename(t *testing.T) {
-	const (
-		ExpectedURL  = "https://example.com/endpoint-name?event=TRIGGERED&description=alert-description"
-		ExpectedBody = "endpoint-name,alert-description,TRIGGERED"
-	)
-	customAlertProvider := &AlertProvider{
-		URL:  "https://example.com/[SERVICE_NAME]?event=[ALERT_TRIGGERED_OR_RESOLVED]&description=[ALERT_DESCRIPTION]",
-		Body: "[SERVICE_NAME],[ALERT_DESCRIPTION],[ALERT_TRIGGERED_OR_RESOLVED]",
 	}
-	request := customAlertProvider.buildHTTPRequest("endpoint-name", "alert-description", false)
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
-	if request.URL.String() != ExpectedURL {
+		t.Error("expected default alert to be nil")
-		t.Error("expected URL to be", ExpectedURL, "was", request.URL.String())
-	}
-	body, _ := ioutil.ReadAll(request.Body)
-	if string(body) != ExpectedBody {
-		t.Error("expected body to be", ExpectedBody, "was", string(body))
 	}
 }

alerting/provider/discord/discord.go

@@ -1,12 +1,14 @@
 package discord
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using Discord
@@ -14,23 +16,60 @@ type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group      string `yaml:"group"`
+	WebhookURL string `yaml:"webhook-url"`
 }
 
 // IsValid returns whether the provider's configuration is valid
 func (provider *AlertProvider) IsValid() bool {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
 	return len(provider.WebhookURL) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(endpoint.Group), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
 	var message, results string
 	var colorCode int
 	if resolved {
-		message = fmt.Sprintf("An alert for **%s** has been resolved after passing successfully %d time(s) in a row", endpoint.Name, alert.SuccessThreshold)
+		message = fmt.Sprintf("An alert for **%s** has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
 		colorCode = 3066993
 	} else {
-		message = fmt.Sprintf("An alert for **%s** has been triggered due to having failed %d time(s) in a row", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for **%s** has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
 		colorCode = 15158332
 	}
 	for _, conditionResult := range result.ConditionResults {
@@ -46,10 +85,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
 	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
 		description = ":\\n> " + alertDescription
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{
-		URL:    provider.WebhookURL,
-		Method: http.MethodPost,
-		Body: fmt.Sprintf(`{
   "content": "",
   "embeds": [
     {
@@ -65,9 +101,19 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
       ]
     }
   ]
-}`, message, description, colorCode, results),
+}`, message, description, colorCode, results)
-		Headers: map[string]string{"Content-Type": "application/json"},
 }
+
+// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
+func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.WebhookURL
+			}
+		}
+	}
+	return provider.WebhookURL
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/discord/discord_test.go

@@ -3,11 +3,12 @@ package discord
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestAlertProvider_IsValid(t *testing.T) {
@@ -21,50 +22,237 @@ func TestAlertProvider_IsValid(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.com"}
+	providerWithInvalidOverrideGroup := AlertProvider{
-	alertDescription := "test"
+		Overrides: []Override{
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "svc"}, &alert.Alert{Description: &alertDescription}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+			{
-	if customAlertProvider == nil {
+				WebhookURL: "http://example.com",
-		t.Fatal("customAlertProvider shouldn't have been nil")
+				Group:      "",
+			},
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "resolved") {
+	if providerWithInvalidOverrideGroup.IsValid() {
-		t.Error("customAlertProvider.Body should've contained the substring resolved")
+		t.Error("provider Group shouldn't have been valid")
 	}
-	if customAlertProvider.URL != "http://example.com" {
+	providerWithInvalidOverrideTo := AlertProvider{
-		t.Errorf("expected URL to be %s, got %s", "http://example.com", customAlertProvider.URL)
+		Overrides: []Override{
+			{
+				WebhookURL: "",
+				Group:      "group",
+			},
+		},
 	}
-	if customAlertProvider.Method != http.MethodPost {
+	if providerWithInvalidOverrideTo.IsValid() {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
+		t.Error("provider integration key shouldn't have been valid")
 	}
-	body := make(map[string]interface{})
+	providerWithValidOverride := AlertProvider{
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+		WebhookURL: "http://example.com",
-	if err != nil {
+		Overrides: []Override{
-		t.Error("expected body to be valid JSON, got error:", err.Error())
+			{
+				WebhookURL: "http://example.com",
+				Group:      "group",
+			},
+		},
 	}
-	if expected := "An alert for **svc** has been resolved after passing successfully 0 time(s) in a row:\n> test"; expected != body["embeds"].([]interface{})[0].(map[string]interface{})["description"] {
+	if !providerWithValidOverride.IsValid() {
-		t.Errorf("expected $.embeds[0].description to be %s, got %s", expected, body["embeds"].([]interface{})[0].(map[string]interface{})["description"])
+		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.com"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if customAlertProvider.URL != "http://example.com" {
+			if !scenario.ExpectedError && err != nil {
-		t.Errorf("expected URL to be %s, got %s", "http://example.com", customAlertProvider.URL)
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.Method != http.MethodPost {
+		})
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
 	}
-	body := make(map[string]interface{})
+}
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+
-	if err != nil {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"content\": \"\",\n  \"embeds\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"description\": \"An alert for **endpoint-name** has been triggered due to having failed 3 time(s) in a row:\\n> description-1\",\n      \"color\": 15158332,\n      \"fields\": [\n        {\n          \"name\": \"Condition results\",\n          \"value\": \":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n\",\n          \"inline\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"content\": \"\",\n  \"embeds\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"description\": \"An alert for **endpoint-name** has been resolved after passing successfully 5 time(s) in a row:\\n> description-2\",\n      \"color\": 3066993,\n      \"fields\": [\n        {\n          \"name\": \"Condition results\",\n          \"value\": \":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\n          \"inline\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example01.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
 }

alerting/provider/email/email.go

@@ -0,0 +1,109 @@
+package email
+
+import (
+	"fmt"
+	"math"
+	"strings"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/core"
+	gomail "gopkg.in/mail.v2"
+)
+
+// AlertProvider is the configuration necessary for sending an alert using SMTP
+type AlertProvider struct {
+	From     string `yaml:"from"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+	Host     string `yaml:"host"`
+	Port     int    `yaml:"port"`
+	To       string `yaml:"to"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group string `yaml:"group"`
+	To    string `yaml:"to"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.To) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+
+	return len(provider.From) > 0 && len(provider.Password) > 0 && len(provider.Host) > 0 && len(provider.To) > 0 && provider.Port > 0 && provider.Port < math.MaxUint16
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	var username string
+	if len(provider.Username) > 0 {
+		username = provider.Username
+	} else {
+		username = provider.From
+	}
+	subject, body := provider.buildMessageSubjectAndBody(endpoint, alert, result, resolved)
+	m := gomail.NewMessage()
+	m.SetHeader("From", provider.From)
+	m.SetHeader("To", strings.Split(provider.getToForGroup(endpoint.Group), ",")...)
+	m.SetHeader("Subject", subject)
+	m.SetBody("text/plain", body)
+	d := gomail.NewDialer(provider.Host, provider.Port, username, provider.Password)
+	return d.DialAndSend(m)
+}
+
+// buildMessageSubjectAndBody builds the message subject and body
+func (provider *AlertProvider) buildMessageSubjectAndBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) (string, string) {
+	var subject, message, results string
+	if resolved {
+		subject = fmt.Sprintf("[%s] Alert resolved", endpoint.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
+	} else {
+		subject = fmt.Sprintf("[%s] Alert triggered", endpoint.DisplayName())
+		message = fmt.Sprintf("An alert for %s has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✅"
+		} else {
+			prefix = "❌"
+		}
+		results += fmt.Sprintf("%s %s\n", prefix, conditionResult.Condition)
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = "\n\nAlert description: " + alertDescription
+	}
+	return subject, message + description + "\n\nCondition results:\n" + results
+}
+
+// getToForGroup returns the appropriate email integration to for a given group
+func (provider *AlertProvider) getToForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.To
+			}
+		}
+	}
+	return provider.To
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/email/email_test.go

@@ -0,0 +1,183 @@
+package email
+
+import (
+	"testing"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+func TestAlertDefaultProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{From: "from@example.com", Password: "password", Host: "smtp.gmail.com", Port: 587, To: "to@example.com"}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				To:    "to@example.com",
+				Group: "",
+			},
+		},
+	}
+	if providerWithInvalidOverrideGroup.IsValid() {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithInvalidOverrideTo := AlertProvider{
+		Overrides: []Override{
+			{
+				To:    "",
+				Group: "group",
+			},
+		},
+	}
+	if providerWithInvalidOverrideTo.IsValid() {
+		t.Error("provider integration key shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		From:     "from@example.com",
+		Password: "password",
+		Host:     "smtp.gmail.com",
+		Port:     587,
+		To:       "to@example.com",
+		Overrides: []Override{
+			{
+				To:    "to@example.com",
+				Group: "group",
+			},
+		},
+	}
+	if !providerWithValidOverride.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name            string
+		Provider        AlertProvider
+		Alert           alert.Alert
+		Resolved        bool
+		ExpectedSubject string
+		ExpectedBody    string
+	}{
+		{
+			Name:            "triggered",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        false,
+			ExpectedSubject: "[endpoint-name] Alert triggered",
+			ExpectedBody:    "An alert for endpoint-name has been triggered due to having failed 3 time(s) in a row\n\nAlert description: description-1\n\nCondition results:\n❌ [CONNECTED] == true\n❌ [STATUS] == 200\n",
+		},
+		{
+			Name:            "resolved",
+			Provider:        AlertProvider{},
+			Alert:           alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:        true,
+			ExpectedSubject: "[endpoint-name] Alert resolved",
+			ExpectedBody:    "An alert for endpoint-name has been resolved after passing successfully 5 time(s) in a row\n\nAlert description: description-2\n\nCondition results:\n✅ [CONNECTED] == true\n✅ [STATUS] == 200\n",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			subject, body := scenario.Provider.buildMessageSubjectAndBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if subject != scenario.ExpectedSubject {
+				t.Errorf("expected subject to be %s, got %s", scenario.ExpectedSubject, subject)
+			}
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected body to be %s, got %s", scenario.ExpectedBody, body)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getToForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				To:        "to@example.com",
+				Overrides: nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "to@example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				To:        "to@example.com",
+				Overrides: nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "to@example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				To: "to@example.com",
+				Overrides: []Override{
+					{
+						Group: "group",
+						To:    "to01@example.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "to@example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				To: "to@example.com",
+				Overrides: []Override{
+					{
+						Group: "group",
+						To:    "to01@example.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "to01@example.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getToForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
+}

alerting/provider/googlechat/googlechat.go

@@ -0,0 +1,156 @@
+package googlechat
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+// AlertProvider is the configuration necessary for sending an alert using Google chat
+type AlertProvider struct {
+	WebhookURL string `yaml:"webhook-url"`
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group      string `yaml:"group"`
+	WebhookURL string `yaml:"webhook-url"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	if provider.ClientConfig == nil {
+		provider.ClientConfig = client.GetDefaultConfig()
+	}
+
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+
+	return len(provider.WebhookURL) > 0
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(endpoint.Group), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	var message, color string
+	if resolved {
+		color = "#36A64F"
+		message = fmt.Sprintf("<font color='%s'>An alert has been resolved after passing successfully %d time(s) in a row</font>", color, alert.SuccessThreshold)
+	} else {
+		color = "#DD0000"
+		message = fmt.Sprintf("<font color='%s'>An alert has been triggered due to having failed %d time(s) in a row</font>", color, alert.FailureThreshold)
+	}
+	var results string
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✅"
+		} else {
+			prefix = "❌"
+		}
+		results += fmt.Sprintf("%s   %s<br>", prefix, conditionResult.Condition)
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = ":: " + alertDescription
+	}
+	return fmt.Sprintf(`{
+    "cards": [
+  {
+    "sections": [
+      {
+        "widgets": [
+          {
+            "keyValue": {
+              "topLabel": "%s [%s]",
+              "content": "%s",
+              "contentMultiline": "true",
+              "bottomLabel": "%s",
+              "icon": "BOOKMARK"
+            }
+          },
+          {
+            "keyValue": {
+              "topLabel": "Condition results",
+              "content": "%s",
+              "contentMultiline": "true",
+              "icon": "DESCRIPTION"
+            }
+          },
+          {
+            "buttons": [
+              {
+                "textButton": {
+                  "text": "URL",
+                  "onClick": {
+                    "openLink": {
+                      "url": "%s"
+                    }
+                  }
+                }
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+]
+}`, endpoint.Name, endpoint.Group, message, description, results, endpoint.URL)
+}
+
+// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
+func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.WebhookURL
+			}
+		}
+	}
+	return provider.WebhookURL
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/googlechat/googlechat_test.go

@@ -0,0 +1,260 @@
+package googlechat
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
+)
+
+func TestAlertDefaultProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{WebhookURL: ""}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				WebhookURL: "http://example.com",
+				Group:      "",
+			},
+		},
+	}
+	if providerWithInvalidOverrideGroup.IsValid() {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithInvalidOverrideTo := AlertProvider{
+		Overrides: []Override{
+			{
+				WebhookURL: "",
+				Group:      "group",
+			},
+		},
+	}
+	if providerWithInvalidOverrideTo.IsValid() {
+		t.Error("provider integration key shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		WebhookURL: "http://example.com",
+		Overrides: []Override{
+			{
+				WebhookURL: "http://example.com",
+				Group:      "group",
+			},
+		},
+	}
+	if !providerWithValidOverride.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name", Group: "endpoint-group"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n    \"cards\": [\n  {\n    \"sections\": [\n      {\n        \"widgets\": [\n          {\n            \"keyValue\": {\n              \"topLabel\": \"endpoint-name []\",\n              \"content\": \"\u003cfont color='#DD0000'\u003eAn alert has been triggered due to having failed 3 time(s) in a row\u003c/font\u003e\",\n              \"contentMultiline\": \"true\",\n              \"bottomLabel\": \":: description-1\",\n              \"icon\": \"BOOKMARK\"\n            }\n          },\n          {\n            \"keyValue\": {\n              \"topLabel\": \"Condition results\",\n              \"content\": \"❌   [CONNECTED] == true\u003cbr\u003e❌   [STATUS] == 200\u003cbr\u003e\",\n              \"contentMultiline\": \"true\",\n              \"icon\": \"DESCRIPTION\"\n            }\n          },\n          {\n            \"buttons\": [\n              {\n                \"textButton\": {\n                  \"text\": \"URL\",\n                  \"onClick\": {\n                    \"openLink\": {\n                      \"url\": \"\"\n                    }\n                  }\n                }\n              }\n            ]\n          }\n        ]\n      }\n    ]\n  }\n]\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n    \"cards\": [\n  {\n    \"sections\": [\n      {\n        \"widgets\": [\n          {\n            \"keyValue\": {\n              \"topLabel\": \"endpoint-name []\",\n              \"content\": \"\u003cfont color='#36A64F'\u003eAn alert has been resolved after passing successfully 5 time(s) in a row\u003c/font\u003e\",\n              \"contentMultiline\": \"true\",\n              \"bottomLabel\": \":: description-2\",\n              \"icon\": \"BOOKMARK\"\n            }\n          },\n          {\n            \"keyValue\": {\n              \"topLabel\": \"Condition results\",\n              \"content\": \"✅   [CONNECTED] == true\u003cbr\u003e✅   [STATUS] == 200\u003cbr\u003e\",\n              \"contentMultiline\": \"true\",\n              \"icon\": \"DESCRIPTION\"\n            }\n          },\n          {\n            \"buttons\": [\n              {\n                \"textButton\": {\n                  \"text\": \"URL\",\n                  \"onClick\": {\n                    \"openLink\": {\n                      \"url\": \"\"\n                    }\n                  }\n                }\n              }\n            ]\n          }\n        ]\n      }\n    ]\n  }\n]\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			b, _ := json.Marshal(body)
+			e, _ := json.Marshal(scenario.ExpectedBody)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", e, b)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example01.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
+}

alerting/provider/matrix/matrix.go

@@ -0,0 +1,183 @@
+package matrix
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"math/rand"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+// AlertProvider is the configuration necessary for sending an alert using Matrix
+type AlertProvider struct {
+	MatrixProviderConfig `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group string `yaml:"group"`
+
+	MatrixProviderConfig `yaml:",inline"`
+}
+
+const defaultHomeserverURL = "https://matrix-client.matrix.org"
+
+type MatrixProviderConfig struct {
+	// ServerURL is the custom homeserver to use (optional)
+	ServerURL string `yaml:"server-url"`
+
+	// AccessToken is the bot user's access token to send messages
+	AccessToken string `yaml:"access-token"`
+
+	// InternalRoomID is the room that the bot user has permissions to send messages to
+	InternalRoomID string `yaml:"internal-room-id"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.AccessToken) == 0 || len(override.InternalRoomID) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+	return len(provider.AccessToken) > 0 && len(provider.InternalRoomID) > 0
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	config := provider.getConfigForGroup(endpoint.Group)
+	if config.ServerURL == "" {
+		config.ServerURL = defaultHomeserverURL
+	}
+	// The Matrix endpoint requires a unique transaction ID for each event sent
+	txnId := randStringBytes(24)
+	request, err := http.NewRequest(
+		http.MethodPut,
+		fmt.Sprintf("%s/_matrix/client/v3/rooms/%s/send/m.room.message/%s?access_token=%s",
+			config.ServerURL,
+			url.PathEscape(config.InternalRoomID),
+			txnId,
+			url.QueryEscape(config.AccessToken),
+		),
+		buffer,
+	)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	return fmt.Sprintf(`{
+	"msgtype": "m.text",
+	"format": "org.matrix.custom.html",
+	"body": "%s",
+	"formatted_body": "%s"
+}`,
+		buildPlaintextMessageBody(endpoint, alert, result, resolved),
+		buildHTMLMessageBody(endpoint, alert, result, resolved),
+	)
+}
+
+// buildPlaintextMessageBody builds the message body in plaintext to include in request
+func buildPlaintextMessageBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	var message, results string
+	if resolved {
+		message = fmt.Sprintf("An alert for `%s` has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("An alert for `%s` has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✓"
+		} else {
+			prefix = "✕"
+		}
+		results += fmt.Sprintf("\\n%s - %s", prefix, conditionResult.Condition)
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = "\\n" + alertDescription
+	}
+	return fmt.Sprintf("%s%s\\n%s", message, description, results)
+}
+
+// buildHTMLMessageBody builds the message body in HTML to include in request
+func buildHTMLMessageBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	var message, results string
+	if resolved {
+		message = fmt.Sprintf("An alert for <code>%s</code> has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("An alert for <code>%s</code> has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "✅"
+		} else {
+			prefix = "❌"
+		}
+		results += fmt.Sprintf("<li>%s - <code>%s</code></li>", prefix, conditionResult.Condition)
+	}
+	var description string
+	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
+		description = fmt.Sprintf("\\n<blockquote>%s</blockquote>", alertDescription)
+	}
+	return fmt.Sprintf("<h3>%s</h3>%s\\n<h5>Condition results</h5><ul>%s</ul>", message, description, results)
+}
+
+// getConfigForGroup returns the appropriate configuration for a given group
+func (provider *AlertProvider) getConfigForGroup(group string) MatrixProviderConfig {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.MatrixProviderConfig
+			}
+		}
+	}
+	return provider.MatrixProviderConfig
+}
+
+func randStringBytes(n int) string {
+	// All the compatible characters to use in a transaction ID
+	const availableCharacterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	b := make([]byte, n)
+	rand.Seed(time.Now().UnixNano())
+	for i := range b {
+		b[i] = availableCharacterBytes[rand.Intn(len(availableCharacterBytes))]
+	}
+	return string(b)
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/matrix/matrix_test.go

@@ -0,0 +1,331 @@
+package matrix
+
+import (
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
+)
+
+func TestAlertProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{
+		MatrixProviderConfig: MatrixProviderConfig{
+			AccessToken:    "",
+			InternalRoomID: "",
+		},
+	}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{
+		MatrixProviderConfig: MatrixProviderConfig{
+			AccessToken:    "1",
+			InternalRoomID: "!a:example.com",
+		},
+	}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+	validProviderWithHomeserver := AlertProvider{
+		MatrixProviderConfig: MatrixProviderConfig{
+			ServerURL:      "https://example.com",
+			AccessToken:    "1",
+			InternalRoomID: "!a:example.com",
+		},
+	}
+	if !validProviderWithHomeserver.IsValid() {
+		t.Error("provider with homeserver should've been valid")
+	}
+}
+
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
+	providerWithInvalidOverrideGroup := AlertProvider{
+		Overrides: []Override{
+			{
+				Group: "",
+				MatrixProviderConfig: MatrixProviderConfig{
+					AccessToken:    "",
+					InternalRoomID: "",
+				},
+			},
+		},
+	}
+	if providerWithInvalidOverrideGroup.IsValid() {
+		t.Error("provider Group shouldn't have been valid")
+	}
+	providerWithInvalidOverrideTo := AlertProvider{
+		Overrides: []Override{
+			{
+				Group: "group",
+				MatrixProviderConfig: MatrixProviderConfig{
+					AccessToken:    "",
+					InternalRoomID: "",
+				},
+			},
+		},
+	}
+	if providerWithInvalidOverrideTo.IsValid() {
+		t.Error("provider integration key shouldn't have been valid")
+	}
+	providerWithValidOverride := AlertProvider{
+		MatrixProviderConfig: MatrixProviderConfig{
+			AccessToken:    "1",
+			InternalRoomID: "!a:example.com",
+		},
+		Overrides: []Override{
+			{
+				Group: "group",
+				MatrixProviderConfig: MatrixProviderConfig{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+			},
+		},
+	}
+	if !providerWithValidOverride.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n\t\"msgtype\": \"m.text\",\n\t\"format\": \"org.matrix.custom.html\",\n\t\"body\": \"An alert for `endpoint-name` has been triggered due to having failed 3 time(s) in a row\\ndescription-1\\n\\n✕ - [CONNECTED] == true\\n✕ - [STATUS] == 200\",\n\t\"formatted_body\": \"<h3>An alert for <code>endpoint-name</code> has been triggered due to having failed 3 time(s) in a row</h3>\\n<blockquote>description-1</blockquote>\\n<h5>Condition results</h5><ul><li>❌ - <code>[CONNECTED] == true</code></li><li>❌ - <code>[STATUS] == 200</code></li></ul>\"\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n\t\"msgtype\": \"m.text\",\n\t\"format\": \"org.matrix.custom.html\",\n\t\"body\": \"An alert for `endpoint-name` has been resolved after passing successfully 5 time(s) in a row\\ndescription-2\\n\\n✓ - [CONNECTED] == true\\n✓ - [STATUS] == 200\",\n\t\"formatted_body\": \"<h3>An alert for <code>endpoint-name</code> has been resolved after passing successfully 5 time(s) in a row</h3>\\n<blockquote>description-2</blockquote>\\n<h5>Condition results</h5><ul><li>✅ - <code>[CONNECTED] == true</code></li><li>✅ - <code>[STATUS] == 200</code></li></ul>\"\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getConfigForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput MatrixProviderConfig
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				MatrixProviderConfig: MatrixProviderConfig{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: nil,
+			},
+			InputGroup: "",
+			ExpectedOutput: MatrixProviderConfig{
+				ServerURL:      "https://example.com",
+				AccessToken:    "1",
+				InternalRoomID: "!a:example.com",
+			},
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				MatrixProviderConfig: MatrixProviderConfig{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: nil,
+			},
+			InputGroup: "group",
+			ExpectedOutput: MatrixProviderConfig{
+				ServerURL:      "https://example.com",
+				AccessToken:    "1",
+				InternalRoomID: "!a:example.com",
+			},
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				MatrixProviderConfig: MatrixProviderConfig{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						MatrixProviderConfig: MatrixProviderConfig{
+							ServerURL:      "https://example01.com",
+							AccessToken:    "12",
+							InternalRoomID: "!a:example01.com",
+						},
+					},
+				},
+			},
+			InputGroup: "",
+			ExpectedOutput: MatrixProviderConfig{
+				ServerURL:      "https://example.com",
+				AccessToken:    "1",
+				InternalRoomID: "!a:example.com",
+			},
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				MatrixProviderConfig: MatrixProviderConfig{
+					ServerURL:      "https://example.com",
+					AccessToken:    "1",
+					InternalRoomID: "!a:example.com",
+				},
+				Overrides: []Override{
+					{
+						Group: "group",
+						MatrixProviderConfig: MatrixProviderConfig{
+							ServerURL:      "https://example01.com",
+							AccessToken:    "12",
+							InternalRoomID: "!a:example01.com",
+						},
+					},
+				},
+			},
+			InputGroup: "group",
+			ExpectedOutput: MatrixProviderConfig{
+				ServerURL:      "https://example01.com",
+				AccessToken:    "12",
+				InternalRoomID: "!a:example01.com",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getConfigForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getConfigForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
+}

alerting/provider/mattermost/mattermost.go

@@ -1,13 +1,14 @@
 package mattermost
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/client"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using Mattermost
@@ -15,10 +16,19 @@ type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"`
 
 	// ClientConfig is the configuration of the client used to communicate with the provider's target
-	ClientConfig *client.Config `yaml:"client"`
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group      string `yaml:"group"`
+	WebhookURL string `yaml:"webhook-url"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -26,18 +36,45 @@ func (provider *AlertProvider) IsValid() bool {
 	if provider.ClientConfig == nil {
 		provider.ClientConfig = client.GetDefaultConfig()
 	}
+	if provider.Overrides != nil {
+		registeredGroups := make(map[string]bool)
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
 	return len(provider.WebhookURL) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
-	var message string
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
-	var color string
+	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(endpoint.Group), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	var message, color string
 	if resolved {
-		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.Name, alert.SuccessThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
 		color = "#36A64F"
 	} else {
-		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
 		color = "#DD0000"
 	}
 	var results string
@@ -54,11 +91,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
 	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
 		description = ":\\n> " + alertDescription
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{
-		URL:          provider.WebhookURL,
-		Method:       http.MethodPost,
-		ClientConfig: provider.ClientConfig,
-		Body: fmt.Sprintf(`{
   "text": "",
   "username": "gatus",
   "icon_url": "https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png",
@@ -83,9 +116,19 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
       ]
     }
   ]
-}`, message, message, description, color, endpoint.URL, results),
+}`, message, message, description, color, endpoint.URL, results)
-		Headers: map[string]string{"Content-Type": "application/json"},
 }
+
+// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
+func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.WebhookURL
+			}
+		}
+	}
+	return provider.WebhookURL
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/mattermost/mattermost_test.go

@@ -3,11 +3,12 @@ package mattermost
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestAlertProvider_IsValid(t *testing.T) {
@@ -21,50 +22,241 @@ func TestAlertProvider_IsValid(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.org"}
+	providerWithInvalidOverrideGroup := AlertProvider{
-	alertDescription := "test"
+		Overrides: []Override{
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "svc"}, &alert.Alert{Description: &alertDescription}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+			{
-	if customAlertProvider == nil {
+				WebhookURL: "http://example.com",
-		t.Fatal("customAlertProvider shouldn't have been nil")
+				Group:      "",
+			},
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "resolved") {
+
-		t.Error("customAlertProvider.Body should've contained the substring resolved")
+	if providerWithInvalidOverrideGroup.IsValid() {
+		t.Error("provider Group shouldn't have been valid")
 	}
-	if customAlertProvider.URL != "http://example.org" {
+
-		t.Errorf("expected URL to be %s, got %s", "http://example.org", customAlertProvider.URL)
+	providerWithInvalidOverrideWebHookUrl := AlertProvider{
+		Overrides: []Override{
+			{
+
+				WebhookURL: "",
+				Group:      "group",
+			},
+		},
 	}
-	if customAlertProvider.Method != http.MethodPost {
+	if providerWithInvalidOverrideWebHookUrl.IsValid() {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
+		t.Error("provider WebHookURL shoudn't have been valid")
 	}
-	body := make(map[string]interface{})
+
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+	providerWithValidOverride := AlertProvider{
-	if err != nil {
+		WebhookURL: "http://example.com",
-		t.Error("expected body to be valid JSON, got error:", err.Error())
+		Overrides: []Override{
+			{
+				WebhookURL: "http://example.com",
+				Group:      "group",
+			},
+		},
 	}
-	if expected := "An alert for *svc* has been resolved after passing successfully 0 time(s) in a row:\n> test"; expected != body["attachments"].([]interface{})[0].(map[string]interface{})["text"] {
+	if !providerWithValidOverride.IsValid() {
-		t.Errorf("expected $.attachments[0].description to be %s, got %s", expected, body["attachments"].([]interface{})[0].(map[string]interface{})["text"])
+		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.org"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if customAlertProvider.URL != "http://example.org" {
+			if !scenario.ExpectedError && err != nil {
-		t.Errorf("expected URL to be %s, got %s", "http://example.org", customAlertProvider.URL)
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.Method != http.MethodPost {
+		})
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
 	}
-	body := make(map[string]interface{})
+}
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+
-	if err != nil {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"username\": \"gatus\",\n  \"icon_url\": \"https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png\",\n  \"attachments\": [\n    {\n      \"title\": \":rescue_worker_helmet: Gatus\",\n      \"fallback\": \"Gatus - An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row\",\n      \"text\": \"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n> description-1\",\n      \"short\": false,\n      \"color\": \"#DD0000\",\n      \"fields\": [\n        {\n          \"title\": \"URL\",\n          \"value\": \"\",\n          \"short\": false\n        },\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"username\": \"gatus\",\n  \"icon_url\": \"https://raw.githubusercontent.com/TwiN/gatus/master/.github/assets/logo.png\",\n  \"attachments\": [\n    {\n      \"title\": \":rescue_worker_helmet: Gatus\",\n      \"fallback\": \"Gatus - An alert for *endpoint-name* has been resolved after passing successfully 5 time(s) in a row\",\n      \"text\": \"An alert for *endpoint-name* has been resolved after passing successfully 5 time(s) in a row:\\n> description-2\",\n      \"short\": false,\n      \"color\": \"#36A64F\",\n      \"fields\": [\n        {\n          \"title\": \"URL\",\n          \"value\": \"\",\n          \"short\": false\n        },\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example01.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
 }

alerting/provider/messagebird/messagebird.go

@@ -1,12 +1,15 @@
 package messagebird
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 const (
@@ -20,7 +23,7 @@ type AlertProvider struct {
 	Recipients string `yaml:"recipients"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -28,28 +31,47 @@ func (provider *AlertProvider) IsValid() bool {
 	return len(provider.AccessKey) > 0 && len(provider.Originator) > 0 && len(provider.Recipients) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-// Reference doc for messagebird https://developers.messagebird.com/api/sms-messaging/#send-outbound-sms
+// Reference doc for messagebird: https://developers.messagebird.com/api/sms-messaging/#send-outbound-sms
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer(provider.buildRequestBody(endpoint, alert, result, resolved))
+	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", fmt.Sprintf("AccessKey %s", provider.AccessKey))
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+type Body struct {
+	Originator string `json:"originator"`
+	Recipients string `json:"recipients"`
+	Body       string `json:"body"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) []byte {
 	var message string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
-	}
-	return &custom.AlertProvider{
-		URL:    restAPIURL,
-		Method: http.MethodPost,
-		Body: fmt.Sprintf(`{
-  "originator": "%s",
-  "recipients": "%s",
-  "body": "%s"
-}`, provider.Originator, provider.Recipients, message),
-		Headers: map[string]string{
-			"Content-Type":  "application/json",
-			"Authorization": fmt.Sprintf("AccessKey %s", provider.AccessKey),
-		},
 	}
+	body, _ := json.Marshal(Body{
+		Originator: provider.Originator,
+		Recipients: provider.Recipients,
+		Body:       message,
+	})
+	return body
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/messagebird/messagebird_test.go

@@ -3,11 +3,12 @@ package messagebird
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestMessagebirdAlertProvider_IsValid(t *testing.T) {
@@ -25,54 +26,137 @@ func TestMessagebirdAlertProvider_IsValid(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{
+	defer client.InjectHTTPClient(nil)
-		AccessKey:  "1",
+	firstDescription := "description-1"
-		Originator: "1",
+	secondDescription := "description-2"
-		Recipients: "1",
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, true)
+	for _, scenario := range scenarios {
-	if customAlertProvider == nil {
+		t.Run(scenario.Name, func(t *testing.T) {
-		t.Fatal("customAlertProvider shouldn't have been nil")
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if !strings.Contains(customAlertProvider.Body, "RESOLVED") {
+			if !scenario.ExpectedError && err != nil {
-		t.Error("customAlertProvider.Body should've contained the substring RESOLVED")
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.URL != "https://rest.messagebird.com/messages" {
+		})
-		t.Errorf("expected URL to be %s, got %s", "https://rest.messagebird.com/messages", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
-	provider := AlertProvider{
+	firstDescription := "description-1"
-		AccessKey:  "1",
+	secondDescription := "description-2"
-		Originator: "1",
+	scenarios := []struct {
-		Recipients: "1",
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{AccessKey: "1", Originator: "2", Recipients: "3"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"originator\":\"2\",\"recipients\":\"3\",\"body\":\"TRIGGERED: endpoint-name - description-1\"}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{AccessKey: "4", Originator: "5", Recipients: "6"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"originator\":\"5\",\"recipients\":\"6\",\"body\":\"RESOLVED: endpoint-name - description-2\"}",
+		},
 	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, false)
+	for _, scenario := range scenarios {
-	if customAlertProvider == nil {
+		t.Run(scenario.Name, func(t *testing.T) {
-		t.Fatal("customAlertProvider shouldn't have been nil")
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if string(body) != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
 			}
-	if !strings.Contains(customAlertProvider.Body, "TRIGGERED") {
+			out := make(map[string]interface{})
-		t.Error("customAlertProvider.Body should've contained the substring TRIGGERED")
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
-	}
-	if customAlertProvider.URL != "https://rest.messagebird.com/messages" {
-		t.Errorf("expected URL to be %s, got %s", "https://rest.messagebird.com/messages", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
 }

alerting/provider/ntfy/ntfy.go

@@ -0,0 +1,94 @@
+package ntfy
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+const (
+	DefaultURL      = "https://ntfy.sh"
+	DefaultPriority = 3
+)
+
+// AlertProvider is the configuration necessary for sending an alert using Slack
+type AlertProvider struct {
+	Topic    string `yaml:"topic"`
+	URL      string `yaml:"url,omitempty"`      // Defaults to DefaultURL
+	Priority int    `yaml:"priority,omitempty"` // Defaults to DefaultPriority
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	if len(provider.URL) == 0 {
+		provider.URL = DefaultURL
+	}
+	if provider.Priority == 0 {
+		provider.Priority = DefaultPriority
+	}
+	return len(provider.URL) > 0 && len(provider.Topic) > 0 && provider.Priority > 0 && provider.Priority < 6
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, provider.URL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+type Body struct {
+	Topic    string   `json:"topic"`
+	Title    string   `json:"title"`
+	Message  string   `json:"message"`
+	Tags     []string `json:"tags"`
+	Priority int      `json:"priority"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) []byte {
+	var message, tag string
+	if len(alert.GetDescription()) > 0 {
+		message = endpoint.DisplayName() + " - " + alert.GetDescription()
+	} else {
+		message = endpoint.DisplayName()
+	}
+	if resolved {
+		tag = "white_check_mark"
+	} else {
+		tag = "x"
+	}
+	body, _ := json.Marshal(Body{
+		Topic:    provider.Topic,
+		Title:    "Gatus",
+		Message:  message,
+		Tags:     []string{tag},
+		Priority: provider.Priority,
+	})
+	return body
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}

alerting/provider/ntfy/ntfy_test.go

@@ -0,0 +1,104 @@
+package ntfy
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+func TestAlertDefaultProvider_IsValid(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		provider AlertProvider
+		expected bool
+	}{
+		{
+			name:     "valid",
+			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			expected: true,
+		},
+		{
+			name:     "no-url-should-use-default-value",
+			provider: AlertProvider{Topic: "example", Priority: 1},
+			expected: true,
+		},
+		{
+			name:     "invalid-topic",
+			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "", Priority: 1},
+			expected: false,
+		},
+		{
+			name:     "invalid-priority-too-high",
+			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 6},
+			expected: false,
+		},
+		{
+			name:     "invalid-priority-too-low",
+			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: -1},
+			expected: false,
+		},
+		{
+			name:     "no-priority-should-use-default-value",
+			provider: AlertProvider{URL: "https://ntfy.sh", Topic: "example"},
+			expected: true,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.name, func(t *testing.T) {
+			if scenario.provider.IsValid() != scenario.expected {
+				t.Errorf("expected %t, got %t", scenario.expected, scenario.provider.IsValid())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 1},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"topic\":\"example\",\"title\":\"Gatus\",\"message\":\"endpoint-name - description-1\",\"tags\":[\"x\"],\"priority\":1}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{URL: "https://ntfy.sh", Topic: "example", Priority: 2},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"topic\":\"example\",\"title\":\"Gatus\",\"message\":\"endpoint-name - description-2\",\"tags\":[\"white_check_mark\"],\"priority\":2}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if string(body) != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal(body, &out); err != nil {
+				t.Error("expected body to be valid JSON, got error:", err.Error())
+			}
+		})
+	}
+}

alerting/provider/opsgenie/opsgenie.go

@@ -0,0 +1,240 @@
+package opsgenie
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+)
+
+const (
+	restAPI = "https://api.opsgenie.com/v2/alerts"
+)
+
+type AlertProvider struct {
+	// APIKey to use for
+	APIKey string `yaml:"api-key"`
+
+	// Priority to be used in Opsgenie alert payload
+	//
+	// default: P1
+	Priority string `yaml:"priority"`
+
+	// Source define source to be used in Opsgenie alert payload
+	//
+	// default: gatus
+	Source string `yaml:"source"`
+
+	// EntityPrefix is a prefix to be used in entity argument in Opsgenie alert payload
+	//
+	// default: gatus-
+	EntityPrefix string `yaml:"entity-prefix"`
+
+	//AliasPrefix is a prefix to be used in alias argument in Opsgenie alert payload
+	//
+	// default: gatus-healthcheck-
+	AliasPrefix string `yaml:"alias-prefix"`
+
+	// Tags to be used in Opsgenie alert payload
+	//
+	// default: []
+	Tags []string `yaml:"tags"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+}
+
+// IsValid returns whether the provider's configuration is valid
+func (provider *AlertProvider) IsValid() bool {
+	return len(provider.APIKey) > 0
+}
+
+// Send an alert using the provider
+//
+// Relevant: https://docs.opsgenie.com/docs/alert-api
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	err := provider.createAlert(endpoint, alert, result, resolved)
+	if err != nil {
+		return err
+	}
+	if resolved {
+		err = provider.closeAlert(endpoint, alert)
+		if err != nil {
+			return err
+		}
+	}
+	if alert.IsSendingOnResolved() {
+		if resolved {
+			// The alert has been resolved and there's no error, so we can clear the alert's ResolveKey
+			alert.ResolveKey = ""
+		} else {
+			alert.ResolveKey = provider.alias(buildKey(endpoint))
+		}
+	}
+	return nil
+}
+
+func (provider *AlertProvider) createAlert(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	payload := provider.buildCreateRequestBody(endpoint, alert, result, resolved)
+	_, err := provider.sendRequest(restAPI, http.MethodPost, payload)
+	return err
+}
+
+func (provider *AlertProvider) closeAlert(endpoint *core.Endpoint, alert *alert.Alert) error {
+	payload := provider.buildCloseRequestBody(endpoint, alert)
+	url := restAPI + "/" + provider.alias(buildKey(endpoint)) + "/close?identifierType=alias"
+	_, err := provider.sendRequest(url, http.MethodPost, payload)
+	return err
+}
+
+func (provider *AlertProvider) sendRequest(url, method string, payload interface{}) (*http.Response, error) {
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return nil, fmt.Errorf("fail to build alert payload: %v", payload)
+	}
+	request, err := http.NewRequest(method, url, bytes.NewBuffer(body))
+	if err != nil {
+		return nil, err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	request.Header.Set("Authorization", "GenieKey "+provider.APIKey)
+	res, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode > 399 {
+		rBody, _ := io.ReadAll(res.Body)
+		return nil, fmt.Errorf("call to provider alert returned status code %d: %s", res.StatusCode, string(rBody))
+	}
+	return res, nil
+}
+
+func (provider *AlertProvider) buildCreateRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) alertCreateRequest {
+	var message, description, results string
+	if resolved {
+		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.Name, alert.GetDescription())
+		description = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
+	} else {
+		message = fmt.Sprintf("%s - %s", endpoint.Name, alert.GetDescription())
+		description = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
+	}
+	if endpoint.Group != "" {
+		message = fmt.Sprintf("[%s] %s", endpoint.Group, message)
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "▣"
+		} else {
+			prefix = "▢"
+		}
+		results += fmt.Sprintf("%s - `%s`\n", prefix, conditionResult.Condition)
+	}
+	description = description + "\n" + results
+	key := buildKey(endpoint)
+	details := map[string]string{
+		"endpoint:url":    endpoint.URL,
+		"endpoint:group":  endpoint.Group,
+		"result:hostname": result.Hostname,
+		"result:ip":       result.IP,
+		"result:dns_code": result.DNSRCode,
+		"result:errors":   strings.Join(result.Errors, ","),
+	}
+	for k, v := range details {
+		if v == "" {
+			delete(details, k)
+		}
+	}
+	if result.HTTPStatus > 0 {
+		details["result:http_status"] = strconv.Itoa(result.HTTPStatus)
+	}
+	return alertCreateRequest{
+		Message:     message,
+		Description: description,
+		Source:      provider.source(),
+		Priority:    provider.priority(),
+		Alias:       provider.alias(key),
+		Entity:      provider.entity(key),
+		Tags:        provider.Tags,
+		Details:     details,
+	}
+}
+
+func (provider *AlertProvider) buildCloseRequestBody(endpoint *core.Endpoint, alert *alert.Alert) alertCloseRequest {
+	return alertCloseRequest{
+		Source: buildKey(endpoint),
+		Note:   fmt.Sprintf("RESOLVED: %s - %s", endpoint.Name, alert.GetDescription()),
+	}
+}
+
+func (provider *AlertProvider) source() string {
+	source := provider.Source
+	if source == "" {
+		return "gatus"
+	}
+	return source
+}
+
+func (provider *AlertProvider) alias(key string) string {
+	alias := provider.AliasPrefix
+	if alias == "" {
+		alias = "gatus-healthcheck-"
+	}
+	return alias + key
+}
+
+func (provider *AlertProvider) entity(key string) string {
+	alias := provider.EntityPrefix
+	if alias == "" {
+		alias = "gatus-"
+	}
+	return alias + key
+}
+
+func (provider *AlertProvider) priority() string {
+	priority := provider.Priority
+	if priority == "" {
+		return "P1"
+	}
+	return priority
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+func buildKey(endpoint *core.Endpoint) string {
+	name := toKebabCase(endpoint.Name)
+	if endpoint.Group == "" {
+		return name
+	}
+	return toKebabCase(endpoint.Group) + "-" + name
+}
+
+func toKebabCase(val string) string {
+	return strings.ToLower(strings.ReplaceAll(val, " ", "-"))
+}
+
+type alertCreateRequest struct {
+	Message     string            `json:"message"`
+	Priority    string            `json:"priority"`
+	Source      string            `json:"source"`
+	Entity      string            `json:"entity"`
+	Alias       string            `json:"alias"`
+	Description string            `json:"description"`
+	Tags        []string          `json:"tags,omitempty"`
+	Details     map[string]string `json:"details"`
+}
+
+type alertCloseRequest struct {
+	Source string `json:"source"`
+	Note   string `json:"note"`
+}

alerting/provider/opsgenie/opsgenie_test.go

@@ -0,0 +1,319 @@
+package opsgenie
+
+import (
+	"net/http"
+	"reflect"
+	"testing"
+
+	"github.com/TwiN/gatus/v4/alerting/alert"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
+)
+
+func TestAlertProvider_IsValid(t *testing.T) {
+	invalidProvider := AlertProvider{APIKey: ""}
+	if invalidProvider.IsValid() {
+		t.Error("provider shouldn't have been valid")
+	}
+	validProvider := AlertProvider{APIKey: "00000000-0000-0000-0000-000000000000"}
+	if !validProvider.IsValid() {
+		t.Error("provider should've been valid")
+	}
+}
+
+func TestAlertProvider_Send(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	description := "my bad alert description"
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:          "triggered",
+			Provider:      AlertProvider{},
+			Alert:         alert.Alert{Description: &description, SuccessThreshold: 1, FailureThreshold: 1},
+			Resolved:      false,
+			ExpectedError: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+		},
+		{
+			Name:          "triggered-error",
+			Provider:      AlertProvider{},
+			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:      false,
+			ExpectedError: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+		},
+		{
+			Name:          "resolved",
+			Provider:      AlertProvider{},
+			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:      true,
+			ExpectedError: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+		},
+		{
+			Name:          "resolved-error",
+			Provider:      AlertProvider{},
+			Alert:         alert.Alert{Description: &description, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:      true,
+			ExpectedError: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
+			}
+			if !scenario.ExpectedError && err != nil {
+				t.Error("expected no error, got", err.Error())
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildCreateRequestBody(t *testing.T) {
+	t.Parallel()
+	description := "alert description"
+	scenarios := []struct {
+		Name     string
+		Provider *AlertProvider
+		Alert    *alert.Alert
+		Endpoint *core.Endpoint
+		Result   *core.Result
+		Resolved bool
+		want     alertCreateRequest
+	}{
+		{
+			Name:     "missing all params (unresolved)",
+			Provider: &AlertProvider{},
+			Alert:    &alert.Alert{},
+			Endpoint: &core.Endpoint{},
+			Result:   &core.Result{},
+			Resolved: false,
+			want: alertCreateRequest{
+				Message:     " - ",
+				Priority:    "P1",
+				Source:      "gatus",
+				Entity:      "gatus-",
+				Alias:       "gatus-healthcheck-",
+				Description: "An alert for ** has been triggered due to having failed 0 time(s) in a row\n",
+				Tags:        nil,
+				Details:     map[string]string{},
+			},
+		},
+		{
+			Name:     "missing all params (resolved)",
+			Provider: &AlertProvider{},
+			Alert:    &alert.Alert{},
+			Endpoint: &core.Endpoint{},
+			Result:   &core.Result{},
+			Resolved: true,
+			want: alertCreateRequest{
+				Message:     "RESOLVED:  - ",
+				Priority:    "P1",
+				Source:      "gatus",
+				Entity:      "gatus-",
+				Alias:       "gatus-healthcheck-",
+				Description: "An alert for ** has been resolved after passing successfully 0 time(s) in a row\n",
+				Tags:        nil,
+				Details:     map[string]string{},
+			},
+		},
+		{
+			Name:     "with default options (unresolved)",
+			Provider: &AlertProvider{},
+			Alert: &alert.Alert{
+				Description:      &description,
+				FailureThreshold: 3,
+			},
+			Endpoint: &core.Endpoint{
+				Name: "my super app",
+			},
+			Result: &core.Result{
+				ConditionResults: []*core.ConditionResult{
+					{
+						Condition: "[STATUS] == 200",
+						Success:   true,
+					},
+					{
+						Condition: "[BODY] == OK",
+						Success:   false,
+					},
+				},
+			},
+			Resolved: false,
+			want: alertCreateRequest{
+				Message:     "my super app - " + description,
+				Priority:    "P1",
+				Source:      "gatus",
+				Entity:      "gatus-my-super-app",
+				Alias:       "gatus-healthcheck-my-super-app",
+				Description: "An alert for *my super app* has been triggered due to having failed 3 time(s) in a row\n▣ - `[STATUS] == 200`\n▢ - `[BODY] == OK`\n",
+				Tags:        nil,
+				Details:     map[string]string{},
+			},
+		},
+		{
+			Name: "with custom options (resolved)",
+			Provider: &AlertProvider{
+				Priority:     "P5",
+				EntityPrefix: "oompa-",
+				AliasPrefix:  "loompa-",
+				Source:       "gatus-hc",
+				Tags:         []string{"do-ba-dee-doo"},
+			},
+			Alert: &alert.Alert{
+				Description:      &description,
+				SuccessThreshold: 4,
+			},
+			Endpoint: &core.Endpoint{
+				Name: "my mega app",
+			},
+			Result: &core.Result{
+				ConditionResults: []*core.ConditionResult{
+					{
+						Condition: "[STATUS] == 200",
+						Success:   true,
+					},
+				},
+			},
+			Resolved: true,
+			want: alertCreateRequest{
+				Message:     "RESOLVED: my mega app - " + description,
+				Priority:    "P5",
+				Source:      "gatus-hc",
+				Entity:      "oompa-my-mega-app",
+				Alias:       "loompa-my-mega-app",
+				Description: "An alert for *my mega app* has been resolved after passing successfully 4 time(s) in a row\n▣ - `[STATUS] == 200`\n",
+				Tags:        []string{"do-ba-dee-doo"},
+				Details:     map[string]string{},
+			},
+		},
+		{
+			Name: "with default options and details (unresolved)",
+			Provider: &AlertProvider{
+				Tags: []string{"foo"},
+			},
+			Alert: &alert.Alert{
+				Description:      &description,
+				FailureThreshold: 6,
+			},
+			Endpoint: &core.Endpoint{
+				Name:  "my app",
+				Group: "end game",
+				URL:   "https://my.go/app",
+			},
+			Result: &core.Result{
+				HTTPStatus: 400,
+				Hostname:   "my.go",
+				Errors:     []string{"error 01", "error 02"},
+				Success:    false,
+				ConditionResults: []*core.ConditionResult{
+					{
+						Condition: "[STATUS] == 200",
+						Success:   false,
+					},
+				},
+			},
+			Resolved: false,
+			want: alertCreateRequest{
+				Message:     "[end game] my app - " + description,
+				Priority:    "P1",
+				Source:      "gatus",
+				Entity:      "gatus-end-game-my-app",
+				Alias:       "gatus-healthcheck-end-game-my-app",
+				Description: "An alert for *end game/my app* has been triggered due to having failed 6 time(s) in a row\n▢ - `[STATUS] == 200`\n",
+				Tags:        []string{"foo"},
+				Details: map[string]string{
+					"endpoint:url":       "https://my.go/app",
+					"endpoint:group":     "end game",
+					"result:hostname":    "my.go",
+					"result:errors":      "error 01,error 02",
+					"result:http_status": "400",
+				},
+			},
+		},
+	}
+	for _, scenario := range scenarios {
+		actual := scenario
+		t.Run(actual.Name, func(t *testing.T) {
+			if got := actual.Provider.buildCreateRequestBody(actual.Endpoint, actual.Alert, actual.Result, actual.Resolved); !reflect.DeepEqual(got, actual.want) {
+				t.Errorf("buildCreateRequestBody() = %v, want %v", got, actual.want)
+			}
+		})
+	}
+}
+
+func TestAlertProvider_buildCloseRequestBody(t *testing.T) {
+	t.Parallel()
+	description := "alert description"
+	scenarios := []struct {
+		Name     string
+		Provider *AlertProvider
+		Alert    *alert.Alert
+		Endpoint *core.Endpoint
+		want     alertCloseRequest
+	}{
+		{
+			Name:     "Missing all values",
+			Provider: &AlertProvider{},
+			Alert:    &alert.Alert{},
+			Endpoint: &core.Endpoint{},
+			want: alertCloseRequest{
+				Source: "",
+				Note:   "RESOLVED:  - ",
+			},
+		},
+		{
+			Name:     "Basic values",
+			Provider: &AlertProvider{},
+			Alert: &alert.Alert{
+				Description: &description,
+			},
+			Endpoint: &core.Endpoint{
+				Name: "endpoint name",
+			},
+			want: alertCloseRequest{
+				Source: "endpoint-name",
+				Note:   "RESOLVED: endpoint name - alert description",
+			},
+		},
+	}
+
+	for _, scenario := range scenarios {
+		actual := scenario
+		t.Run(actual.Name, func(t *testing.T) {
+			if got := actual.Provider.buildCloseRequestBody(actual.Endpoint, actual.Alert); !reflect.DeepEqual(got, actual.want) {
+				t.Errorf("buildCloseRequestBody() = %v, want %v", got, actual.want)
+			}
+		})
+	}
+}

alerting/provider/pagerduty/pagerduty.go

@@ -1,12 +1,16 @@
 package pagerduty
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
+	"io"
+	"log"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 const (
@@ -18,10 +22,10 @@ type AlertProvider struct {
 	IntegrationKey string `yaml:"integration-key"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 
 	// Overrides is a list of Override that may be prioritized over the default configuration
-	Overrides []Override `yaml:"overrides"`
+	Overrides []Override `yaml:"overrides,omitempty"`
 }
 
 // Override is a case under which the default integration is overridden
@@ -45,24 +49,56 @@ func (provider *AlertProvider) IsValid() bool {
 	return len(provider.IntegrationKey) == 32 || len(provider.Overrides) != 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
 //
-// relevant: https://developer.pagerduty.com/docs/events-api-v2/trigger-events/
+// Relevant: https://developer.pagerduty.com/docs/events-api-v2/trigger-events/
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, restAPIURL, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	if alert.IsSendingOnResolved() {
+		if resolved {
+			// The alert has been resolved and there's no error, so we can clear the alert's ResolveKey
+			alert.ResolveKey = ""
+		} else {
+			// We need to retrieve the resolve key from the response
+			body, err := io.ReadAll(response.Body)
+			var payload pagerDutyResponsePayload
+			if err = json.Unmarshal(body, &payload); err != nil {
+				// Silently fail. We don't want to create tons of alerts just because we failed to parse the body.
+				log.Printf("[pagerduty][Send] Ran into error unmarshaling pagerduty response: %s", err.Error())
+			} else {
+				alert.ResolveKey = payload.DedupKey
+			}
+		}
+	}
+	return nil
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
 	var message, eventAction, resolveKey string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
 		eventAction = "resolve"
 		resolveKey = alert.ResolveKey
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
 		eventAction = "trigger"
 		resolveKey = ""
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{
-		URL:    restAPIURL,
-		Method: http.MethodPost,
-		Body: fmt.Sprintf(`{
   "routing_key": "%s",
   "dedup_key": "%s",
   "event_action": "%s",
@@ -71,11 +107,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
     "source": "%s",
     "severity": "critical"
   }
-}`, provider.getIntegrationKeyForGroup(endpoint.Group), resolveKey, eventAction, message, endpoint.Name),
+}`, provider.getIntegrationKeyForGroup(endpoint.Group), resolveKey, eventAction, message, endpoint.Name)
-		Headers: map[string]string{
-			"Content-Type": "application/json",
-		},
-	}
 }
 
 // getIntegrationKeyForGroup returns the appropriate pagerduty integration key for a given group
@@ -94,3 +126,9 @@ func (provider *AlertProvider) getIntegrationKeyForGroup(group string) string {
 func (provider AlertProvider) GetDefaultAlert() *alert.Alert {
 	return provider.DefaultAlert
 }
+
+type pagerDutyResponsePayload struct {
+	Status   string `json:"status"`
+	Message  string `json:"message"`
+	DedupKey string `json:"dedup_key"`
+}

alerting/provider/pagerduty/pagerduty_test.go

@@ -3,11 +3,12 @@ package pagerduty
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestAlertProvider_IsValid(t *testing.T) {
@@ -57,108 +58,119 @@ func TestAlertProvider_IsValidWithOverride(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, true)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
-	}
+		Name             string
-	if !strings.Contains(customAlertProvider.Body, "RESOLVED") {
+		Provider         AlertProvider
-		t.Error("customAlertProvider.Body should've contained the substring RESOLVED")
+		Alert            alert.Alert
-	}
+		Resolved         bool
-	if customAlertProvider.URL != "https://events.pagerduty.com/v2/enqueue" {
+		MockRoundTripper test.MockRoundTripper
-		t.Errorf("expected URL to be %s, got %s", "https://events.pagerduty.com/v2/enqueue", customAlertProvider.URL)
+		ExpectedError    bool
-	}
+	}{
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
-	}
-}
-
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlertAndOverride(t *testing.T) {
-	provider := AlertProvider{
-		IntegrationKey: "",
-		Overrides: []Override{
 		{
-				IntegrationKey: "00000000000000000000000000000000",
+			Name:     "triggered",
-				Group:          "group",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
 		},
-		},
-	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, true)
-	if customAlertProvider == nil {
-		t.Fatal("customAlertProvider shouldn't have been nil")
-	}
-	if !strings.Contains(customAlertProvider.Body, "RESOLVED") {
-		t.Error("customAlertProvider.Body should've contained the substring RESOLVED")
-	}
-	if customAlertProvider.URL != "https://events.pagerduty.com/v2/enqueue" {
-		t.Errorf("expected URL to be %s, got %s", "https://events.pagerduty.com/v2/enqueue", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
-	}
-}
-
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
-	provider := AlertProvider{IntegrationKey: "00000000000000000000000000000000"}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, false)
-	if customAlertProvider == nil {
-		t.Fatal("customAlertProvider shouldn't have been nil")
-	}
-	if !strings.Contains(customAlertProvider.Body, "TRIGGERED") {
-		t.Error("customAlertProvider.Body should've contained the substring TRIGGERED")
-	}
-	if customAlertProvider.URL != "https://events.pagerduty.com/v2/enqueue" {
-		t.Errorf("expected URL to be %s, got %s", "https://events.pagerduty.com/v2/enqueue", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
-	}
-}
-
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlertAndOverride(t *testing.T) {
-	provider := AlertProvider{
-		IntegrationKey: "",
-		Overrides: []Override{
 		{
-				IntegrationKey: "00000000000000000000000000000000",
+			Name:     "triggered-error",
-				Group:          "group",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
 		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
 		},
 	}
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{}, false)
+	for _, scenario := range scenarios {
-	if customAlertProvider == nil {
+		t.Run(scenario.Name, func(t *testing.T) {
-		t.Fatal("customAlertProvider shouldn't have been nil")
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if !strings.Contains(customAlertProvider.Body, "TRIGGERED") {
+			if !scenario.ExpectedError && err != nil {
-		t.Error("customAlertProvider.Body should've contained the substring TRIGGERED")
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.URL != "https://events.pagerduty.com/v2/enqueue" {
+		})
-		t.Errorf("expected URL to be %s, got %s", "https://events.pagerduty.com/v2/enqueue", customAlertProvider.URL)
 	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
 }
-	body := make(map[string]interface{})
+
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+func TestAlertProvider_buildRequestBody(t *testing.T) {
-	if err != nil {
+	description := "test"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Alert:        alert.Alert{Description: &description},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"routing_key\": \"00000000000000000000000000000000\",\n  \"dedup_key\": \"\",\n  \"event_action\": \"trigger\",\n  \"payload\": {\n    \"summary\": \"TRIGGERED:  - test\",\n    \"source\": \"\",\n    \"severity\": \"critical\"\n  }\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{IntegrationKey: "00000000000000000000000000000000"},
+			Alert:        alert.Alert{Description: &description, ResolveKey: "key"},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"routing_key\": \"00000000000000000000000000000000\",\n  \"dedup_key\": \"key\",\n  \"event_action\": \"resolve\",\n  \"payload\": {\n    \"summary\": \"RESOLVED:  - test\",\n    \"source\": \"\",\n    \"severity\": \"critical\"\n  }\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(&core.Endpoint{}, &scenario.Alert, &core.Result{}, scenario.Resolved)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
 }
 
 func TestAlertProvider_getIntegrationKeyForGroup(t *testing.T) {
@@ -223,3 +235,12 @@ func TestAlertProvider_getIntegrationKeyForGroup(t *testing.T) {
 		})
 	}
 }
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}

alerting/provider/provider.go

@@ -1,17 +1,22 @@
 package provider
 
 import (
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/alerting/provider/custom"
-	"github.com/TwiN/gatus/v3/alerting/provider/discord"
+	"github.com/TwiN/gatus/v4/alerting/provider/discord"
-	"github.com/TwiN/gatus/v3/alerting/provider/mattermost"
+	"github.com/TwiN/gatus/v4/alerting/provider/email"
-	"github.com/TwiN/gatus/v3/alerting/provider/messagebird"
+	"github.com/TwiN/gatus/v4/alerting/provider/googlechat"
-	"github.com/TwiN/gatus/v3/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v4/alerting/provider/matrix"
-	"github.com/TwiN/gatus/v3/alerting/provider/slack"
+	"github.com/TwiN/gatus/v4/alerting/provider/mattermost"
-	"github.com/TwiN/gatus/v3/alerting/provider/teams"
+	"github.com/TwiN/gatus/v4/alerting/provider/messagebird"
-	"github.com/TwiN/gatus/v3/alerting/provider/telegram"
+	"github.com/TwiN/gatus/v4/alerting/provider/ntfy"
-	"github.com/TwiN/gatus/v3/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v4/alerting/provider/opsgenie"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v4/alerting/provider/slack"
+	"github.com/TwiN/gatus/v4/alerting/provider/teams"
+	"github.com/TwiN/gatus/v4/alerting/provider/telegram"
+	"github.com/TwiN/gatus/v4/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the interface that each providers should implement
@@ -19,11 +24,11 @@ type AlertProvider interface {
 	// IsValid returns whether the provider's configuration is valid
 	IsValid() bool
 
-	// ToCustomAlertProvider converts the provider into a custom.AlertProvider
-	ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider
-
 	// GetDefaultAlert returns the provider's default alert configuration
 	GetDefaultAlert() *alert.Alert
+
+	// Send an alert using the provider
+	Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error
 }
 
 // ParseWithDefaultAlert parses an Endpoint alert by using the provider's default alert as a baseline
@@ -52,8 +57,13 @@ var (
 	// Validate interface implementation on compile
 	_ AlertProvider = (*custom.AlertProvider)(nil)
 	_ AlertProvider = (*discord.AlertProvider)(nil)
+	_ AlertProvider = (*email.AlertProvider)(nil)
+	_ AlertProvider = (*googlechat.AlertProvider)(nil)
+	_ AlertProvider = (*matrix.AlertProvider)(nil)
 	_ AlertProvider = (*mattermost.AlertProvider)(nil)
 	_ AlertProvider = (*messagebird.AlertProvider)(nil)
+	_ AlertProvider = (*ntfy.AlertProvider)(nil)
+	_ AlertProvider = (*opsgenie.AlertProvider)(nil)
 	_ AlertProvider = (*pagerduty.AlertProvider)(nil)
 	_ AlertProvider = (*slack.AlertProvider)(nil)
 	_ AlertProvider = (*teams.AlertProvider)(nil)

alerting/provider/provider_test.go

@@ -3,7 +3,7 @@ package provider
 import (
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
 )
 
 func TestParseWithDefaultAlert(t *testing.T) {

alerting/provider/slack/slack.go

@@ -1,35 +1,72 @@
 package slack
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using Slack
 type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"` // Slack webhook URL
-
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group      string `yaml:"group"`
+	WebhookURL string `yaml:"webhook-url"`
 }
 
 // IsValid returns whether the provider's configuration is valid
 func (provider *AlertProvider) IsValid() bool {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
 	return len(provider.WebhookURL) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(endpoint.Group), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
 	var message, color, results string
 	if resolved {
-		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.Name, alert.SuccessThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
 		color = "#36A64F"
 	} else {
-		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
 		color = "#DD0000"
 	}
 	for _, conditionResult := range result.ConditionResults {
@@ -45,10 +82,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
 	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
 		description = ":\\n> " + alertDescription
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{
-		URL:    provider.WebhookURL,
-		Method: http.MethodPost,
-		Body: fmt.Sprintf(`{
   "text": "",
   "attachments": [
     {
@@ -65,9 +99,19 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
       ]
     }
   ]
-}`, message, description, color, results),
+}`, message, description, color, results)
-		Headers: map[string]string{"Content-Type": "application/json"},
 }
+
+// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
+func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.WebhookURL
+			}
+		}
+	}
+	return provider.WebhookURL
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/slack/slack_test.go

@@ -3,68 +3,275 @@ package slack
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertDefaultProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{WebhookURL: ""}
 	if invalidProvider.IsValid() {
 		t.Error("provider shouldn't have been valid")
 	}
-	validProvider := AlertProvider{WebhookURL: "http://example.com"}
+	validProvider := AlertProvider{WebhookURL: "https://example.com"}
 	if !validProvider.IsValid() {
 		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.com"}
+	providerWithInvalidOverrideGroup := AlertProvider{
-	alertDescription := "test"
+		Overrides: []Override{
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "svc"}, &alert.Alert{Description: &alertDescription}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+			{
-	if customAlertProvider == nil {
+				WebhookURL: "http://example.com",
-		t.Fatal("customAlertProvider shouldn't have been nil")
+				Group:      "",
+			},
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "resolved") {
+	if providerWithInvalidOverrideGroup.IsValid() {
-		t.Error("customAlertProvider.Body should've contained the substring resolved")
+		t.Error("provider Group shouldn't have been valid")
 	}
-	if customAlertProvider.URL != "http://example.com" {
+	providerWithInvalidOverrideTo := AlertProvider{
-		t.Errorf("expected URL to be %s, got %s", "http://example.com", customAlertProvider.URL)
+		Overrides: []Override{
+			{
+				WebhookURL: "",
+				Group:      "group",
+			},
+		},
 	}
-	if customAlertProvider.Method != http.MethodPost {
+	if providerWithInvalidOverrideTo.IsValid() {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
+		t.Error("provider integration key shouldn't have been valid")
 	}
-	body := make(map[string]interface{})
+	providerWithValidOverride := AlertProvider{
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+		WebhookURL: "http://example.com",
-	if err != nil {
+		Overrides: []Override{
-		t.Error("expected body to be valid JSON, got error:", err.Error())
+			{
+				WebhookURL: "http://example.com",
+				Group:      "group",
+			},
+		},
 	}
-	if expected := "An alert for *svc* has been resolved after passing successfully 0 time(s) in a row:\n> test"; expected != body["attachments"].([]interface{})[0].(map[string]interface{})["text"] {
+	if !providerWithValidOverride.IsValid() {
-		t.Errorf("expected $.attachments[0].description to be %s, got %s", expected, body["attachments"].([]interface{})[0].(map[string]interface{})["text"])
+		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.com"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if customAlertProvider.URL != "http://example.com" {
+			if !scenario.ExpectedError && err != nil {
-		t.Errorf("expected URL to be %s, got %s", "http://example.com", customAlertProvider.URL)
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.Method != http.MethodPost {
+		})
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
 	}
-	body := make(map[string]interface{})
+}
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+
-	if err != nil {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Endpoint     core.Endpoint
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Endpoint:     core.Endpoint{Name: "name"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"attachments\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"text\": \"An alert for *name* has been triggered due to having failed 3 time(s) in a row:\\n> description-1\",\n      \"short\": false,\n      \"color\": \"#DD0000\",\n      \"fields\": [\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+		{
+			Name:         "triggered-with-group",
+			Provider:     AlertProvider{},
+			Endpoint:     core.Endpoint{Name: "name", Group: "group"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"attachments\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"text\": \"An alert for *group/name* has been triggered due to having failed 3 time(s) in a row:\\n> description-1\",\n      \"short\": false,\n      \"color\": \"#DD0000\",\n      \"fields\": [\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":x: - `[CONNECTED] == true`\\n:x: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Endpoint:     core.Endpoint{Name: "name"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"attachments\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"text\": \"An alert for *name* has been resolved after passing successfully 5 time(s) in a row:\\n> description-2\",\n      \"short\": false,\n      \"color\": \"#36A64F\",\n      \"fields\": [\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+		{
+			Name:         "resolved-with-group",
+			Provider:     AlertProvider{},
+			Endpoint:     core.Endpoint{Name: "name", Group: "group"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"text\": \"\",\n  \"attachments\": [\n    {\n      \"title\": \":helmet_with_white_cross: Gatus\",\n      \"text\": \"An alert for *group/name* has been resolved after passing successfully 5 time(s) in a row:\\n> description-2\",\n      \"short\": false,\n      \"color\": \"#36A64F\",\n      \"fields\": [\n        {\n          \"title\": \"Condition results\",\n          \"value\": \":white_check_mark: - `[CONNECTED] == true`\\n:white_check_mark: - `[STATUS] == 200`\\n\",\n          \"short\": false\n        }\n      ]\n    }\n  ]\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&scenario.Endpoint,
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example01.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getWebhookURLForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
 }

alerting/provider/teams/teams.go

@@ -1,12 +1,14 @@
 package teams
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using Teams
@@ -14,23 +16,59 @@ type AlertProvider struct {
 	WebhookURL string `yaml:"webhook-url"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group      string `yaml:"group"`
+	WebhookURL string `yaml:"webhook-url"`
 }
 
 // IsValid returns whether the provider's configuration is valid
 func (provider *AlertProvider) IsValid() bool {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if isAlreadyRegistered := registeredGroups[override.Group]; isAlreadyRegistered || override.Group == "" || len(override.WebhookURL) == 0 {
+				return false
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
 	return len(provider.WebhookURL) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
-	var message string
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
-	var color string
+	request, err := http.NewRequest(http.MethodPost, provider.getWebhookURLForGroup(endpoint.Group), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
+	var message, color string
 	if resolved {
-		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.Name, alert.SuccessThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been resolved after passing successfully %d time(s) in a row", endpoint.DisplayName(), alert.SuccessThreshold)
 		color = "#36A64F"
 	} else {
-		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been triggered due to having failed %d time(s) in a row", endpoint.DisplayName(), alert.FailureThreshold)
 		color = "#DD0000"
 	}
 	var results string
@@ -47,10 +85,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
 	if alertDescription := alert.GetDescription(); len(alertDescription) > 0 {
 		description = ":\\n> " + alertDescription
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{
-		URL:    provider.WebhookURL,
-		Method: http.MethodPost,
-		Body: fmt.Sprintf(`{
   "@type": "MessageCard",
   "@context": "http://schema.org/extensions",
   "themeColor": "%s",
@@ -66,9 +101,19 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
       "text": "%s"
     }
   ]
-}`, color, message, description, endpoint.URL, results),
+}`, color, message, description, endpoint.URL, results)
-		Headers: map[string]string{"Content-Type": "application/json"},
 }
+
+// getWebhookURLForGroup returns the appropriate Webhook URL integration to for a given group
+func (provider *AlertProvider) getWebhookURLForGroup(group string) string {
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				return override.WebhookURL
+			}
+		}
+	}
+	return provider.WebhookURL
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/teams/teams_test.go

@@ -3,14 +3,15 @@ package teams
 import (
 	"encoding/json"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
-func TestAlertProvider_IsValid(t *testing.T) {
+func TestAlertDefaultProvider_IsValid(t *testing.T) {
 	invalidProvider := AlertProvider{WebhookURL: ""}
 	if invalidProvider.IsValid() {
 		t.Error("provider shouldn't have been valid")
@@ -21,50 +22,237 @@ func TestAlertProvider_IsValid(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_IsValidWithOverride(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.org"}
+	providerWithInvalidOverrideGroup := AlertProvider{
-	alertDescription := "test"
+		Overrides: []Override{
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "svc"}, &alert.Alert{Description: &alertDescription}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+			{
-	if customAlertProvider == nil {
+				WebhookURL: "http://example.com",
-		t.Fatal("customAlertProvider shouldn't have been nil")
+				Group:      "",
+			},
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "resolved") {
+	if providerWithInvalidOverrideGroup.IsValid() {
-		t.Error("customAlertProvider.Body should've contained the substring resolved")
+		t.Error("provider Group shouldn't have been valid")
 	}
-	if customAlertProvider.URL != "http://example.org" {
+	providerWithInvalidOverrideTo := AlertProvider{
-		t.Errorf("expected URL to be %s, got %s", "http://example.org", customAlertProvider.URL)
+		Overrides: []Override{
+			{
+				WebhookURL: "",
+				Group:      "group",
+			},
+		},
 	}
-	if customAlertProvider.Method != http.MethodPost {
+	if providerWithInvalidOverrideTo.IsValid() {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
+		t.Error("provider integration key shouldn't have been valid")
 	}
-	body := make(map[string]interface{})
+	providerWithValidOverride := AlertProvider{
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+		WebhookURL: "http://example.com",
-	if err != nil {
+		Overrides: []Override{
-		t.Error("expected body to be valid JSON, got error:", err.Error())
+			{
+				WebhookURL: "http://example.com",
+				Group:      "group",
+			},
+		},
 	}
-	if expected := "An alert for *svc* has been resolved after passing successfully 0 time(s) in a row:\n> test"; expected != body["text"] {
+	if !providerWithValidOverride.IsValid() {
-		t.Errorf("expected $.text to be %s, got %s", expected, body["text"])
+		t.Error("provider should've been valid")
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{WebhookURL: "http://example.org"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if customAlertProvider.URL != "http://example.org" {
+			if !scenario.ExpectedError && err != nil {
-		t.Errorf("expected URL to be %s, got %s", "http://example.org", customAlertProvider.URL)
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.Method != http.MethodPost {
+		})
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
 	}
-	body := make(map[string]interface{})
+}
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
+
-	if err != nil {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
+	firstDescription := "description-1"
+	secondDescription := "description-2"
+	scenarios := []struct {
+		Name         string
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\n  \"@type\": \"MessageCard\",\n  \"@context\": \"http://schema.org/extensions\",\n  \"themeColor\": \"#DD0000\",\n  \"title\": \"&#x1F6A8; Gatus\",\n  \"text\": \"An alert for *endpoint-name* has been triggered due to having failed 3 time(s) in a row:\\n> description-1\",\n  \"sections\": [\n    {\n      \"activityTitle\": \"URL\",\n      \"text\": \"\"\n    },\n    {\n      \"activityTitle\": \"Condition results\",\n      \"text\": \"&#x274C; - `[CONNECTED] == true`<br/>&#x274C; - `[STATUS] == 200`<br/>\"\n    }\n  ]\n}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\n  \"@type\": \"MessageCard\",\n  \"@context\": \"http://schema.org/extensions\",\n  \"themeColor\": \"#36A64F\",\n  \"title\": \"&#x1F6A8; Gatus\",\n  \"text\": \"An alert for *endpoint-name* has been resolved after passing successfully 5 time(s) in a row:\\n> description-2\",\n  \"sections\": [\n    {\n      \"activityTitle\": \"URL\",\n      \"text\": \"\"\n    },\n    {\n      \"activityTitle\": \"Condition results\",\n      \"text\": \"&#x2705; - `[CONNECTED] == true`<br/>&#x2705; - `[STATUS] == 200`<br/>\"\n    }\n  ]\n}",
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
+			}
+			out := make(map[string]interface{})
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
+}
+
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
+		t.Error("expected default alert to be not nil")
+	}
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
+		t.Error("expected default alert to be nil")
+	}
+}
+
+func TestAlertProvider_getWebhookURLForGroup(t *testing.T) {
+	tests := []struct {
+		Name           string
+		Provider       AlertProvider
+		InputGroup     string
+		ExpectedOutput string
+	}{
+		{
+			Name: "provider-no-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-no-override-specify-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides:  nil,
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-no-group-should-default",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "",
+			ExpectedOutput: "http://example.com",
+		},
+		{
+			Name: "provider-with-override-specify-group-should-override",
+			Provider: AlertProvider{
+				WebhookURL: "http://example.com",
+				Overrides: []Override{
+					{
+						Group:      "group",
+						WebhookURL: "http://example01.com",
+					},
+				},
+			},
+			InputGroup:     "group",
+			ExpectedOutput: "http://example01.com",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if got := tt.Provider.getWebhookURLForGroup(tt.InputGroup); got != tt.ExpectedOutput {
+				t.Errorf("AlertProvider.getToForGroup() = %v, want %v", got, tt.ExpectedOutput)
+			}
+		})
+	}
 }

alerting/provider/telegram/telegram.go

@@ -1,35 +1,69 @@
 package telegram
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
+const defaultAPIURL = "https://api.telegram.org"
+
 // AlertProvider is the configuration necessary for sending an alert using Telegram
 type AlertProvider struct {
 	Token  string `yaml:"token"`
 	ID     string `yaml:"id"`
+	APIURL string `yaml:"api-url"`
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
 // IsValid returns whether the provider's configuration is valid
 func (provider *AlertProvider) IsValid() bool {
+	if provider.ClientConfig == nil {
+		provider.ClientConfig = client.GetDefaultConfig()
+	}
 	return len(provider.Token) > 0 && len(provider.ID) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	apiURL := provider.APIURL
+	if apiURL == "" {
+		apiURL = defaultAPIURL
+	}
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/bot%s/sendMessage", apiURL, provider.Token), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	response, err := client.GetHTTPClient(provider.ClientConfig).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
 	var message, results string
 	if resolved {
-		message = fmt.Sprintf("An alert for *%s* has been resolved:\\n—\\n    _healthcheck passing successfully %d time(s) in a row_\\n—  ", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been resolved:\\n—\\n    _healthcheck passing successfully %d time(s) in a row_\\n—  ", endpoint.DisplayName(), alert.FailureThreshold)
 	} else {
-		message = fmt.Sprintf("An alert for *%s* has been triggered:\\n—\\n    _healthcheck failed %d time(s) in a row_\\n—  ", endpoint.Name, alert.FailureThreshold)
+		message = fmt.Sprintf("An alert for *%s* has been triggered:\\n—\\n    _healthcheck failed %d time(s) in a row_\\n—  ", endpoint.DisplayName(), alert.FailureThreshold)
 	}
 	for _, conditionResult := range result.ConditionResults {
 		var prefix string
@@ -46,12 +80,7 @@ func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, al
 	} else {
 		text = fmt.Sprintf("⛑ *Gatus* \\n%s \\n*Condition results*\\n%s", message, results)
 	}
-	return &custom.AlertProvider{
+	return fmt.Sprintf(`{"chat_id": "%s", "text": "%s", "parse_mode": "MARKDOWN"}`, provider.ID, text)
-		URL:     fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token),
-		Method:  http.MethodPost,
-		Body:    fmt.Sprintf(`{"chat_id": "%s", "text": "%s", "parse_mode": "MARKDOWN"}`, provider.ID, text),
-		Headers: map[string]string{"Content-Type": "application/json"},
-	}
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/telegram/telegram_test.go

@@ -2,90 +2,167 @@ package telegram
 
 import (
 	"encoding/json"
-	"fmt"
 	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestAlertProvider_IsValid(t *testing.T) {
+	t.Run("invalid-provider", func(t *testing.T) {
 		invalidProvider := AlertProvider{Token: "", ID: ""}
 		if invalidProvider.IsValid() {
 			t.Error("provider shouldn't have been valid")
 		}
+	})
+	t.Run("valid-provider", func(t *testing.T) {
 		validProvider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}
+		if validProvider.ClientConfig != nil {
+			t.Error("provider client config should have been nil prior to IsValid() being executed")
+		}
 		if !validProvider.IsValid() {
 			t.Error("provider should've been valid")
 		}
+		if validProvider.ClientConfig == nil {
+			t.Error("provider client config should have been set after IsValid() was executed")
+		}
+	})
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_Send(t *testing.T) {
-	provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "12345678"}
+	defer client.InjectHTTPClient(nil)
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "SUCCESSFUL_CONDITION", Success: true}}}, true)
+	firstDescription := "description-1"
-	if customAlertProvider == nil {
+	secondDescription := "description-2"
-		t.Fatal("customAlertProvider shouldn't have been nil")
+	scenarios := []struct {
+		Name             string
+		Provider         AlertProvider
+		Alert            alert.Alert
+		Resolved         bool
+		MockRoundTripper test.MockRoundTripper
+		ExpectedError    bool
+	}{
+		{
+			Name:     "triggered",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "triggered-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: false,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
+		{
+			Name:     "resolved",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+			ExpectedError: false,
+		},
+		{
+			Name:     "resolved-error",
+			Provider: AlertProvider{},
+			Alert:    alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved: true,
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusInternalServerError, Body: http.NoBody}
+			}),
+			ExpectedError: true,
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "resolved") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring resolved")
+		t.Run(scenario.Name, func(t *testing.T) {
+			client.InjectHTTPClient(&http.Client{Transport: scenario.MockRoundTripper})
+			err := scenario.Provider.Send(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if scenario.ExpectedError && err == nil {
+				t.Error("expected error, got none")
 			}
-	if customAlertProvider.URL != fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token) {
+			if !scenario.ExpectedError && err != nil {
-		t.Errorf("expected URL to be %s, got %s", fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token), customAlertProvider.URL)
+				t.Error("expected no error, got", err.Error())
 			}
-	if customAlertProvider.Method != http.MethodPost {
+		})
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	//_, err := json.Marshal(customAlertProvider.Body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
-	provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "0123456789"}
+	firstDescription := "description-1"
-	description := "Healthcheck Successful"
+	secondDescription := "description-2"
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{Description: &description}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+	scenarios := []struct {
-	if customAlertProvider == nil {
+		Name         string
-		t.Fatal("customAlertProvider shouldn't have been nil")
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{ID: "123"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "{\"chat_id\": \"123\", \"text\": \"⛑ *Gatus* \\nAn alert for *endpoint-name* has been triggered:\\n—\\n    _healthcheck failed 3 time(s) in a row_\\n—   \\n*Description* \\n_description-1_  \\n\\n*Condition results*\\n❌ - `[CONNECTED] == true`\\n❌ - `[STATUS] == 200`\\n\", \"parse_mode\": \"MARKDOWN\"}",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{ID: "123"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "{\"chat_id\": \"123\", \"text\": \"⛑ *Gatus* \\nAn alert for *endpoint-name* has been resolved:\\n—\\n    _healthcheck passing successfully 3 time(s) in a row_\\n—   \\n*Description* \\n_description-2_  \\n\\n*Condition results*\\n✅ - `[CONNECTED] == true`\\n✅ - `[STATUS] == 200`\\n\", \"parse_mode\": \"MARKDOWN\"}",
+		},
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	for _, scenario := range scenarios {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Run(scenario.Name, func(t *testing.T) {
+			body := scenario.Provider.buildRequestBody(
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
 			}
-	if customAlertProvider.URL != fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token) {
+			out := make(map[string]interface{})
-		t.Errorf("expected URL to be %s, got %s", fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token), customAlertProvider.URL)
+			if err := json.Unmarshal([]byte(body), &out); err != nil {
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
 				t.Error("expected body to be valid JSON, got error:", err.Error())
 			}
+		})
+	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithDescription(t *testing.T) {
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
-	provider := AlertProvider{Token: "123456:ABC-DEF1234ghIkl-zyx57W2v1u123ew11", ID: "0123456789"}
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{}, &alert.Alert{}, &core.Result{ConditionResults: []*core.ConditionResult{{Condition: "UNSUCCESSFUL_CONDITION", Success: false}}}, false)
+		t.Error("expected default alert to be not nil")
-	if customAlertProvider == nil {
-		t.Fatal("customAlertProvider shouldn't have been nil")
 	}
-	if !strings.Contains(customAlertProvider.Body, "triggered") {
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
-		t.Error("customAlertProvider.Body should've contained the substring triggered")
+		t.Error("expected default alert to be nil")
-	}
-	if customAlertProvider.URL != fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token) {
-		t.Errorf("expected URL to be %s, got %s", fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", provider.Token), customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	body := make(map[string]interface{})
-	err := json.Unmarshal([]byte(customAlertProvider.Body), &body)
-	if err != nil {
-		t.Error("expected body to be valid JSON, got error:", err.Error())
 	}
 }

alerting/provider/twilio/twilio.go

@@ -1,14 +1,16 @@
 package twilio
 
 import (
+	"bytes"
 	"encoding/base64"
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 // AlertProvider is the configuration necessary for sending an alert using Twilio
@@ -19,7 +21,7 @@ type AlertProvider struct {
 	To    string `yaml:"to"`
 
 	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
-	DefaultAlert *alert.Alert `yaml:"default-alert"`
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
 }
 
 // IsValid returns whether the provider's configuration is valid
@@ -27,27 +29,39 @@ func (provider *AlertProvider) IsValid() bool {
 	return len(provider.Token) > 0 && len(provider.SID) > 0 && len(provider.From) > 0 && len(provider.To) > 0
 }
 
-// ToCustomAlertProvider converts the provider into a custom.AlertProvider
+// Send an alert using the provider
-func (provider *AlertProvider) ToCustomAlertProvider(endpoint *core.Endpoint, alert *alert.Alert, _ *core.Result, resolved bool) *custom.AlertProvider {
+func (provider *AlertProvider) Send(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) error {
+	buffer := bytes.NewBuffer([]byte(provider.buildRequestBody(endpoint, alert, result, resolved)))
+	request, err := http.NewRequest(http.MethodPost, fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json", provider.SID), buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	request.Header.Set("Authorization", fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(provider.SID+":"+provider.Token))))
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(endpoint *core.Endpoint, alert *alert.Alert, result *core.Result, resolved bool) string {
 	var message string
 	if resolved {
-		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("RESOLVED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
 	} else {
-		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.Name, alert.GetDescription())
+		message = fmt.Sprintf("TRIGGERED: %s - %s", endpoint.DisplayName(), alert.GetDescription())
 	}
-	return &custom.AlertProvider{
+	return url.Values{
-		URL:    fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json", provider.SID),
-		Method: http.MethodPost,
-		Body: url.Values{
 		"To":   {provider.To},
 		"From": {provider.From},
 		"Body": {message},
-		}.Encode(),
+	}.Encode()
-		Headers: map[string]string{
-			"Content-Type":  "application/x-www-form-urlencoded",
-			"Authorization": fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf("%s:%s", provider.SID, provider.Token)))),
-		},
-	}
 }
 
 // GetDefaultAlert returns the provider's default alert configuration

alerting/provider/twilio/twilio_test.go

@@ -1,12 +1,10 @@
 package twilio
 
 import (
-	"net/http"
-	"strings"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 func TestTwilioAlertProvider_IsValid(t *testing.T) {
@@ -25,54 +23,56 @@ func TestTwilioAlertProvider_IsValid(t *testing.T) {
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithResolvedAlert(t *testing.T) {
+func TestAlertProvider_buildRequestBody(t *testing.T) {
-	provider := AlertProvider{
+	firstDescription := "description-1"
-		SID:   "1",
+	secondDescription := "description-2"
-		Token: "2",
+	scenarios := []struct {
-		From:  "3",
+		Name         string
-		To:    "4",
+		Provider     AlertProvider
+		Alert        alert.Alert
+		Resolved     bool
+		ExpectedBody string
+	}{
+		{
+			Name:         "triggered",
+			Provider:     AlertProvider{SID: "1", Token: "2", From: "3", To: "4"},
+			Alert:        alert.Alert{Description: &firstDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     false,
+			ExpectedBody: "Body=TRIGGERED%3A+endpoint-name+-+description-1&From=3&To=4",
+		},
+		{
+			Name:         "resolved",
+			Provider:     AlertProvider{SID: "1", Token: "2", From: "3", To: "4"},
+			Alert:        alert.Alert{Description: &secondDescription, SuccessThreshold: 5, FailureThreshold: 3},
+			Resolved:     true,
+			ExpectedBody: "Body=RESOLVED%3A+endpoint-name+-+description-2&From=3&To=4",
+		},
 	}
-	description := "alert-description"
+	for _, scenario := range scenarios {
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "endpoint-name"}, &alert.Alert{Description: &description}, &core.Result{}, true)
+		t.Run(scenario.Name, func(t *testing.T) {
-	if customAlertProvider == nil {
+			body := scenario.Provider.buildRequestBody(
-		t.Fatal("customAlertProvider shouldn't have been nil")
+				&core.Endpoint{Name: "endpoint-name"},
+				&scenario.Alert,
+				&core.Result{
+					ConditionResults: []*core.ConditionResult{
+						{Condition: "[CONNECTED] == true", Success: scenario.Resolved},
+						{Condition: "[STATUS] == 200", Success: scenario.Resolved},
+					},
+				},
+				scenario.Resolved,
+			)
+			if body != scenario.ExpectedBody {
+				t.Errorf("expected %s, got %s", scenario.ExpectedBody, body)
 			}
-	if !strings.Contains(customAlertProvider.Body, "RESOLVED") {
+		})
-		t.Error("customAlertProvider.Body should've contained the substring RESOLVED")
-	}
-	if customAlertProvider.URL != "https://api.twilio.com/2010-04-01/Accounts/1/Messages.json" {
-		t.Errorf("expected URL to be %s, got %s", "https://api.twilio.com/2010-04-01/Accounts/1/Messages.json", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	if customAlertProvider.Body != "Body=RESOLVED%3A+endpoint-name+-+alert-description&From=3&To=4" {
-		t.Errorf("expected body to be %s, got %s", "Body=RESOLVED%3A+endpoint-name+-+alert-description&From=3&To=4", customAlertProvider.Body)
 	}
 }
 
-func TestAlertProvider_ToCustomAlertProviderWithTriggeredAlert(t *testing.T) {
+func TestAlertProvider_GetDefaultAlert(t *testing.T) {
-	provider := AlertProvider{
+	if (AlertProvider{DefaultAlert: &alert.Alert{}}).GetDefaultAlert() == nil {
-		SID:   "4",
+		t.Error("expected default alert to be not nil")
-		Token: "3",
-		From:  "2",
-		To:    "1",
 	}
-	description := "alert-description"
+	if (AlertProvider{DefaultAlert: nil}).GetDefaultAlert() != nil {
-	customAlertProvider := provider.ToCustomAlertProvider(&core.Endpoint{Name: "endpoint-name"}, &alert.Alert{Description: &description}, &core.Result{}, false)
+		t.Error("expected default alert to be nil")
-	if customAlertProvider == nil {
-		t.Fatal("customAlertProvider shouldn't have been nil")
-	}
-	if !strings.Contains(customAlertProvider.Body, "TRIGGERED") {
-		t.Error("customAlertProvider.Body should've contained the substring TRIGGERED")
-	}
-	if customAlertProvider.URL != "https://api.twilio.com/2010-04-01/Accounts/4/Messages.json" {
-		t.Errorf("expected URL to be %s, got %s", "https://api.twilio.com/2010-04-01/Accounts/4/Messages.json", customAlertProvider.URL)
-	}
-	if customAlertProvider.Method != http.MethodPost {
-		t.Errorf("expected method to be %s, got %s", http.MethodPost, customAlertProvider.Method)
-	}
-	if customAlertProvider.Body != "Body=TRIGGERED%3A+endpoint-name+-+alert-description&From=2&To=1" {
-		t.Errorf("expected body to be %s, got %s", "Body=TRIGGERED%3A+endpoint-name+-+alert-description&From=2&To=1", customAlertProvider.Body)
 	}
 }

client/client.go

@@ -14,8 +14,14 @@ import (
 	"github.com/go-ping/ping"
 )
 
-// GetHTTPClient returns the shared HTTP client
+// injectedHTTPClient is used for testing purposes
+var injectedHTTPClient *http.Client
+
+// GetHTTPClient returns the shared HTTP client, or the client from the configuration passed
 func GetHTTPClient(config *Config) *http.Client {
+	if injectedHTTPClient != nil {
+		return injectedHTTPClient
+	}
 	if config == nil {
 		return defaultConfig.getHTTPClient()
 	}
@@ -104,3 +110,8 @@ func Ping(address string, config *Config) (bool, time.Duration) {
 	}
 	return true, 0
 }
+
+// InjectHTTPClient is used to inject a custom HTTP client for testing purposes
+func InjectHTTPClient(httpClient *http.Client) {
+	injectedHTTPClient = httpClient
+}

client/client_test.go

@@ -1,8 +1,13 @@
 package client
 
 import (
+	"bytes"
+	"io"
+	"net/http"
 	"testing"
 	"time"
+
+	"github.com/TwiN/gatus/v4/test"
 )
 
 func TestGetHTTPClient(t *testing.T) {
@@ -10,8 +15,18 @@ func TestGetHTTPClient(t *testing.T) {
 		Insecure:       false,
 		IgnoreRedirect: false,
 		Timeout:        0,
+		DNSResolver:    "tcp://1.1.1.1:53",
+		OAuth2Config: &OAuth2Config{
+			ClientID:     "00000000-0000-0000-0000-000000000000",
+			ClientSecret: "secretsauce",
+			TokenURL:     "https://token-server.local/token",
+			Scopes:       []string{"https://application.local/.default"},
+		},
+	}
+	err := cfg.ValidateAndSetDefaults()
+	if err != nil {
+		t.Errorf("expected error to be nil, but got: `%s`", err)
 	}
-	cfg.ValidateAndSetDefaults()
 	if GetHTTPClient(cfg) == nil {
 		t.Error("expected client to not be nil")
 	}
@@ -146,3 +161,61 @@ func TestCanCreateTCPConnection(t *testing.T) {
 		t.Error("should've failed, because there's no port in the address")
 	}
 }
+
+// This test checks if a HTTP client configured with `configureOAuth2()` automatically
+// performs a Client Credentials OAuth2 flow and adds the obtained token as a `Authorization`
+// header to all outgoing HTTP calls.
+func TestHttpClientProvidesOAuth2BearerToken(t *testing.T) {
+	defer InjectHTTPClient(nil)
+	oAuth2Config := &OAuth2Config{
+		ClientID:     "00000000-0000-0000-0000-000000000000",
+		ClientSecret: "secretsauce",
+		TokenURL:     "https://token-server.local/token",
+		Scopes:       []string{"https://application.local/.default"},
+	}
+	mockHttpClient := &http.Client{
+		Transport: test.MockRoundTripper(func(r *http.Request) *http.Response {
+			// if the mock HTTP client tries to get a token from the `token-server`
+			// we provide the expected token response
+			if r.Host == "token-server.local" {
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body: io.NopCloser(bytes.NewReader(
+						[]byte(
+							`{"token_type":"Bearer","expires_in":3599,"ext_expires_in":3599,"access_token":"secret-token"}`,
+						),
+					)),
+				}
+			}
+			// to verify the headers were sent as expected, we echo them back in the
+			// `X-Org-Authorization` header and check if the token value matches our
+			// mocked `token-server` response
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Header: map[string][]string{
+					"X-Org-Authorization": {r.Header.Get("Authorization")},
+				},
+				Body: http.NoBody,
+			}
+		}),
+	}
+	mockHttpClientWithOAuth := configureOAuth2(mockHttpClient, *oAuth2Config)
+	InjectHTTPClient(mockHttpClientWithOAuth)
+	request, err := http.NewRequest(http.MethodPost, "http://127.0.0.1:8282", http.NoBody)
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	response, err := mockHttpClientWithOAuth.Do(request)
+	if err != nil {
+		t.Error("expected no error, got", err.Error())
+	}
+	if response.Header == nil {
+		t.Error("expected response headers, but got nil")
+	}
+	// the mock response echos the Authorization header used in the request back
+	// to us as `X-Org-Authorization` header, we check here if the value matches
+	// our expected token `secret-token`
+	if response.Header.Get("X-Org-Authorization") != "Bearer secret-token" {
+		t.Error("exptected `secret-token` as Bearer token in the mocked response header `X-Org-Authorization`, but got", response.Header.Get("X-Org-Authorization"))
+	}
+}

client/config.go

@@ -1,9 +1,18 @@
 package client
 
 import (
+	"context"
 	"crypto/tls"
+	"errors"
+	"log"
+	"net"
 	"net/http"
+	"regexp"
+	"strconv"
 	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/clientcredentials"
 )
 
 const (
@@ -11,7 +20,10 @@ const (
 )
 
 var (
-	// DefaultConfig is the default client configuration
+	ErrInvalidDNSResolver        = errors.New("invalid DNS resolver specified. Required format is {proto}://{ip}:{port}")
+	ErrInvalidDNSResolverPort    = errors.New("invalid DNS resolver port")
+	ErrInvalidClientOAuth2Config = errors.New("invalid OAuth2 configuration, all fields are required")
+
 	defaultConfig = Config{
 		Insecure:       false,
 		IgnoreRedirect: false,
@@ -28,22 +40,99 @@ func GetDefaultConfig() *Config {
 // Config is the configuration for clients
 type Config struct {
 	// Insecure determines whether to skip verifying the server's certificate chain and host name
-	Insecure bool `yaml:"insecure"`
+	Insecure bool `yaml:"insecure,omitempty"`
 
 	// IgnoreRedirect determines whether to ignore redirects (true) or follow them (false, default)
-	IgnoreRedirect bool `yaml:"ignore-redirect"`
+	IgnoreRedirect bool `yaml:"ignore-redirect,omitempty"`
 
 	// Timeout for the client
 	Timeout time.Duration `yaml:"timeout"`
 
+	// DNSResolver override for the HTTP client
+	// Expected format is {protocol}://{host}:{port}, e.g. tcp://1.1.1.1:53
+	DNSResolver string `yaml:"dns-resolver,omitempty"`
+
+	// OAuth2Config is the OAuth2 configuration used for the client.
+	//
+	// If non-nil, the http.Client returned by getHTTPClient will automatically retrieve a token if necessary.
+	// See configureOAuth2 for more details.
+	OAuth2Config *OAuth2Config `yaml:"oauth2,omitempty"`
+
 	httpClient *http.Client
 }
 
+// DNSResolverConfig is the parsed configuration from the DNSResolver config string.
+type DNSResolverConfig struct {
+	Protocol string
+	Host     string
+	Port     string
+}
+
+// OAuth2Config is the configuration for the OAuth2 client credentials flow
+type OAuth2Config struct {
+	TokenURL     string   `yaml:"token-url"` // e.g. https://dev-12345678.okta.com/token
+	ClientID     string   `yaml:"client-id"`
+	ClientSecret string   `yaml:"client-secret"`
+	Scopes       []string `yaml:"scopes"` // e.g. ["openid"]
+}
+
 // ValidateAndSetDefaults validates the client configuration and sets the default values if necessary
-func (c *Config) ValidateAndSetDefaults() {
+func (c *Config) ValidateAndSetDefaults() error {
 	if c.Timeout < time.Millisecond {
 		c.Timeout = 10 * time.Second
 	}
+	if c.HasCustomDNSResolver() {
+		// Validate the DNS resolver now to make sure it will not return an error later.
+		if _, err := c.parseDNSResolver(); err != nil {
+			return err
+		}
+	}
+	if c.HasOAuth2Config() && !c.OAuth2Config.isValid() {
+		return ErrInvalidClientOAuth2Config
+	}
+	return nil
+}
+
+// HasCustomDNSResolver returns whether a custom DNSResolver is configured
+func (c *Config) HasCustomDNSResolver() bool {
+	return len(c.DNSResolver) > 0
+}
+
+// parseDNSResolver parses the DNS resolver into the DNSResolverConfig struct
+func (c *Config) parseDNSResolver() (*DNSResolverConfig, error) {
+	re := regexp.MustCompile(`^(?P<proto>(.*))://(?P<host>[A-Za-z0-9\-\.]+):(?P<port>[0-9]+)?(.*)$`)
+	matches := re.FindStringSubmatch(c.DNSResolver)
+	if len(matches) == 0 {
+		return nil, ErrInvalidDNSResolver
+	}
+	r := make(map[string]string)
+	for i, k := range re.SubexpNames() {
+		if i != 0 && k != "" {
+			r[k] = matches[i]
+		}
+	}
+	port, err := strconv.Atoi(r["port"])
+	if err != nil {
+		return nil, err
+	}
+	if port < 1 || port > 65535 {
+		return nil, ErrInvalidDNSResolverPort
+	}
+	return &DNSResolverConfig{
+		Protocol: r["proto"],
+		Host:     r["host"],
+		Port:     r["port"],
+	}, nil
+}
+
+// HasOAuth2Config returns true if the client has OAuth2 configuration parameters
+func (c *Config) HasOAuth2Config() bool {
+	return c.OAuth2Config != nil
+}
+
+// isValid() returns true if the OAuth2 configuration is valid
+func (c *OAuth2Config) isValid() bool {
+	return len(c.TokenURL) > 0 && len(c.ClientID) > 0 && len(c.ClientSecret) > 0 && len(c.Scopes) > 0
 }
 
 // GetHTTPClient return an HTTP client matching the Config's parameters.
@@ -68,6 +157,43 @@ func (c *Config) getHTTPClient() *http.Client {
 				return nil
 			},
 		}
+		if c.HasCustomDNSResolver() {
+			dnsResolver, err := c.parseDNSResolver()
+			if err != nil {
+				// We're ignoring the error, because it should have been validated on startup ValidateAndSetDefaults.
+				// It shouldn't happen, but if it does, we'll log it... Better safe than sorry ;)
+				log.Println("[client][getHTTPClient] THIS SHOULD NOT HAPPEN. Silently ignoring invalid DNS resolver due to error:", err.Error())
+			} else {
+				dialer := &net.Dialer{
+					Resolver: &net.Resolver{
+						PreferGo: true,
+						Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+							d := net.Dialer{}
+							return d.DialContext(ctx, dnsResolver.Protocol, dnsResolver.Host+":"+dnsResolver.Port)
+						},
+					},
+				}
+				c.httpClient.Transport.(*http.Transport).DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+					return dialer.DialContext(ctx, network, addr)
+				}
+			}
+		}
+		if c.HasOAuth2Config() {
+			c.httpClient = configureOAuth2(c.httpClient, *c.OAuth2Config)
+		}
 	}
 	return c.httpClient
 }
+
+// configureOAuth2 returns an HTTP client that will obtain and refresh tokens as necessary.
+// The returned Client and its Transport should not be modified.
+func configureOAuth2(httpClient *http.Client, c OAuth2Config) *http.Client {
+	oauth2cfg := clientcredentials.Config{
+		ClientID:     c.ClientID,
+		ClientSecret: c.ClientSecret,
+		Scopes:       c.Scopes,
+		TokenURL:     c.TokenURL,
+	}
+	ctx := context.WithValue(context.Background(), oauth2.HTTPClient, httpClient)
+	return oauth2cfg.Client(ctx)
+}

client/config_test.go

@@ -35,3 +35,47 @@ func TestConfig_getHTTPClient(t *testing.T) {
 		t.Error("expected Config.IgnoreRedirect set to true to cause the HTTP client's CheckRedirect to return http.ErrUseLastResponse")
 	}
 }
+
+func TestConfig_ValidateAndSetDefaults_withCustomDNSResolver(t *testing.T) {
+	type args struct {
+		dnsResolver string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "with-valid-resolver",
+			args: args{
+				dnsResolver: "tcp://1.1.1.1:53",
+			},
+			wantErr: false,
+		},
+		{
+			name: "with-invalid-resolver-port",
+			args: args{
+				dnsResolver: "tcp://127.0.0.1:99999",
+			},
+			wantErr: true,
+		},
+		{
+			name: "with-invalid-resolver-format",
+			args: args{
+				dnsResolver: "foobar",
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := &Config{
+				DNSResolver: tt.args.dnsResolver,
+			}
+			err := cfg.ValidateAndSetDefaults()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ValidateAndSetDefaults() error=%v, wantErr=%v", err, tt.wantErr)
+			}
+		})
+	}
+}

config.yaml

@@ -31,7 +31,7 @@ endpoints:
       - "[STATUS] == 200"
 
   - name: example-dns-query
-    url: "8.8.8.8" # Address of the DNS server to use
+    url: "1.1.1.1" # Address of the DNS server to use
     interval: 5m
     dns:
       query-name: "example.com"
@@ -45,3 +45,9 @@ endpoints:
     interval: 1m
     conditions:
       - "[CONNECTED] == true"
+
+  - name: check-domain-expiration
+    url: "https://example.org/"
+    interval: 1h
+    conditions:
+      - "[DOMAIN_EXPIRATION] > 720h"

config/config.go

@@ -2,20 +2,22 @@ package config
 
 import (
 	"errors"
-	"io/ioutil"
+	"fmt"
 	"log"
 	"os"
 	"time"
 
-	"github.com/TwiN/gatus/v3/alerting"
+	"github.com/TwiN/gatus/v4/alerting"
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider"
+	"github.com/TwiN/gatus/v4/alerting/provider"
-	"github.com/TwiN/gatus/v3/config/maintenance"
+	"github.com/TwiN/gatus/v4/config/maintenance"
-	"github.com/TwiN/gatus/v3/config/ui"
+	"github.com/TwiN/gatus/v4/config/remote"
-	"github.com/TwiN/gatus/v3/config/web"
+	"github.com/TwiN/gatus/v4/config/ui"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/config/web"
-	"github.com/TwiN/gatus/v3/security"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/storage"
+	"github.com/TwiN/gatus/v4/security"
+	"github.com/TwiN/gatus/v4/storage"
+	"github.com/TwiN/gatus/v4/util"
 	"gopkg.in/yaml.v2"
 )
 
@@ -86,10 +88,24 @@ type Config struct {
 	// Maintenance is the configuration for creating a maintenance window in which no alerts are sent
 	Maintenance *maintenance.Config `yaml:"maintenance,omitempty"`
 
+	// Remote is the configuration for remote Gatus instances
+	// WARNING: This is in ALPHA and may change or be completely removed in the future
+	Remote *remote.Config `yaml:"remote,omitempty"`
+
 	filePath        string    // path to the file from which config was loaded from
 	lastFileModTime time.Time // last modification time
 }
 
+func (config *Config) GetEndpointByKey(key string) *core.Endpoint {
+	for i := 0; i < len(config.Endpoints); i++ {
+		ep := config.Endpoints[i]
+		if util.ConvertGroupAndEndpointNameToKey(ep.Group, ep.Name) == key {
+			return ep
+		}
+	}
+	return nil
+}
+
 // HasLoadedConfigurationFileBeenModified returns whether the file that the
 // configuration has been loaded from has been modified since it was last read
 func (config Config) HasLoadedConfigurationFileBeenModified() bool {
@@ -142,7 +158,7 @@ func LoadDefaultConfiguration() (*Config, error) {
 
 func readConfigurationFile(fileName string) (config *Config, err error) {
 	var bytes []byte
-	if bytes, err = ioutil.ReadFile(fileName); err == nil {
+	if bytes, err = os.ReadFile(fileName); err == nil {
 		// file exists, so we'll parse it and return it
 		return parseAndValidateConfigBytes(bytes)
 	}
@@ -186,10 +202,22 @@ func parseAndValidateConfigBytes(yamlBytes []byte) (config *Config, err error) {
 		if err := validateStorageConfig(config); err != nil {
 			return nil, err
 		}
+		if err := validateRemoteConfig(config); err != nil {
+			return nil, err
+		}
 	}
 	return
 }
 
+func validateRemoteConfig(config *Config) error {
+	if config.Remote != nil {
+		if err := config.Remote.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func validateStorageConfig(config *Config) error {
 	if config.Storage == nil {
 		config.Storage = &storage.Config{
@@ -240,7 +268,7 @@ func validateEndpointsConfig(config *Config) error {
 			log.Printf("[config][validateEndpointsConfig] Validating endpoint '%s'", endpoint.Name)
 		}
 		if err := endpoint.ValidateAndSetDefaults(); err != nil {
-			return err
+			return fmt.Errorf("invalid endpoint %s: %s", endpoint.DisplayName(), err)
 		}
 	}
 	log.Printf("[config][validateEndpointsConfig] Validated %d endpoints", len(config.Endpoints))
@@ -274,8 +302,13 @@ func validateAlertingConfig(alertingConfig *alerting.Config, endpoints []*core.E
 	alertTypes := []alert.Type{
 		alert.TypeCustom,
 		alert.TypeDiscord,
+		alert.TypeGoogleChat,
+		alert.TypeEmail,
+		alert.TypeMatrix,
 		alert.TypeMattermost,
 		alert.TypeMessagebird,
+		alert.TypeNtfy,
+		alert.TypeOpsgenie,
 		alert.TypePagerDuty,
 		alert.TypeSlack,
 		alert.TypeTeams,

config/config_test.go

@@ -5,22 +5,21 @@ import (
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/alerting"
+	"github.com/TwiN/gatus/v4/alerting"
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/alerting/provider/custom"
+	"github.com/TwiN/gatus/v4/alerting/provider/custom"
-	"github.com/TwiN/gatus/v3/alerting/provider/discord"
+	"github.com/TwiN/gatus/v4/alerting/provider/discord"
-	"github.com/TwiN/gatus/v3/alerting/provider/mattermost"
+	"github.com/TwiN/gatus/v4/alerting/provider/mattermost"
-	"github.com/TwiN/gatus/v3/alerting/provider/messagebird"
+	"github.com/TwiN/gatus/v4/alerting/provider/messagebird"
-	"github.com/TwiN/gatus/v3/alerting/provider/pagerduty"
+	"github.com/TwiN/gatus/v4/alerting/provider/pagerduty"
-	"github.com/TwiN/gatus/v3/alerting/provider/slack"
+	"github.com/TwiN/gatus/v4/alerting/provider/slack"
-	"github.com/TwiN/gatus/v3/alerting/provider/teams"
+	"github.com/TwiN/gatus/v4/alerting/provider/teams"
-	"github.com/TwiN/gatus/v3/alerting/provider/telegram"
+	"github.com/TwiN/gatus/v4/alerting/provider/telegram"
-	"github.com/TwiN/gatus/v3/alerting/provider/twilio"
+	"github.com/TwiN/gatus/v4/alerting/provider/twilio"
-	"github.com/TwiN/gatus/v3/client"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/config/ui"
+	"github.com/TwiN/gatus/v4/config/web"
-	"github.com/TwiN/gatus/v3/config/web"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/storage"
-	"github.com/TwiN/gatus/v3/storage"
 )
 
 func TestLoadFileThatDoesNotExist(t *testing.T) {
@@ -39,10 +38,6 @@ func TestLoadDefaultConfigurationFile(t *testing.T) {
 
 func TestParseAndValidateConfigBytes(t *testing.T) {
 	file := t.TempDir() + "/test.db"
-	ui.StaticFolder = "../web/static"
-	defer func() {
-		ui.StaticFolder = "./web/static"
-	}()
 	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
 storage:
   type: sqlite
@@ -53,7 +48,14 @@ maintenance:
   duration: 4h
   every: [Monday, Thursday]
 ui:
-  title: Test
+  title: T
+  header: H
+  link: https://example.org
+  buttons:
+    - name: "Home"
+      link: "https://example.org"
+    - name: "Status page"
+      link: "https://status.example.org"
 endpoints:
   - name: website
     url: https://twin.sh/health
@@ -88,8 +90,8 @@ endpoints:
 	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeSQLite {
 		t.Error("expected storage to be set to sqlite, got", config.Storage)
 	}
-	if config.UI == nil || config.UI.Title != "Test" {
+	if config.UI == nil || config.UI.Title != "T" || config.UI.Header != "H" || config.UI.Link != "https://example.org" || len(config.UI.Buttons) != 2 || config.UI.Buttons[0].Name != "Home" || config.UI.Buttons[0].Link != "https://example.org" || config.UI.Buttons[1].Name != "Status page" || config.UI.Buttons[1].Link != "https://status.example.org" {
-		t.Error("Expected Config.UI.Title to be Test")
+		t.Error("expected ui to be set to T, H, https://example.org, 2 buttons, Home and Status page, got", config.UI)
 	}
 	if mc := config.Maintenance; mc == nil || mc.Start != "00:00" || !mc.IsEnabled() || mc.Duration != 4*time.Hour || len(mc.Every) != 2 {
 		t.Error("Expected Config.Maintenance to be configured properly")
@@ -1118,7 +1120,7 @@ endpoints:
     conditions:
       - "[STATUS] == 200"
 `))
-	if err != core.ErrEndpointWithNoName {
+	if err == nil {
 		t.Error("should've returned an error")
 	}
 }
@@ -1172,12 +1174,12 @@ endpoints:
 
 func TestParseAndValidateConfigBytesWithValidSecurityConfig(t *testing.T) {
 	const expectedUsername = "admin"
-	const expectedPasswordHash = "6b97ed68d14eb3f1aa959ce5d49c7dc612e1eb1dafd73b1e705847483fd6a6c809f2ceb4e8df6ff9984c6298ff0285cace6614bf8daa9f0070101b6c89899e22"
+	const expectedPasswordHash = "JDJhJDEwJHRiMnRFakxWazZLdXBzRERQazB1TE8vckRLY05Yb1hSdnoxWU0yQ1FaYXZRSW1McmladDYu"
 	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`debug: true
 security:
   basic:
     username: "%s"
-    password-sha512: "%s"
+    password-bcrypt-base64: "%s"
 endpoints:
   - name: website
     url: https://twin.sh/health
@@ -1202,8 +1204,8 @@ endpoints:
 	if config.Security.Basic.Username != expectedUsername {
 		t.Errorf("config.Security.Basic.Username should've been %s, but was %s", expectedUsername, config.Security.Basic.Username)
 	}
-	if config.Security.Basic.PasswordSha512Hash != expectedPasswordHash {
+	if config.Security.Basic.PasswordBcryptHashBase64Encoded != expectedPasswordHash {
-		t.Errorf("config.Security.Basic.PasswordSha512Hash should've been %s, but was %s", expectedPasswordHash, config.Security.Basic.PasswordSha512Hash)
+		t.Errorf("config.Security.Basic.PasswordBcryptHashBase64Encoded should've been %s, but was %s", expectedPasswordHash, config.Security.Basic.PasswordBcryptHashBase64Encoded)
 	}
 }
 
@@ -1302,53 +1304,3 @@ endpoints:
 		t.Error("services should've been merged in endpoints")
 	}
 }
-
-// XXX: Remove this in v4.0.0
-func TestParseAndValidateConfigBytes_backwardCompatibleWithStorageFile(t *testing.T) {
-	file := t.TempDir() + "/test.db"
-	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
-storage:
-  type: sqlite
-  file: %s
-
-endpoints:
-  - name: website
-    url: https://twin.sh/actuator/health
-    conditions:
-      - "[STATUS] == 200"
-`, file)))
-	if err != nil {
-		t.Error("expected no error, got", err.Error())
-	}
-	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
-	}
-	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeSQLite {
-		t.Error("expected storage to be set to sqlite, got", config.Storage)
-	}
-}
-
-// XXX: Remove this in v4.0.0
-func TestParseAndValidateConfigBytes_backwardCompatibleWithStorageTypeMemoryAndFile(t *testing.T) {
-	file := t.TempDir() + "/test.db"
-	config, err := parseAndValidateConfigBytes([]byte(fmt.Sprintf(`
-storage:
-  type: memory
-  file: %s
-
-endpoints:
-  - name: website
-    url: https://twin.sh/actuator/health
-    conditions:
-      - "[STATUS] == 200"
-`, file)))
-	if err != nil {
-		t.Error("expected no error, got", err.Error())
-	}
-	if config == nil {
-		t.Fatal("Config shouldn't have been nil")
-	}
-	if config.Storage == nil || config.Storage.Path != file || config.Storage.Type != storage.TypeMemory {
-		t.Error("expected storage to be set to memory, got", config.Storage)
-	}
-}

config/maintenance/maintenance.go

@@ -39,7 +39,6 @@ type Config struct {
 	Every []string `yaml:"every"`
 
 	durationToStartFromMidnight time.Duration
-	timeLocation                *time.Location
 }
 
 func GetDefaultConfig() *Config {

config/maintenance/maintenance_test.go

@@ -98,6 +98,15 @@ func TestConfig_ValidateAndSetDefaults(t *testing.T) {
 			},
 			expectedError: nil,
 		},
+		{
+			name: "every-day-explicitly-at-2300",
+			cfg: &Config{
+				Start:    "23:00",
+				Duration: time.Hour,
+				Every:    []string{"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"},
+			},
+			expectedError: nil,
+		},
 		{
 			name: "every-monday-at-0000",
 			cfg: &Config{
@@ -168,6 +177,24 @@ func TestConfig_IsUnderMaintenance(t *testing.T) {
 			},
 			expected: true,
 		},
+		{
+			name: "under-maintenance-starting-now-for-8h-explicit-days",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", now.Hour()),
+				Duration: 8 * time.Hour,
+				Every:    []string{"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"},
+			},
+			expected: true,
+		},
+		{
+			name: "under-maintenance-starting-now-for-23h-explicit-days",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", now.Hour()),
+				Duration: 23 * time.Hour,
+				Every:    []string{"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"},
+			},
+			expected: true,
+		},
 		{
 			name: "under-maintenance-starting-4h-ago-for-8h",
 			cfg: &Config{
@@ -176,6 +203,14 @@ func TestConfig_IsUnderMaintenance(t *testing.T) {
 			},
 			expected: true,
 		},
+		{
+			name: "under-maintenance-starting-22h-ago-for-23h",
+			cfg: &Config{
+				Start:    fmt.Sprintf("%02d:00", normalizeHour(now.Hour()-22)),
+				Duration: 23 * time.Hour,
+			},
+			expected: true,
+		},
 		{
 			name: "under-maintenance-starting-4h-ago-for-3h",
 			cfg: &Config{

config/remote/remote.go

@@ -0,0 +1,39 @@
+package remote
+
+import (
+	"log"
+
+	"github.com/TwiN/gatus/v4/client"
+)
+
+// NOTICE: This is an experimental alpha feature and may be updated/removed in future versions.
+// For more information, see https://github.com/TwiN/gatus/issues/64
+
+type Config struct {
+	// Instances is a list of remote instances to retrieve endpoint statuses from.
+	Instances []Instance `yaml:"instances,omitempty"`
+
+	// ClientConfig is the configuration of the client used to communicate with the provider's target
+	ClientConfig *client.Config `yaml:"client,omitempty"`
+}
+
+type Instance struct {
+	EndpointPrefix string `yaml:"endpoint-prefix"`
+	URL            string `yaml:"url"`
+}
+
+func (c *Config) ValidateAndSetDefaults() error {
+	if c.ClientConfig == nil {
+		c.ClientConfig = client.GetDefaultConfig()
+	} else {
+		if err := c.ClientConfig.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
+	}
+	if len(c.Instances) > 0 {
+		log.Println("WARNING: Your configuration is using 'remote', which is in alpha and may be updated/removed in future versions.")
+		log.Println("WARNING: See https://github.com/TwiN/gatus/issues/64 for more information")
+		log.Println("WARNING: This feature is a candidate for removal in future versions. Please comment on the issue above if you need this feature.")
+	}
+	return nil
+}

config/ui/ui.go

@@ -2,31 +2,53 @@ package ui
 
 import (
 	"bytes"
+	"errors"
 	"html/template"
+
+	"github.com/TwiN/gatus/v4/web"
 )
 
 const (
 	defaultTitle  = "Health Dashboard | Gatus"
+	defaultHeader = "Health Status"
 	defaultLogo   = ""
+	defaultLink   = ""
 )
 
 var (
-	// StaticFolder is the path to the location of the static folder from the root path of the project
+	ErrButtonValidationFailed = errors.New("invalid button configuration: missing required name or link")
-	// The only reason this is exposed is to allow running tests from a different path than the root path of the project
-	StaticFolder = "./web/static"
 )
 
 // Config is the configuration for the UI of Gatus
 type Config struct {
-	Title string `yaml:"title"` // Title of the page
+	Title   string   `yaml:"title,omitempty"`   // Title of the page
-	Logo  string `yaml:"logo"`  // Logo to display on the page
+	Header  string   `yaml:"header,omitempty"`  // Header is the text at the top of the page
+	Logo    string   `yaml:"logo,omitempty"`    // Logo to display on the page
+	Link    string   `yaml:"link,omitempty"`    // Link to open when clicking on the logo
+	Buttons []Button `yaml:"buttons,omitempty"` // Buttons to display below the header
+}
+
+// Button is the configuration for a button on the UI
+type Button struct {
+	Name string `yaml:"name,omitempty"` // Name is the text to display on the button
+	Link string `yaml:"link,omitempty"` // Link to open when the button is clicked.
+}
+
+// Validate validates the button configuration
+func (btn *Button) Validate() error {
+	if len(btn.Name) == 0 || len(btn.Link) == 0 {
+		return ErrButtonValidationFailed
+	}
+	return nil
 }
 
 // GetDefaultConfig returns a Config struct with the default values
 func GetDefaultConfig() *Config {
 	return &Config{
 		Title:  defaultTitle,
+		Header: defaultHeader,
 		Logo:   defaultLogo,
+		Link:   defaultLink,
 	}
 }
 
@@ -35,7 +57,19 @@ func (cfg *Config) ValidateAndSetDefaults() error {
 	if len(cfg.Title) == 0 {
 		cfg.Title = defaultTitle
 	}
-	t, err := template.ParseFiles(StaticFolder + "/index.html")
+	if len(cfg.Header) == 0 {
+		cfg.Header = defaultHeader
+	}
+	if len(cfg.Header) == 0 {
+		cfg.Header = defaultLink
+	}
+	for _, btn := range cfg.Buttons {
+		if err := btn.Validate(); err != nil {
+			return err
+		}
+	}
+	// Validate that the template works
+	t, err := template.ParseFS(static.FileSystem, static.IndexPath)
 	if err != nil {
 		return err
 	}

config/ui/ui_test.go

@@ -1,18 +1,65 @@
 package ui
 
 import (
+	"strconv"
 	"testing"
 )
 
 func TestConfig_ValidateAndSetDefaults(t *testing.T) {
-	StaticFolder = "../../web/static"
+	cfg := &Config{
-	defer func() {
+		Title:  "",
-		StaticFolder = "./web/static"
+		Header: "",
-	}()
+		Logo:   "",
-	cfg := &Config{Title: ""}
+		Link:   "",
+	}
 	if err := cfg.ValidateAndSetDefaults(); err != nil {
 		t.Error("expected no error, got", err.Error())
 	}
+	if cfg.Title != defaultTitle {
+		t.Errorf("expected title to be %s, got %s", defaultTitle, cfg.Title)
+	}
+	if cfg.Header != defaultHeader {
+		t.Errorf("expected header to be %s, got %s", defaultHeader, cfg.Header)
+	}
+}
+
+func TestButton_Validate(t *testing.T) {
+	scenarios := []struct {
+		Name, Link    string
+		ExpectedError error
+	}{
+		{
+			Name:          "",
+			Link:          "",
+			ExpectedError: ErrButtonValidationFailed,
+		},
+		{
+			Name:          "",
+			Link:          "link",
+			ExpectedError: ErrButtonValidationFailed,
+		},
+		{
+			Name:          "name",
+			Link:          "",
+			ExpectedError: ErrButtonValidationFailed,
+		},
+		{
+			Name:          "name",
+			Link:          "link",
+			ExpectedError: nil,
+		},
+	}
+	for i, scenario := range scenarios {
+		t.Run(strconv.Itoa(i)+"_"+scenario.Name+"_"+scenario.Link, func(t *testing.T) {
+			button := &Button{
+				Name: scenario.Name,
+				Link: scenario.Link,
+			}
+			if err := button.Validate(); err != scenario.ExpectedError {
+				t.Errorf("expected error %v, got %v", scenario.ExpectedError, err)
+			}
+		})
+	}
 }
 
 func TestGetDefaultConfig(t *testing.T) {

controller/controller.go

@@ -8,10 +8,8 @@ import (
 	"os"
 	"time"
 
-	"github.com/TwiN/gatus/v3/config/ui"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/config/web"
+	"github.com/TwiN/gatus/v4/controller/handler"
-	"github.com/TwiN/gatus/v3/controller/handler"
-	"github.com/TwiN/gatus/v3/security"
 )
 
 var (
@@ -21,19 +19,19 @@ var (
 )
 
 // Handle creates the router and starts the server
-func Handle(securityConfig *security.Config, webConfig *web.Config, uiConfig *ui.Config, enableMetrics bool) {
+func Handle(cfg *config.Config) {
-	var router http.Handler = handler.CreateRouter(ui.StaticFolder, securityConfig, uiConfig, enableMetrics)
+	var router http.Handler = handler.CreateRouter(cfg)
 	if os.Getenv("ENVIRONMENT") == "dev" {
 		router = handler.DevelopmentCORS(router)
 	}
 	server = &http.Server{
-		Addr:         fmt.Sprintf("%s:%d", webConfig.Address, webConfig.Port),
+		Addr:         fmt.Sprintf("%s:%d", cfg.Web.Address, cfg.Web.Port),
 		Handler:      router,
 		ReadTimeout:  15 * time.Second,
 		WriteTimeout: 15 * time.Second,
 		IdleTimeout:  15 * time.Second,
 	}
-	log.Println("[controller][Handle] Listening on " + webConfig.SocketAddress())
+	log.Println("[controller][Handle] Listening on " + cfg.Web.SocketAddress())
 	if os.Getenv("ROUTER_TEST") == "true" {
 		return
 	}

controller/controller_test.go

@@ -7,9 +7,9 @@ import (
 	"os"
 	"testing"
 
-	"github.com/TwiN/gatus/v3/config"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/config/web"
+	"github.com/TwiN/gatus/v4/config/web"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
 )
 
 func TestHandle(t *testing.T) {
@@ -32,7 +32,7 @@ func TestHandle(t *testing.T) {
 	_ = os.Setenv("ROUTER_TEST", "true")
 	_ = os.Setenv("ENVIRONMENT", "dev")
 	defer os.Clearenv()
-	Handle(cfg.Security, cfg.Web, cfg.UI, cfg.Metrics)
+	Handle(cfg)
 	defer Shutdown()
 	request, _ := http.NewRequest("GET", "/health", http.NoBody)
 	responseRecorder := httptest.NewRecorder()

controller/handler/badge.go

@@ -7,8 +7,10 @@ import (
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/storage/store/common"
+	"github.com/TwiN/gatus/v4/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store/common"
+	"github.com/TwiN/gatus/v4/storage/store/common/paging"
 	"github.com/gorilla/mux"
 )
 
@@ -21,6 +23,16 @@ const (
 	badgeColorHexVeryBad  = "#c7130a"
 )
 
+const (
+	HealthStatusUp      = "up"
+	HealthStatusDown    = "down"
+	HealthStatusUnknown = "?"
+)
+
+var (
+	badgeColors = []string{badgeColorHexAwesome, badgeColorHexGreat, badgeColorHexGood, badgeColorHexPassable, badgeColorHexBad}
+)
+
 // UptimeBadge handles the automatic generation of badge based on the group name and endpoint name passed.
 //
 // Valid values for {duration}: 7d, 24h, 1h
@@ -51,18 +63,18 @@ func UptimeBadge(writer http.ResponseWriter, request *http.Request) {
 		}
 		return
 	}
-	formattedDate := time.Now().Format(http.TimeFormat)
-	writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-	writer.Header().Set("Date", formattedDate)
-	writer.Header().Set("Expires", formattedDate)
 	writer.Header().Set("Content-Type", "image/svg+xml")
+	writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	writer.Header().Set("Expires", "0")
+	writer.WriteHeader(http.StatusOK)
 	_, _ = writer.Write(generateUptimeBadgeSVG(duration, uptime))
 }
 
 // ResponseTimeBadge handles the automatic generation of badge based on the group name and endpoint name passed.
 //
 // Valid values for {duration}: 7d, 24h, 1h
-func ResponseTimeBadge(writer http.ResponseWriter, request *http.Request) {
+func ResponseTimeBadge(config *config.Config) http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
 		variables := mux.Vars(request)
 		duration := variables["duration"]
 		var from time.Time
@@ -89,12 +101,43 @@ func ResponseTimeBadge(writer http.ResponseWriter, request *http.Request) {
 			}
 			return
 		}
-	formattedDate := time.Now().Format(http.TimeFormat)
-	writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-	writer.Header().Set("Date", formattedDate)
-	writer.Header().Set("Expires", formattedDate)
 		writer.Header().Set("Content-Type", "image/svg+xml")
-	_, _ = writer.Write(generateResponseTimeBadgeSVG(duration, averageResponseTime))
+		writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+		writer.Header().Set("Expires", "0")
+		writer.WriteHeader(http.StatusOK)
+		_, _ = writer.Write(generateResponseTimeBadgeSVG(duration, averageResponseTime, key, config))
+	}
+}
+
+// HealthBadge handles the automatic generation of badge based on the group name and endpoint name passed.
+func HealthBadge(writer http.ResponseWriter, request *http.Request) {
+	variables := mux.Vars(request)
+	key := variables["key"]
+	pagingConfig := paging.NewEndpointStatusParams()
+	status, err := store.Get().GetEndpointStatusByKey(key, pagingConfig.WithResults(1, 1))
+	if err != nil {
+		if err == common.ErrEndpointNotFound {
+			http.Error(writer, err.Error(), http.StatusNotFound)
+		} else if err == common.ErrInvalidTimeRange {
+			http.Error(writer, err.Error(), http.StatusBadRequest)
+		} else {
+			http.Error(writer, err.Error(), http.StatusInternalServerError)
+		}
+		return
+	}
+	healthStatus := HealthStatusUnknown
+	if len(status.Results) > 0 {
+		if status.Results[0].Success {
+			healthStatus = HealthStatusUp
+		} else {
+			healthStatus = HealthStatusDown
+		}
+	}
+	writer.Header().Set("Content-Type", "image/svg+xml")
+	writer.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	writer.Header().Set("Expires", "0")
+	writer.WriteHeader(http.StatusOK)
+	_, _ = writer.Write(generateHealthBadgeSVG(healthStatus))
 }
 
 func generateUptimeBadgeSVG(duration string, uptime float64) []byte {
@@ -163,7 +206,7 @@ func getBadgeColorFromUptime(uptime float64) string {
 	return badgeColorHexVeryBad
 }
 
-func generateResponseTimeBadgeSVG(duration string, averageResponseTime int) []byte {
+func generateResponseTimeBadgeSVG(duration string, averageResponseTime int, key string, cfg *config.Config) []byte {
 	var labelWidth, valueWidth int
 	switch duration {
 	case "7d":
@@ -174,7 +217,7 @@ func generateResponseTimeBadgeSVG(duration string, averageResponseTime int) []by
 		labelWidth = 105
 	default:
 	}
-	color := getBadgeColorFromResponseTime(averageResponseTime)
+	color := getBadgeColorFromResponseTime(averageResponseTime, key, cfg)
 	sanitizedValue := strconv.Itoa(averageResponseTime) + "ms"
 	valueWidth = len(sanitizedValue) * 11
 	width := labelWidth + valueWidth
@@ -211,17 +254,71 @@ func generateResponseTimeBadgeSVG(duration string, averageResponseTime int) []by
 	return svg
 }
 
-func getBadgeColorFromResponseTime(responseTime int) string {
+func getBadgeColorFromResponseTime(responseTime int, key string, cfg *config.Config) string {
-	if responseTime <= 50 {
+	endpoint := cfg.GetEndpointByKey(key)
-		return badgeColorHexAwesome
+	// the threshold config requires 5 values, so we can be sure it's set here
-	} else if responseTime <= 200 {
+	for i := 0; i < 5; i++ {
-		return badgeColorHexGreat
+		if responseTime <= endpoint.UIConfig.Badge.ResponseTime.Thresholds[i] {
-	} else if responseTime <= 300 {
+			return badgeColors[i]
-		return badgeColorHexGood
+		}
-	} else if responseTime <= 500 {
-		return badgeColorHexPassable
-	} else if responseTime <= 750 {
-		return badgeColorHexBad
 	}
 	return badgeColorHexVeryBad
 }
+
+func generateHealthBadgeSVG(healthStatus string) []byte {
+	var labelWidth, valueWidth int
+	switch healthStatus {
+	case HealthStatusUp:
+		valueWidth = 28
+	case HealthStatusDown:
+		valueWidth = 44
+	case HealthStatusUnknown:
+		valueWidth = 10
+	default:
+	}
+	color := getBadgeColorFromHealth(healthStatus)
+	labelWidth = 48
+
+	width := labelWidth + valueWidth
+	labelX := labelWidth / 2
+	valueX := labelWidth + (valueWidth / 2)
+	svg := []byte(fmt.Sprintf(`<svg xmlns="http://www.w3.org/2000/svg" width="%d" height="20">
+  <linearGradient id="b" x2="0" y2="100%%">
+    <stop offset="0" stop-color="#bbb" stop-opacity=".1"/>
+    <stop offset="1" stop-opacity=".1"/>
+  </linearGradient>
+  <mask id="a">
+    <rect width="%d" height="20" rx="3" fill="#fff"/>
+  </mask>
+  <g mask="url(#a)">
+    <path fill="#555" d="M0 0h%dv20H0z"/>
+    <path fill="%s" d="M%d 0h%dv20H%dz"/>
+    <path fill="url(#b)" d="M0 0h%dv20H0z"/>
+  </g>
+  <g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="11">
+    <text x="%d" y="15" fill="#010101" fill-opacity=".3">
+      health
+    </text>
+    <text x="%d" y="14">
+      health
+    </text>
+    <text x="%d" y="15" fill="#010101" fill-opacity=".3">
+      %s
+    </text>
+    <text x="%d" y="14">
+      %s
+    </text>
+  </g>
+</svg>`, width, width, labelWidth, color, labelWidth, valueWidth, labelWidth, width, labelX, labelX, valueX, healthStatus, valueX, healthStatus))
+
+	return svg
+}
+
+func getBadgeColorFromHealth(healthStatus string) string {
+	if healthStatus == HealthStatusUp {
+		return badgeColorHexAwesome
+	} else if healthStatus == HealthStatusDown {
+		return badgeColorHexVeryBad
+	}
+	return badgeColorHexPassable
+}

controller/handler/badge_test.go

@@ -7,13 +7,14 @@ import (
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/config"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/core/ui"
-	"github.com/TwiN/gatus/v3/watchdog"
+	"github.com/TwiN/gatus/v4/storage/store"
+	"github.com/TwiN/gatus/v4/watchdog"
 )
 
-func TestUptimeBadge(t *testing.T) {
+func TestBadge(t *testing.T) {
 	defer store.Get().Clear()
 	defer cache.Clear()
 	cfg := &config.Config{
@@ -29,9 +30,39 @@ func TestUptimeBadge(t *testing.T) {
 			},
 		},
 	}
-	watchdog.UpdateEndpointStatuses(cfg.Endpoints[0], &core.Result{Success: true, Duration: time.Millisecond, Timestamp: time.Now()})
+
-	watchdog.UpdateEndpointStatuses(cfg.Endpoints[1], &core.Result{Success: false, Duration: time.Second, Timestamp: time.Now()})
+	testSuccessfulResult = core.Result{
-	router := CreateRouter("../../web/static", cfg.Security, nil, cfg.Metrics)
+		Hostname:              "example.org",
+		IP:                    "127.0.0.1",
+		HTTPStatus:            200,
+		Errors:                nil,
+		Connected:             true,
+		Success:               true,
+		Timestamp:             timestamp,
+		Duration:              150 * time.Millisecond,
+		CertificateExpiration: 10 * time.Hour,
+		ConditionResults: []*core.ConditionResult{
+			{
+				Condition: "[STATUS] == 200",
+				Success:   true,
+			},
+			{
+				Condition: "[RESPONSE_TIME] < 500",
+				Success:   true,
+			},
+			{
+				Condition: "[CERTIFICATE_EXPIRATION] < 72h",
+				Success:   true,
+			},
+		},
+	}
+
+	cfg.Endpoints[0].UIConfig = ui.GetDefaultConfig()
+	cfg.Endpoints[1].UIConfig = ui.GetDefaultConfig()
+
+	watchdog.UpdateEndpointStatuses(cfg.Endpoints[0], &core.Result{Success: true, Connected: true, Duration: time.Millisecond, Timestamp: time.Now()})
+	watchdog.UpdateEndpointStatuses(cfg.Endpoints[1], &core.Result{Success: false, Connected: false, Duration: time.Second, Timestamp: time.Now()})
+	router := CreateRouter(cfg)
 	type Scenario struct {
 		Name         string
 		Path         string
@@ -89,20 +120,35 @@ func TestUptimeBadge(t *testing.T) {
 			Path:         "/api/v1/endpoints/invalid_key/response-times/7d/badge.svg",
 			ExpectedCode: http.StatusNotFound,
 		},
+		{
+			Name:         "badge-health-up",
+			Path:         "/api/v1/endpoints/core_frontend/health/badge.svg",
+			ExpectedCode: http.StatusOK,
+		},
+		{
+			Name:         "badge-health-down",
+			Path:         "/api/v1/endpoints/core_backend/health/badge.svg",
+			ExpectedCode: http.StatusOK,
+		},
+		{
+			Name:         "badge-health-for-invalid-key",
+			Path:         "/api/v1/endpoints/invalid_key/health/badge.svg",
+			ExpectedCode: http.StatusNotFound,
+		},
 		{
 			Name:         "chart-response-time-24h",
 			Path:         "/api/v1/endpoints/core_backend/response-times/24h/chart.svg",
 			ExpectedCode: http.StatusOK,
 		},
-		{ // XXX: Remove this in v4.0.0
+		{
-			Name:         "backward-compatible-services-badge-uptime-1h",
+			Name:         "chart-response-time-7d",
-			Path:         "/api/v1/services/core_frontend/uptimes/1h/badge.svg",
+			Path:         "/api/v1/endpoints/core_frontend/response-times/7d/chart.svg",
 			ExpectedCode: http.StatusOK,
 		},
-		{ // XXX: Remove this in v4.0.0
+		{
-			Name:         "backward-compatible-services-chart-response-time-24h",
+			Name:         "chart-response-time-with-invalid-duration",
-			Path:         "/api/v1/services/core_backend/response-times/24h/chart.svg",
+			Path:         "/api/v1/endpoints/core_backend/response-times/3d/chart.svg",
-			ExpectedCode: http.StatusOK,
+			ExpectedCode: http.StatusBadRequest,
 		},
 	}
 	for _, scenario := range scenarios {
@@ -176,55 +222,155 @@ func TestGetBadgeColorFromUptime(t *testing.T) {
 }
 
 func TestGetBadgeColorFromResponseTime(t *testing.T) {
+	defer store.Get().Clear()
+	defer cache.Clear()
+
+	var (
+		firstCondition  = core.Condition("[STATUS] == 200")
+		secondCondition = core.Condition("[RESPONSE_TIME] < 500")
+		thirdCondition  = core.Condition("[CERTIFICATE_EXPIRATION] < 72h")
+	)
+
+	firstTestEndpoint := core.Endpoint{
+		Name:                    "a",
+		URL:                     "https://example.org/what/ever",
+		Method:                  "GET",
+		Body:                    "body",
+		Interval:                30 * time.Second,
+		Conditions:              []core.Condition{firstCondition, secondCondition, thirdCondition},
+		Alerts:                  nil,
+		NumberOfFailuresInARow:  0,
+		NumberOfSuccessesInARow: 0,
+		UIConfig:                ui.GetDefaultConfig(),
+	}
+	secondTestEndpoint := core.Endpoint{
+		Name:                    "b",
+		URL:                     "https://example.org/what/ever",
+		Method:                  "GET",
+		Body:                    "body",
+		Interval:                30 * time.Second,
+		Conditions:              []core.Condition{firstCondition, secondCondition, thirdCondition},
+		Alerts:                  nil,
+		NumberOfFailuresInARow:  0,
+		NumberOfSuccessesInARow: 0,
+		UIConfig: &ui.Config{
+			Badge: &ui.Badge{
+				ResponseTime: &ui.ResponseTime{
+					Thresholds: []int{100, 500, 1000, 2000, 3000},
+				},
+			},
+		},
+	}
+	cfg := &config.Config{
+		Metrics:   true,
+		Endpoints: []*core.Endpoint{&firstTestEndpoint, &secondTestEndpoint},
+	}
+
+	store.Get().Insert(&firstTestEndpoint, &testSuccessfulResult)
+	store.Get().Insert(&secondTestEndpoint, &testSuccessfulResult)
+
 	scenarios := []struct {
+		Key           string
 		ResponseTime  int
 		ExpectedColor string
 	}{
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  10,
 			ExpectedColor: badgeColorHexAwesome,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  50,
 			ExpectedColor: badgeColorHexAwesome,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  75,
 			ExpectedColor: badgeColorHexGreat,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  150,
 			ExpectedColor: badgeColorHexGreat,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  201,
 			ExpectedColor: badgeColorHexGood,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  300,
 			ExpectedColor: badgeColorHexGood,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  301,
 			ExpectedColor: badgeColorHexPassable,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  450,
 			ExpectedColor: badgeColorHexPassable,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  700,
 			ExpectedColor: badgeColorHexBad,
 		},
 		{
+			Key:           firstTestEndpoint.Key(),
 			ResponseTime:  1500,
 			ExpectedColor: badgeColorHexVeryBad,
 		},
+		{
+			Key:           secondTestEndpoint.Key(),
+			ResponseTime:  50,
+			ExpectedColor: badgeColorHexAwesome,
+		},
+		{
+			Key:           secondTestEndpoint.Key(),
+			ResponseTime:  1500,
+			ExpectedColor: badgeColorHexPassable,
+		},
+		{
+			Key:           secondTestEndpoint.Key(),
+			ResponseTime:  2222,
+			ExpectedColor: badgeColorHexBad,
+		},
 	}
 	for _, scenario := range scenarios {
-		t.Run("response-time-"+strconv.Itoa(scenario.ResponseTime), func(t *testing.T) {
+		t.Run(scenario.Key+"-response-time-"+strconv.Itoa(scenario.ResponseTime), func(t *testing.T) {
-			if getBadgeColorFromResponseTime(scenario.ResponseTime) != scenario.ExpectedColor {
+			if getBadgeColorFromResponseTime(scenario.ResponseTime, scenario.Key, cfg) != scenario.ExpectedColor {
-				t.Errorf("expected %s from %d, got %v", scenario.ExpectedColor, scenario.ResponseTime, getBadgeColorFromResponseTime(scenario.ResponseTime))
+				t.Errorf("expected %s from %d, got %v", scenario.ExpectedColor, scenario.ResponseTime, getBadgeColorFromResponseTime(scenario.ResponseTime, scenario.Key, cfg))
+			}
+		})
+	}
+}
+
+func TestGetBadgeColorFromHealth(t *testing.T) {
+	scenarios := []struct {
+		HealthStatus  string
+		ExpectedColor string
+	}{
+		{
+			HealthStatus:  HealthStatusUp,
+			ExpectedColor: badgeColorHexAwesome,
+		},
+		{
+			HealthStatus:  HealthStatusDown,
+			ExpectedColor: badgeColorHexVeryBad,
+		},
+		{
+			HealthStatus:  HealthStatusUnknown,
+			ExpectedColor: badgeColorHexPassable,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run("health-"+scenario.HealthStatus, func(t *testing.T) {
+			if getBadgeColorFromHealth(scenario.HealthStatus) != scenario.ExpectedColor {
+				t.Errorf("expected %s from %s, got %v", scenario.ExpectedColor, scenario.HealthStatus, getBadgeColorFromHealth(scenario.HealthStatus))
 			}
 		})
 	}

controller/handler/chart.go

@@ -7,8 +7,8 @@ import (
 	"sort"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store"
-	"github.com/TwiN/gatus/v3/storage/store/common"
+	"github.com/TwiN/gatus/v4/storage/store/common"
 	"github.com/gorilla/mux"
 	"github.com/wcharczuk/go-chart/v2"
 	"github.com/wcharczuk/go-chart/v2/drawing"
@@ -112,6 +112,9 @@ func ResponseTimeChart(writer http.ResponseWriter, r *http.Request) {
 		Series: []chart.Series{series},
 	}
 	writer.Header().Set("Content-Type", "image/svg+xml")
+	writer.Header().Set("Cache-Control", "no-cache, no-store")
+	writer.Header().Set("Expires", "0")
+	writer.WriteHeader(http.StatusOK)
 	if err := graph.Render(chart.SVG, writer); err != nil {
 		log.Println("[handler][ResponseTimeChart] Failed to render response time chart:", err.Error())
 		return

controller/handler/chart_test.go

@@ -6,10 +6,10 @@ import (
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/config"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store"
-	"github.com/TwiN/gatus/v3/watchdog"
+	"github.com/TwiN/gatus/v4/watchdog"
 )
 
 func TestResponseTimeChart(t *testing.T) {
@@ -30,7 +30,7 @@ func TestResponseTimeChart(t *testing.T) {
 	}
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[0], &core.Result{Success: true, Duration: time.Millisecond, Timestamp: time.Now()})
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[1], &core.Result{Success: false, Duration: time.Second, Timestamp: time.Now()})
-	router := CreateRouter("../../web/static", cfg.Security, nil, cfg.Metrics)
+	router := CreateRouter(cfg)
 	type Scenario struct {
 		Name         string
 		Path         string
@@ -58,11 +58,6 @@ func TestResponseTimeChart(t *testing.T) {
 			Path:         "/api/v1/endpoints/invalid_key/response-times/7d/chart.svg",
 			ExpectedCode: http.StatusNotFound,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-services-chart-response-time-24h",
-			Path:         "/api/v1/services/core_backend/response-times/24h/chart.svg",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {

controller/handler/config.go

@@ -0,0 +1,26 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/TwiN/gatus/v4/security"
+)
+
+// ConfigHandler is a handler that returns information for the front end of the application.
+type ConfigHandler struct {
+	securityConfig *security.Config
+}
+
+func (handler ConfigHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	hasOIDC := false
+	isAuthenticated := true // Default to true if no security config is set
+	if handler.securityConfig != nil {
+		hasOIDC = handler.securityConfig.OIDC != nil
+		isAuthenticated = handler.securityConfig.IsAuthenticated(r)
+	}
+	// Return the config
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte(fmt.Sprintf(`{"oidc":%v,"authenticated":%v}`, hasOIDC, isAuthenticated)))
+}

controller/handler/config_test.go

@@ -0,0 +1,34 @@
+package handler
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/TwiN/gatus/v4/security"
+	"github.com/gorilla/mux"
+)
+
+func TestConfigHandler_ServeHTTP(t *testing.T) {
+	securityConfig := &security.Config{
+		OIDC: &security.OIDCConfig{
+			IssuerURL:       "https://sso.gatus.io/",
+			RedirectURL:     "http://localhost:80/authorization-code/callback",
+			Scopes:          []string{"openid"},
+			AllowedSubjects: []string{"user1@example.com"},
+		},
+	}
+	handler := ConfigHandler{securityConfig: securityConfig}
+	// Create a fake router. We're doing this because I need the gate to be initialized.
+	securityConfig.ApplySecurityMiddleware(mux.NewRouter())
+	// Test the config handler
+	request, _ := http.NewRequest("GET", "/api/v1/config", http.NoBody)
+	responseRecorder := httptest.NewRecorder()
+	handler.ServeHTTP(responseRecorder, request)
+	if responseRecorder.Code != http.StatusOK {
+		t.Error("expected code to be 200, but was", responseRecorder.Code)
+	}
+	if responseRecorder.Body.String() != `{"oidc":true,"authenticated":false}` {
+		t.Error("expected body to be `{\"oidc\":true,\"authenticated\":false}`, but was", responseRecorder.Body.String())
+	}
+}

controller/handler/cors.go

@@ -4,7 +4,11 @@ import "net/http"
 
 func DevelopmentCORS(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Credentials", "true")
 		w.Header().Set("Access-Control-Allow-Origin", "http://localhost:8081")
+		if r.Method == "OPTIONS" {
+			return
+		}
 		next.ServeHTTP(w, r)
 	})
 }

controller/handler/endpoint_status.go

@@ -5,15 +5,20 @@ import (
 	"compress/gzip"
 	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"net/http"
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/storage/store/common"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/storage/store/common/paging"
+	"github.com/TwiN/gatus/v4/config/remote"
-	"github.com/TwiN/gocache"
+	"github.com/TwiN/gatus/v4/core"
+	"github.com/TwiN/gatus/v4/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store/common"
+	"github.com/TwiN/gatus/v4/storage/store/common/paging"
+	"github.com/TwiN/gocache/v2"
 	"github.com/gorilla/mux"
 )
 
@@ -28,7 +33,8 @@ var (
 // EndpointStatuses handles requests to retrieve all EndpointStatus
 // Due to the size of the response, this function leverages a cache.
 // Must not be wrapped by GzipHandler
-func EndpointStatuses(writer http.ResponseWriter, r *http.Request) {
+func EndpointStatuses(cfg *config.Config) http.HandlerFunc {
+	return func(writer http.ResponseWriter, r *http.Request) {
 		page, pageSize := extractPageAndPageSizeFromRequest(r)
 		gzipped := strings.Contains(r.Header.Get("Accept-Encoding"), "gzip")
 		var exists bool
@@ -50,6 +56,13 @@ func EndpointStatuses(writer http.ResponseWriter, r *http.Request) {
 				http.Error(writer, err.Error(), http.StatusInternalServerError)
 				return
 			}
+			// ALPHA: Retrieve endpoint statuses from remote instances
+			if endpointStatusesFromRemote, err := getEndpointStatusesFromRemoteInstances(cfg.Remote); err != nil {
+				log.Printf("[handler][EndpointStatuses] Silently failed to retrieve endpoint statuses from remote: %s", err.Error())
+			} else if endpointStatusesFromRemote != nil {
+				endpointStatuses = append(endpointStatuses, endpointStatusesFromRemote...)
+			}
+			// Marshal endpoint statuses to JSON
 			data, err = json.Marshal(endpointStatuses)
 			if err != nil {
 				log.Printf("[handler][EndpointStatuses] Unable to marshal object to JSON: %s", err.Error())
@@ -71,6 +84,39 @@ func EndpointStatuses(writer http.ResponseWriter, r *http.Request) {
 		writer.WriteHeader(http.StatusOK)
 		_, _ = writer.Write(data)
 	}
+}
+
+func getEndpointStatusesFromRemoteInstances(remoteConfig *remote.Config) ([]*core.EndpointStatus, error) {
+	if remoteConfig == nil || len(remoteConfig.Instances) == 0 {
+		return nil, nil
+	}
+	var endpointStatusesFromAllRemotes []*core.EndpointStatus
+	httpClient := client.GetHTTPClient(remoteConfig.ClientConfig)
+	for _, instance := range remoteConfig.Instances {
+		response, err := httpClient.Get(instance.URL)
+		if err != nil {
+			return nil, err
+		}
+		body, err := io.ReadAll(response.Body)
+		if err != nil {
+			_ = response.Body.Close()
+			log.Printf("[handler][getEndpointStatusesFromRemoteInstances] Silently failed to retrieve endpoint statuses from %s: %s", instance.URL, err.Error())
+			continue
+		}
+		var endpointStatuses []*core.EndpointStatus
+		if err = json.Unmarshal(body, &endpointStatuses); err != nil {
+			_ = response.Body.Close()
+			log.Printf("[handler][getEndpointStatusesFromRemoteInstances] Silently failed to retrieve endpoint statuses from %s: %s", instance.URL, err.Error())
+			continue
+		}
+		_ = response.Body.Close()
+		for _, endpointStatus := range endpointStatuses {
+			endpointStatus.Name = instance.EndpointPrefix + endpointStatus.Name
+		}
+		endpointStatusesFromAllRemotes = append(endpointStatusesFromAllRemotes, endpointStatuses...)
+	}
+	return endpointStatusesFromAllRemotes, nil
+}
 
 // EndpointStatus retrieves a single core.EndpointStatus by group and endpoint name
 func EndpointStatus(writer http.ResponseWriter, r *http.Request) {

controller/handler/endpoint_status_test.go

@@ -6,17 +6,13 @@ import (
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/config"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store"
-	"github.com/TwiN/gatus/v3/watchdog"
+	"github.com/TwiN/gatus/v4/watchdog"
 )
 
 var (
-	firstCondition  = core.Condition("[STATUS] == 200")
-	secondCondition = core.Condition("[RESPONSE_TIME] < 500")
-	thirdCondition  = core.Condition("[CERTIFICATE_EXPIRATION] < 72h")
-
 	timestamp = time.Now()
 
 	testEndpoint = core.Endpoint{
@@ -26,7 +22,7 @@ var (
 		Method:                  "GET",
 		Body:                    "body",
 		Interval:                30 * time.Second,
-		Conditions:              []*core.Condition{&firstCondition, &secondCondition, &thirdCondition},
+		Conditions:              []core.Condition{core.Condition("[STATUS] == 200"), core.Condition("[RESPONSE_TIME] < 500"), core.Condition("[CERTIFICATE_EXPIRATION] < 72h")},
 		Alerts:                  nil,
 		NumberOfFailuresInARow:  0,
 		NumberOfSuccessesInARow: 0,
@@ -101,7 +97,7 @@ func TestEndpointStatus(t *testing.T) {
 	}
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[0], &core.Result{Success: true, Duration: time.Millisecond, Timestamp: time.Now()})
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[1], &core.Result{Success: false, Duration: time.Second, Timestamp: time.Now()})
-	router := CreateRouter("../../web/static", cfg.Security, nil, cfg.Metrics)
+	router := CreateRouter(cfg)
 
 	type Scenario struct {
 		Name         string
@@ -131,11 +127,6 @@ func TestEndpointStatus(t *testing.T) {
 			Path:         "/api/v1/endpoints/invalid_key/statuses",
 			ExpectedCode: http.StatusNotFound,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-service-status",
-			Path:         "/api/v1/services/core_frontend/statuses",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {
@@ -162,7 +153,7 @@ func TestEndpointStatuses(t *testing.T) {
 	// Can't be bothered dealing with timezone issues on the worker that runs the automated tests
 	firstResult.Timestamp = time.Time{}
 	secondResult.Timestamp = time.Time{}
-	router := CreateRouter("../../web/static", nil, nil, false)
+	router := CreateRouter(&config.Config{Metrics: true})
 
 	type Scenario struct {
 		Name         string
@@ -201,12 +192,6 @@ func TestEndpointStatuses(t *testing.T) {
 			ExpectedCode: http.StatusOK,
 			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "backward-compatible-service-status",
-			Path:         "/api/v1/services/statuses",
-			ExpectedCode: http.StatusOK,
-			ExpectedBody: `[{"name":"name","group":"group","key":"group_name","results":[{"status":200,"hostname":"example.org","duration":150000000,"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":true},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":true}],"success":true,"timestamp":"0001-01-01T00:00:00Z"},{"status":200,"hostname":"example.org","duration":750000000,"errors":["error-1","error-2"],"conditionResults":[{"condition":"[STATUS] == 200","success":true},{"condition":"[RESPONSE_TIME] \u003c 500","success":false},{"condition":"[CERTIFICATE_EXPIRATION] \u003c 72h","success":false}],"success":false,"timestamp":"0001-01-01T00:00:00Z"}]}]`,
-		},
 	}
 
 	for _, scenario := range scenarios {

controller/handler/favicon.go

@@ -1,12 +0,0 @@
-package handler
-
-import (
-	"net/http"
-)
-
-// FavIcon handles requests for /favicon.ico
-func FavIcon(staticFolder string) http.HandlerFunc {
-	return func(writer http.ResponseWriter, request *http.Request) {
-		http.ServeFile(writer, request, staticFolder+"/favicon.ico")
-	}
-}

controller/handler/favicon_test.go

@@ -1,33 +0,0 @@
-package handler
-
-import (
-	"net/http"
-	"net/http/httptest"
-	"testing"
-)
-
-func TestFavIcon(t *testing.T) {
-	router := CreateRouter("../../web/static", nil, nil, false)
-	type Scenario struct {
-		Name         string
-		Path         string
-		ExpectedCode int
-	}
-	scenarios := []Scenario{
-		{
-			Name:         "favicon",
-			Path:         "/favicon.ico",
-			ExpectedCode: http.StatusOK,
-		},
-	}
-	for _, scenario := range scenarios {
-		t.Run(scenario.Name, func(t *testing.T) {
-			request, _ := http.NewRequest("GET", scenario.Path, http.NoBody)
-			responseRecorder := httptest.NewRecorder()
-			router.ServeHTTP(responseRecorder, request)
-			if responseRecorder.Code != scenario.ExpectedCode {
-				t.Errorf("%s %s should have returned %d, but returned %d instead", request.Method, request.URL, scenario.ExpectedCode, responseRecorder.Code)
-			}
-		})
-	}
-}

controller/handler/gzip.go

@@ -3,7 +3,6 @@ package handler
 import (
 	"compress/gzip"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"strings"
 	"sync"
@@ -11,7 +10,7 @@ import (
 
 var gzPool = sync.Pool{
 	New: func() interface{} {
-		return gzip.NewWriter(ioutil.Discard)
+		return gzip.NewWriter(io.Discard)
 	},
 }
 

controller/handler/handler.go

@@ -1,47 +1,50 @@
 package handler
 
 import (
+	"io/fs"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/config/ui"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/security"
+	"github.com/TwiN/gatus/v4/web"
 	"github.com/TwiN/health"
 	"github.com/gorilla/mux"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
-func CreateRouter(staticFolder string, securityConfig *security.Config, uiConfig *ui.Config, enabledMetrics bool) *mux.Router {
+func CreateRouter(cfg *config.Config) *mux.Router {
 	router := mux.NewRouter()
-	if enabledMetrics {
+	if cfg.Metrics {
 		router.Handle("/metrics", promhttp.Handler()).Methods("GET")
 	}
-	router.Handle("/health", health.Handler().WithJSON(true)).Methods("GET")
+	api := router.PathPrefix("/api").Subrouter()
-	router.HandleFunc("/favicon.ico", FavIcon(staticFolder)).Methods("GET")
+	protected := api.PathPrefix("/").Subrouter()
+	unprotected := api.PathPrefix("/").Subrouter()
+	if cfg.Security != nil {
+		if err := cfg.Security.RegisterHandlers(router); err != nil {
+			panic(err)
+		}
+		if err := cfg.Security.ApplySecurityMiddleware(protected); err != nil {
+			panic(err)
+		}
+	}
 	// Endpoints
-	router.HandleFunc("/api/v1/endpoints/statuses", secureIfNecessary(securityConfig, EndpointStatuses)).Methods("GET") // No GzipHandler for this one, because we cache the content as Gzipped already
+	unprotected.Handle("/v1/config", ConfigHandler{securityConfig: cfg.Security}).Methods("GET")
-	router.HandleFunc("/api/v1/endpoints/{key}/statuses", secureIfNecessary(securityConfig, GzipHandlerFunc(EndpointStatus))).Methods("GET")
+	protected.HandleFunc("/v1/endpoints/statuses", EndpointStatuses(cfg)).Methods("GET") // No GzipHandler for this one, because we cache the content as Gzipped already
-	router.HandleFunc("/api/v1/endpoints/{key}/uptimes/{duration}/badge.svg", UptimeBadge).Methods("GET")
+	protected.HandleFunc("/v1/endpoints/{key}/statuses", GzipHandlerFunc(EndpointStatus)).Methods("GET")
-	router.HandleFunc("/api/v1/endpoints/{key}/response-times/{duration}/badge.svg", ResponseTimeBadge).Methods("GET")
+	unprotected.HandleFunc("/v1/endpoints/{key}/health/badge.svg", HealthBadge).Methods("GET")
-	router.HandleFunc("/api/v1/endpoints/{key}/response-times/{duration}/chart.svg", ResponseTimeChart).Methods("GET")
+	unprotected.HandleFunc("/v1/endpoints/{key}/uptimes/{duration}/badge.svg", UptimeBadge).Methods("GET")
-	// XXX: Remove the lines between this and the next XXX comment in v4.0.0
+	unprotected.HandleFunc("/v1/endpoints/{key}/response-times/{duration}/badge.svg", ResponseTimeBadge(cfg)).Methods("GET")
-	router.HandleFunc("/api/v1/services/statuses", secureIfNecessary(securityConfig, EndpointStatuses)).Methods("GET") // No GzipHandler for this one, because we cache the content as Gzipped already
+	unprotected.HandleFunc("/v1/endpoints/{key}/response-times/{duration}/chart.svg", ResponseTimeChart).Methods("GET")
-	router.HandleFunc("/api/v1/services/{key}/statuses", secureIfNecessary(securityConfig, GzipHandlerFunc(EndpointStatus))).Methods("GET")
+	// Misc
-	router.HandleFunc("/api/v1/services/{key}/uptimes/{duration}/badge.svg", UptimeBadge).Methods("GET")
+	router.Handle("/health", health.Handler().WithJSON(true)).Methods("GET")
-	router.HandleFunc("/api/v1/services/{key}/response-times/{duration}/badge.svg", ResponseTimeBadge).Methods("GET")
-	router.HandleFunc("/api/v1/services/{key}/response-times/{duration}/chart.svg", ResponseTimeChart).Methods("GET")
-	// XXX: Remove the lines between this and the previous XXX comment in v4.0.0
 	// SPA
-	router.HandleFunc("/services/{name}", SinglePageApplication(staticFolder, uiConfig)).Methods("GET") // XXX: Remove this in v4.0.0
+	router.HandleFunc("/endpoints/{name}", SinglePageApplication(cfg.UI)).Methods("GET")
-	router.HandleFunc("/endpoints/{name}", SinglePageApplication(staticFolder, uiConfig)).Methods("GET")
+	router.HandleFunc("/", SinglePageApplication(cfg.UI)).Methods("GET")
-	router.HandleFunc("/", SinglePageApplication(staticFolder, uiConfig)).Methods("GET")
 	// Everything else falls back on static content
-	router.PathPrefix("/").Handler(GzipHandler(http.FileServer(http.Dir(staticFolder))))
+	staticFileSystem, err := fs.Sub(static.FileSystem, static.RootPath)
+	if err != nil {
+		panic(err)
+	}
+	router.PathPrefix("/").Handler(GzipHandler(http.FileServer(http.FS(staticFileSystem))))
 	return router
 }
-
-func secureIfNecessary(securityConfig *security.Config, handler http.HandlerFunc) http.HandlerFunc {
-	if securityConfig != nil && securityConfig.IsValid() {
-		return security.Handler(handler, securityConfig)
-	}
-	return handler
-}

controller/handler/handler_test.go

@@ -4,10 +4,12 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"testing"
+
+	"github.com/TwiN/gatus/v4/config"
 )
 
 func TestCreateRouter(t *testing.T) {
-	router := CreateRouter("../../web/static", nil, nil, true)
+	router := CreateRouter(&config.Config{Metrics: true})
 	type Scenario struct {
 		Name         string
 		Path         string
@@ -26,16 +28,32 @@ func TestCreateRouter(t *testing.T) {
 			ExpectedCode: http.StatusOK,
 		},
 		{
-			Name:         "scripts",
+			Name:         "favicon.ico",
+			Path:         "/favicon.ico",
+			ExpectedCode: http.StatusOK,
+		},
+		{
+			Name:         "app.js",
 			Path:         "/js/app.js",
 			ExpectedCode: http.StatusOK,
 		},
 		{
-			Name:         "scripts-gzipped",
+			Name:         "app.js-gzipped",
 			Path:         "/js/app.js",
 			ExpectedCode: http.StatusOK,
 			Gzip:         true,
 		},
+		{
+			Name:         "chunk-vendors.js",
+			Path:         "/js/chunk-vendors.js",
+			ExpectedCode: http.StatusOK,
+		},
+		{
+			Name:         "chunk-vendors.js-gzipped",
+			Path:         "/js/chunk-vendors.js",
+			ExpectedCode: http.StatusOK,
+			Gzip:         true,
+		},
 		{
 			Name:         "index-redirect",
 			Path:         "/index.html",

controller/handler/spa.go

@@ -1,26 +1,30 @@
 package handler
 
 import (
+	_ "embed"
 	"html/template"
 	"log"
 	"net/http"
 
-	"github.com/TwiN/gatus/v3/config/ui"
+	"github.com/TwiN/gatus/v4/config/ui"
+	"github.com/TwiN/gatus/v4/web"
 )
 
-func SinglePageApplication(staticFolder string, ui *ui.Config) http.HandlerFunc {
+func SinglePageApplication(ui *ui.Config) http.HandlerFunc {
 	return func(writer http.ResponseWriter, request *http.Request) {
-		t, err := template.ParseFiles(staticFolder + "/index.html")
+		t, err := template.ParseFS(static.FileSystem, static.IndexPath)
 		if err != nil {
-			log.Println("[handler][SinglePageApplication] Failed to parse template:", err.Error())
+			// This should never happen, because ui.ValidateAndSetDefaults validates that the template works.
-			http.ServeFile(writer, request, staticFolder+"/index.html")
+			log.Println("[handler][SinglePageApplication] Failed to parse template. This should never happen, because the template is validated on start. Error:", err.Error())
+			http.Error(writer, "Failed to parse template. This should never happen, because the template is validated on start.", http.StatusInternalServerError)
 			return
 		}
 		writer.Header().Set("Content-Type", "text/html")
 		err = t.Execute(writer, ui)
 		if err != nil {
-			log.Println("[handler][SinglePageApplication] Failed to parse template:", err.Error())
+			// This should never happen, because ui.ValidateAndSetDefaults validates that the template works.
-			http.ServeFile(writer, request, staticFolder+"/index.html")
+			log.Println("[handler][SinglePageApplication] Failed to execute template. This should never happen, because the template is validated on start. Error:", err.Error())
+			http.Error(writer, "Failed to execute template. This should never happen, because the template is validated on start.", http.StatusInternalServerError)
 			return
 		}
 	}

controller/handler/spa_test.go

@@ -6,10 +6,10 @@ import (
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/config"
+	"github.com/TwiN/gatus/v4/config"
-	"github.com/TwiN/gatus/v3/core"
+	"github.com/TwiN/gatus/v4/core"
-	"github.com/TwiN/gatus/v3/storage/store"
+	"github.com/TwiN/gatus/v4/storage/store"
-	"github.com/TwiN/gatus/v3/watchdog"
+	"github.com/TwiN/gatus/v4/watchdog"
 )
 
 func TestSinglePageApplication(t *testing.T) {
@@ -30,7 +30,7 @@ func TestSinglePageApplication(t *testing.T) {
 	}
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[0], &core.Result{Success: true, Duration: time.Millisecond, Timestamp: time.Now()})
 	watchdog.UpdateEndpointStatuses(cfg.Endpoints[1], &core.Result{Success: false, Duration: time.Second, Timestamp: time.Now()})
-	router := CreateRouter("../../web/static", cfg.Security, nil, cfg.Metrics)
+	router := CreateRouter(cfg)
 	type Scenario struct {
 		Name         string
 		Path         string
@@ -48,11 +48,6 @@ func TestSinglePageApplication(t *testing.T) {
 			Path:         "/endpoints/core_frontend",
 			ExpectedCode: http.StatusOK,
 		},
-		{ // XXX: Remove this in v4.0.0
-			Name:         "frontend-service",
-			Path:         "/services/core_frontend",
-			ExpectedCode: http.StatusOK,
-		},
 	}
 	for _, scenario := range scenarios {
 		t.Run(scenario.Name, func(t *testing.T) {

controller/handler/util.go

@@ -4,7 +4,7 @@ import (
 	"net/http"
 	"strconv"
 
-	"github.com/TwiN/gatus/v3/storage/store/common"
+	"github.com/TwiN/gatus/v4/storage/store/common"
 )
 
 const (

core/condition.go

@@ -6,8 +6,8 @@ import (
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/jsonpath"
+	"github.com/TwiN/gatus/v4/jsonpath"
-	"github.com/TwiN/gatus/v3/pattern"
+	"github.com/TwiN/gatus/v4/pattern"
 )
 
 const (
@@ -46,6 +46,9 @@ const (
 	// Values that could replace the placeholder: 4461677039 (~52 days)
 	CertificateExpirationPlaceholder = "[CERTIFICATE_EXPIRATION]"
 
+	// DomainExpirationPlaceholder is a placeholder for the duration before the domain expires, in milliseconds.
+	DomainExpirationPlaceholder = "[DOMAIN_EXPIRATION]"
+
 	// LengthFunctionPrefix is the prefix for the length function
 	//
 	// Usage: len([BODY].articles) == 10, len([BODY].name) > 5
@@ -142,9 +145,21 @@ func (c Condition) hasBodyPlaceholder() bool {
 	return strings.Contains(string(c), BodyPlaceholder)
 }
 
+// hasDomainExpirationPlaceholder checks whether the condition has a DomainExpirationPlaceholder
+// Used for determining whether a whois operation is necessary
+func (c Condition) hasDomainExpirationPlaceholder() bool {
+	return strings.Contains(string(c), DomainExpirationPlaceholder)
+}
+
+// hasIPPlaceholder checks whether the condition has an IPPlaceholder
+// Used for determining whether an IP lookup is necessary
+func (c Condition) hasIPPlaceholder() bool {
+	return strings.Contains(string(c), IPPlaceholder)
+}
+
 // isEqual compares two strings.
 //
-// Supports the pattern and the any functions.
+// Supports the "pat" and the "any" functions.
 // i.e. if one of the parameters starts with PatternFunctionPrefix and ends with FunctionSuffix, it will be treated like
 // a pattern.
 func isEqual(first, second string) bool {
@@ -219,6 +234,8 @@ func sanitizeAndResolve(elements []string, result *Result) ([]string, []string)
 			element = strconv.FormatBool(result.Connected)
 		case CertificateExpirationPlaceholder:
 			element = strconv.FormatInt(result.CertificateExpiration.Milliseconds(), 10)
+		case DomainExpirationPlaceholder:
+			element = strconv.FormatInt(result.DomainExpiration.Milliseconds(), 10)
 		default:
 			// if contains the BodyPlaceholder, then evaluate json path
 			if strings.Contains(element, BodyPlaceholder) {

core/dns_test.go

@@ -2,8 +2,9 @@ package core
 
 import (
 	"testing"
+	"time"
 
-	"github.com/TwiN/gatus/v3/pattern"
+	"github.com/TwiN/gatus/v4/pattern"
 )
 
 func TestIntegrationQuery(t *testing.T) {
@@ -21,7 +22,7 @@ func TestIntegrationQuery(t *testing.T) {
 				QueryType: "A",
 				QueryName: "example.com.",
 			},
-			inputURL:        "8.8.8.8",
+			inputURL:        "1.1.1.1",
 			expectedDNSCode: "NOERROR",
 			expectedBody:    "93.184.216.34",
 		},
@@ -31,7 +32,7 @@ func TestIntegrationQuery(t *testing.T) {
 				QueryType: "AAAA",
 				QueryName: "example.com.",
 			},
-			inputURL:        "8.8.8.8",
+			inputURL:        "1.1.1.1",
 			expectedDNSCode: "NOERROR",
 			expectedBody:    "2606:2800:220:1:248:1893:25c8:1946",
 		},
@@ -39,11 +40,11 @@ func TestIntegrationQuery(t *testing.T) {
 			name: "test DNS with type CNAME",
 			inputDNS: DNS{
 				QueryType: "CNAME",
-				QueryName: "doc.google.com.",
+				QueryName: "en.wikipedia.org.",
 			},
-			inputURL:        "8.8.8.8",
+			inputURL:        "1.1.1.1",
 			expectedDNSCode: "NOERROR",
-			expectedBody:    "writely.l.google.com.",
+			expectedBody:    "dyna.wikimedia.org.",
 		},
 		{
 			name: "test DNS with type MX",
@@ -51,7 +52,7 @@ func TestIntegrationQuery(t *testing.T) {
 				QueryType: "MX",
 				QueryName: "example.com.",
 			},
-			inputURL:        "8.8.8.8",
+			inputURL:        "1.1.1.1",
 			expectedDNSCode: "NOERROR",
 			expectedBody:    ".",
 		},
@@ -61,7 +62,7 @@ func TestIntegrationQuery(t *testing.T) {
 				QueryType: "NS",
 				QueryName: "example.com.",
 			},
-			inputURL:        "8.8.8.8",
+			inputURL:        "1.1.1.1",
 			expectedDNSCode: "NOERROR",
 			expectedBody:    "*.iana-servers.net.",
 		},
@@ -69,15 +70,14 @@ func TestIntegrationQuery(t *testing.T) {
 			name: "test DNS with fake type and retrieve error",
 			inputDNS: DNS{
 				QueryType: "B",
-				QueryName: "google",
+				QueryName: "example",
 			},
-			inputURL:      "8.8.8.8",
+			inputURL:      "1.1.1.1",
 			isErrExpected: true,
 		},
 	}
 
 	for _, test := range tests {
-		test := test
 		t.Run(test.name, func(t *testing.T) {
 			dns := test.inputDNS
 			result := &Result{}
@@ -86,9 +86,8 @@ func TestIntegrationQuery(t *testing.T) {
 				t.Errorf("there should be errors")
 			}
 			if result.DNSRCode != test.expectedDNSCode {
-				t.Errorf("DNSRCodePlaceholder '%s' should have been %s", result.DNSRCode, test.expectedDNSCode)
+				t.Errorf("expected DNSRCode to be %s, got %s", test.expectedDNSCode, result.DNSRCode)
 			}
-
 			if test.inputDNS.QueryType == "NS" {
 				// Because there are often multiple nameservers backing a single domain, we'll only look at the suffix
 				if !pattern.Match(test.expectedBody, string(result.body)) {
@@ -100,6 +99,7 @@ func TestIntegrationQuery(t *testing.T) {
 				}
 			}
 		})
+		time.Sleep(5 * time.Millisecond)
 	}
 }
 

core/endpoint.go

@@ -5,19 +5,22 @@ import (
 	"crypto/x509"
 	"encoding/json"
 	"errors"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
 	"strings"
 	"time"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/client"
+	"github.com/TwiN/gatus/v4/client"
-	"github.com/TwiN/gatus/v3/core/ui"
+	"github.com/TwiN/gatus/v4/core/ui"
-	"github.com/TwiN/gatus/v3/util"
+	"github.com/TwiN/gatus/v4/util"
+	"github.com/TwiN/whois"
 )
 
+type EndpointType string
+
 const (
 	// HostHeader is the name of the header used to specify the host
 	HostHeader = "Host"
@@ -30,6 +33,14 @@ const (
 
 	// GatusUserAgent is the default user agent that Gatus uses to send requests.
 	GatusUserAgent = "Gatus/1.0"
+
+	EndpointTypeDNS      EndpointType = "DNS"
+	EndpointTypeTCP      EndpointType = "TCP"
+	EndpointTypeICMP     EndpointType = "ICMP"
+	EndpointTypeSTARTTLS EndpointType = "STARTTLS"
+	EndpointTypeTLS      EndpointType = "TLS"
+	EndpointTypeHTTP     EndpointType = "HTTP"
+	EndpointTypeUNKNOWN  EndpointType = "UNKNOWN"
 )
 
 var (
@@ -41,6 +52,18 @@ var (
 
 	// ErrEndpointWithNoName is the error with which Gatus will panic if an endpoint is configured with no name
 	ErrEndpointWithNoName = errors.New("you must specify a name for each endpoint")
+
+	// ErrEndpointWithInvalidNameOrGroup is the error with which Gatus will panic if an endpoint has an invalid character where it shouldn't
+	ErrEndpointWithInvalidNameOrGroup = errors.New("endpoint name and group must not have \" or \\")
+
+	// ErrUnknownEndpointType is the error with which Gatus will panic if an endpoint has an unknown type
+	ErrUnknownEndpointType = errors.New("unknown endpoint type")
+
+	// ErrInvalidEndpointIntervalForDomainExpirationPlaceholder is the error with which Gatus will panic if an endpoint
+	// has both an interval smaller than 5 minutes and a condition with DomainExpirationPlaceholder.
+	// This is because the free whois service we are using should not be abused, especially considering the fact that
+	// the data takes a while to be updated.
+	ErrInvalidEndpointIntervalForDomainExpirationPlaceholder = errors.New("the minimum interval for an endpoint with a condition using the " + DomainExpirationPlaceholder + " placeholder is 300s (5m)")
 )
 
 // Endpoint is the configuration of a monitored
@@ -76,7 +99,7 @@ type Endpoint struct {
 	Interval time.Duration `yaml:"interval,omitempty"`
 
 	// Conditions used to determine the health of the endpoint
-	Conditions []*Condition `yaml:"conditions"`
+	Conditions []Condition `yaml:"conditions"`
 
 	// Alerts is the alerting configuration for the endpoint in case of failure
 	Alerts []*alert.Alert `yaml:"alerts,omitempty"`
@@ -102,16 +125,42 @@ func (endpoint Endpoint) IsEnabled() bool {
 	return *endpoint.Enabled
 }
 
-// ValidateAndSetDefaults validates the endpoint's configuration and sets the default value of fields that have one
+// Type returns the endpoint type
+func (endpoint Endpoint) Type() EndpointType {
+	switch {
+	case endpoint.DNS != nil:
+		return EndpointTypeDNS
+	case strings.HasPrefix(endpoint.URL, "tcp://"):
+		return EndpointTypeTCP
+	case strings.HasPrefix(endpoint.URL, "icmp://"):
+		return EndpointTypeICMP
+	case strings.HasPrefix(endpoint.URL, "starttls://"):
+		return EndpointTypeSTARTTLS
+	case strings.HasPrefix(endpoint.URL, "tls://"):
+		return EndpointTypeTLS
+	case strings.HasPrefix(endpoint.URL, "http://") || strings.HasPrefix(endpoint.URL, "https://"):
+		return EndpointTypeHTTP
+	default:
+		return EndpointTypeUNKNOWN
+	}
+}
+
+// ValidateAndSetDefaults validates the endpoint's configuration and sets the default value of args that have one
 func (endpoint *Endpoint) ValidateAndSetDefaults() error {
 	// Set default values
 	if endpoint.ClientConfig == nil {
 		endpoint.ClientConfig = client.GetDefaultConfig()
 	} else {
-		endpoint.ClientConfig.ValidateAndSetDefaults()
+		if err := endpoint.ClientConfig.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
 	}
 	if endpoint.UIConfig == nil {
 		endpoint.UIConfig = ui.GetDefaultConfig()
+	} else {
+		if err := endpoint.UIConfig.ValidateAndSetDefaults(); err != nil {
+			return err
+		}
 	}
 	if endpoint.Interval == 0 {
 		endpoint.Interval = 1 * time.Minute
@@ -132,25 +181,35 @@ func (endpoint *Endpoint) ValidateAndSetDefaults() error {
 		endpoint.Headers[ContentTypeHeader] = "application/json"
 	}
 	for _, endpointAlert := range endpoint.Alerts {
-		if endpointAlert.FailureThreshold <= 0 {
+		if err := endpointAlert.ValidateAndSetDefaults(); err != nil {
-			endpointAlert.FailureThreshold = 3
+			return err
-		}
-		if endpointAlert.SuccessThreshold <= 0 {
-			endpointAlert.SuccessThreshold = 2
 		}
 	}
 	if len(endpoint.Name) == 0 {
 		return ErrEndpointWithNoName
 	}
+	if strings.ContainsAny(endpoint.Name, "\"\\") || strings.ContainsAny(endpoint.Group, "\"\\") {
+		return ErrEndpointWithInvalidNameOrGroup
+	}
 	if len(endpoint.URL) == 0 {
 		return ErrEndpointWithNoURL
 	}
 	if len(endpoint.Conditions) == 0 {
 		return ErrEndpointWithNoCondition
 	}
+	if endpoint.Interval < 5*time.Minute {
+		for _, condition := range endpoint.Conditions {
+			if condition.hasDomainExpirationPlaceholder() {
+				return ErrInvalidEndpointIntervalForDomainExpirationPlaceholder
+			}
+		}
+	}
 	if endpoint.DNS != nil {
 		return endpoint.DNS.validateAndSetDefault()
 	}
+	if endpoint.Type() == EndpointTypeUNKNOWN {
+		return ErrUnknownEndpointType
+	}
 	// Make sure that the request can be created
 	_, err := http.NewRequest(endpoint.Method, endpoint.URL, bytes.NewBuffer([]byte(endpoint.Body)))
 	if err != nil {
@@ -159,6 +218,14 @@ func (endpoint *Endpoint) ValidateAndSetDefaults() error {
 	return nil
 }
 
+// DisplayName returns an identifier made up of the Name and, if not empty, the Group.
+func (endpoint Endpoint) DisplayName() string {
+	if len(endpoint.Group) > 0 {
+		return endpoint.Group + "/" + endpoint.Name
+	}
+	return endpoint.Name
+}
+
 // Key returns the unique key for the Endpoint
 func (endpoint Endpoint) Key() string {
 	return util.ConvertGroupAndEndpointNameToKey(endpoint.Group, endpoint.Name)
@@ -167,7 +234,26 @@ func (endpoint Endpoint) Key() string {
 // EvaluateHealth sends a request to the endpoint's URL and evaluates the conditions of the endpoint.
 func (endpoint *Endpoint) EvaluateHealth() *Result {
 	result := &Result{Success: true, Errors: []string{}}
+	// Parse or extract hostname from URL
+	if endpoint.DNS != nil {
+		result.Hostname = strings.TrimSuffix(endpoint.URL, ":53")
+	} else {
+		urlObject, err := url.Parse(endpoint.URL)
+		if err != nil {
+			result.AddError(err.Error())
+		} else {
+			result.Hostname = urlObject.Hostname()
+		}
+	}
+	// Retrieve IP if necessary
+	if endpoint.needsToRetrieveIP() {
 		endpoint.getIP(result)
+	}
+	// Retrieve domain expiration if necessary
+	if endpoint.needsToRetrieveDomainExpiration() && len(result.Hostname) > 0 {
+		endpoint.getDomainExpiration(result)
+	}
+	//
 	if len(result.Errors) == 0 {
 		endpoint.call(result)
 	} else {
@@ -183,23 +269,21 @@ func (endpoint *Endpoint) EvaluateHealth() *Result {
 	// No need to keep the body after the endpoint has been evaluated
 	result.body = nil
 	// Clean up parameters that we don't need to keep in the results
+	if endpoint.UIConfig.HideURL {
+		for errIdx, errorString := range result.Errors {
+			result.Errors[errIdx] = strings.ReplaceAll(errorString, endpoint.URL, "<redacted>")
+		}
+	}
 	if endpoint.UIConfig.HideHostname {
+		for errIdx, errorString := range result.Errors {
+			result.Errors[errIdx] = strings.ReplaceAll(errorString, result.Hostname, "<redacted>")
+		}
 		result.Hostname = ""
 	}
 	return result
 }
 
 func (endpoint *Endpoint) getIP(result *Result) {
-	if endpoint.DNS != nil {
-		result.Hostname = strings.TrimSuffix(endpoint.URL, ":53")
-	} else {
-		urlObject, err := url.Parse(endpoint.URL)
-		if err != nil {
-			result.AddError(err.Error())
-			return
-		}
-		result.Hostname = urlObject.Hostname()
-	}
 	ips, err := net.LookupIP(result.Hostname)
 	if err != nil {
 		result.AddError(err.Error())
@@ -208,26 +292,30 @@ func (endpoint *Endpoint) getIP(result *Result) {
 	result.IP = ips[0].String()
 }
 
+func (endpoint *Endpoint) getDomainExpiration(result *Result) {
+	whoisClient := whois.NewClient()
+	if whoisResponse, err := whoisClient.QueryAndParse(result.Hostname); err != nil {
+		result.AddError("error querying and parsing hostname using whois client: " + err.Error())
+	} else {
+		result.DomainExpiration = time.Until(whoisResponse.ExpirationDate)
+	}
+}
+
 func (endpoint *Endpoint) call(result *Result) {
 	var request *http.Request
 	var response *http.Response
 	var err error
 	var certificate *x509.Certificate
-	isTypeDNS := endpoint.DNS != nil
+	endpointType := endpoint.Type()
-	isTypeTCP := strings.HasPrefix(endpoint.URL, "tcp://")
+	if endpointType == EndpointTypeHTTP {
-	isTypeICMP := strings.HasPrefix(endpoint.URL, "icmp://")
-	isTypeSTARTTLS := strings.HasPrefix(endpoint.URL, "starttls://")
-	isTypeTLS := strings.HasPrefix(endpoint.URL, "tls://")
-	isTypeHTTP := !isTypeDNS && !isTypeTCP && !isTypeICMP && !isTypeSTARTTLS && !isTypeTLS
-	if isTypeHTTP {
 		request = endpoint.buildHTTPRequest()
 	}
 	startTime := time.Now()
-	if isTypeDNS {
+	if endpointType == EndpointTypeDNS {
 		endpoint.DNS.query(endpoint.URL, result)
 		result.Duration = time.Since(startTime)
-	} else if isTypeSTARTTLS || isTypeTLS {
+	} else if endpointType == EndpointTypeSTARTTLS || endpointType == EndpointTypeTLS {
-		if isTypeSTARTTLS {
+		if endpointType == EndpointTypeSTARTTLS {
 			result.Connected, certificate, err = client.CanPerformStartTLS(strings.TrimPrefix(endpoint.URL, "starttls://"), endpoint.ClientConfig)
 		} else {
 			result.Connected, certificate, err = client.CanPerformTLS(strings.TrimPrefix(endpoint.URL, "tls://"), endpoint.ClientConfig)
@@ -238,10 +326,10 @@ func (endpoint *Endpoint) call(result *Result) {
 		}
 		result.Duration = time.Since(startTime)
 		result.CertificateExpiration = time.Until(certificate.NotAfter)
-	} else if isTypeTCP {
+	} else if endpointType == EndpointTypeTCP {
 		result.Connected = client.CanCreateTCPConnection(strings.TrimPrefix(endpoint.URL, "tcp://"), endpoint.ClientConfig)
 		result.Duration = time.Since(startTime)
-	} else if isTypeICMP {
+	} else if endpointType == EndpointTypeICMP {
 		result.Connected, result.Duration = client.Ping(strings.TrimPrefix(endpoint.URL, "icmp://"), endpoint.ClientConfig)
 	} else {
 		response, err = client.GetHTTPClient(endpoint.ClientConfig).Do(request)
@@ -259,9 +347,9 @@ func (endpoint *Endpoint) call(result *Result) {
 		result.Connected = response.StatusCode > 0
 		// Only read the body if there's a condition that uses the BodyPlaceholder
 		if endpoint.needsToReadBody() {
-			result.body, err = ioutil.ReadAll(response.Body)
+			result.body, err = io.ReadAll(response.Body)
 			if err != nil {
-				result.AddError(err.Error())
+				result.AddError("error reading response body:" + err.Error())
 			}
 		}
 	}
@@ -288,7 +376,7 @@ func (endpoint *Endpoint) buildHTTPRequest() *http.Request {
 	return request
 }
 
-// needsToReadBody checks if there's any conditions that requires the response body to be read
+// needsToReadBody checks if there's any condition that requires the response body to be read
 func (endpoint *Endpoint) needsToReadBody() bool {
 	for _, condition := range endpoint.Conditions {
 		if condition.hasBodyPlaceholder() {
@@ -297,3 +385,23 @@ func (endpoint *Endpoint) needsToReadBody() bool {
 	}
 	return false
 }
+
+// needsToRetrieveDomainExpiration checks if there's any condition that requires a whois query to be performed
+func (endpoint *Endpoint) needsToRetrieveDomainExpiration() bool {
+	for _, condition := range endpoint.Conditions {
+		if condition.hasDomainExpirationPlaceholder() {
+			return true
+		}
+	}
+	return false
+}
+
+// needsToRetrieveIP checks if there's any condition that requires an IP lookup
+func (endpoint *Endpoint) needsToRetrieveIP() bool {
+	for _, condition := range endpoint.Conditions {
+		if condition.hasIPPlaceholder() {
+			return true
+		}
+	}
+	return false
+}

core/endpoint_status.go

@@ -1,6 +1,6 @@
 package core
 
-import "github.com/TwiN/gatus/v3/util"
+import "github.com/TwiN/gatus/v4/util"
 
 // EndpointStatus contains the evaluation Results of an Endpoint
 type EndpointStatus struct {

core/endpoint_test.go

@@ -1,15 +1,245 @@
 package core
 
 import (
-	"io/ioutil"
+	"bytes"
+	"crypto/tls"
+	"crypto/x509"
+	"io"
+	"net/http"
 	"strings"
 	"testing"
 	"time"
 
-	"github.com/TwiN/gatus/v3/alerting/alert"
+	"github.com/TwiN/gatus/v4/alerting/alert"
-	"github.com/TwiN/gatus/v3/client"
+	"github.com/TwiN/gatus/v4/client"
+	"github.com/TwiN/gatus/v4/core/ui"
+	"github.com/TwiN/gatus/v4/test"
 )
 
+func TestEndpoint(t *testing.T) {
+	defer client.InjectHTTPClient(nil)
+	scenarios := []struct {
+		Name             string
+		Endpoint         Endpoint
+		ExpectedResult   *Result
+		MockRoundTripper test.MockRoundTripper
+	}{
+		{
+			Name: "success",
+			Endpoint: Endpoint{
+				Name:       "website-health",
+				URL:        "https://twin.sh/health",
+				Conditions: []Condition{"[STATUS] == 200", "[BODY].status == UP", "[CERTIFICATE_EXPIRATION] > 24h"},
+			},
+			ExpectedResult: &Result{
+				Success:   true,
+				Connected: true,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					{Condition: "[STATUS] == 200", Success: true},
+					{Condition: "[BODY].status == UP", Success: true},
+					{Condition: "[CERTIFICATE_EXPIRATION] > 24h", Success: true},
+				},
+				DomainExpiration: 0, // Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+			},
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"status": "UP"}`)),
+					TLS:        &tls.ConnectionState{PeerCertificates: []*x509.Certificate{{NotAfter: time.Now().Add(9999 * time.Hour)}}},
+				}
+			}),
+		},
+		{
+			Name: "failed-body-condition",
+			Endpoint: Endpoint{
+				Name:       "website-health",
+				URL:        "https://twin.sh/health",
+				Conditions: []Condition{"[STATUS] == 200", "[BODY].status == UP"},
+			},
+			ExpectedResult: &Result{
+				Success:   false,
+				Connected: true,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					{Condition: "[STATUS] == 200", Success: true},
+					{Condition: "[BODY].status (DOWN) == UP", Success: false},
+				},
+				DomainExpiration: 0, // Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+			},
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(bytes.NewBufferString(`{"status": "DOWN"}`))}
+			}),
+		},
+		{
+			Name: "failed-status-condition",
+			Endpoint: Endpoint{
+				Name:       "website-health",
+				URL:        "https://twin.sh/health",
+				Conditions: []Condition{"[STATUS] == 200"},
+			},
+			ExpectedResult: &Result{
+				Success:   false,
+				Connected: true,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					{Condition: "[STATUS] (502) == 200", Success: false},
+				},
+				DomainExpiration: 0, // Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+			},
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusBadGateway, Body: http.NoBody}
+			}),
+		},
+		{
+			Name: "condition-with-failed-certificate-expiration",
+			Endpoint: Endpoint{
+				Name:       "website-health",
+				URL:        "https://twin.sh/health",
+				Conditions: []Condition{"[CERTIFICATE_EXPIRATION] > 100h"},
+				UIConfig:   &ui.Config{DontResolveFailedConditions: true},
+			},
+			ExpectedResult: &Result{
+				Success:   false,
+				Connected: true,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					// Because UIConfig.DontResolveFailedConditions is true, the values in the condition should not be resolved
+					{Condition: "[CERTIFICATE_EXPIRATION] > 100h", Success: false},
+				},
+				DomainExpiration: 0, // Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+			},
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{
+					StatusCode: http.StatusOK,
+					Body:       http.NoBody,
+					TLS:        &tls.ConnectionState{PeerCertificates: []*x509.Certificate{{NotAfter: time.Now().Add(5 * time.Hour)}}},
+				}
+			}),
+		},
+		{
+			Name: "domain-expiration",
+			Endpoint: Endpoint{
+				Name:       "website-health",
+				URL:        "https://twin.sh/health",
+				Conditions: []Condition{"[DOMAIN_EXPIRATION] > 100h"},
+			},
+			ExpectedResult: &Result{
+				Success:   true,
+				Connected: true,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					{Condition: "[DOMAIN_EXPIRATION] > 100h", Success: true},
+				},
+				DomainExpiration: 999999 * time.Hour, // Note that this test only checks if it's non-zero.
+			},
+			MockRoundTripper: test.MockRoundTripper(func(r *http.Request) *http.Response {
+				return &http.Response{StatusCode: http.StatusOK, Body: http.NoBody}
+			}),
+		},
+		{
+			Name: "endpoint-that-will-time-out-and-hidden-hostname",
+			Endpoint: Endpoint{
+				Name:         "endpoint-that-will-time-out",
+				URL:          "https://twin.sh/health",
+				Conditions:   []Condition{"[CONNECTED] == true"},
+				UIConfig:     &ui.Config{HideHostname: true},
+				ClientConfig: &client.Config{Timeout: time.Millisecond},
+			},
+			ExpectedResult: &Result{
+				Success:   false,
+				Connected: false,
+				Hostname:  "", // Because Endpoint.UIConfig.HideHostname is true, this should be empty.
+				ConditionResults: []*ConditionResult{
+					{Condition: "[CONNECTED] (false) == true", Success: false},
+				},
+				// Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+				DomainExpiration: 0,
+				// Because Endpoint.UIConfig.HideHostname is true, the hostname should be replaced by <redacted>.
+				Errors: []string{`Get "https://<redacted>/health": context deadline exceeded (Client.Timeout exceeded while awaiting headers)`},
+			},
+			MockRoundTripper: nil,
+		},
+		{
+			Name: "endpoint-that-will-time-out-and-hidden-url",
+			Endpoint: Endpoint{
+				Name:         "endpoint-that-will-time-out",
+				URL:          "https://twin.sh/health",
+				Conditions:   []Condition{"[CONNECTED] == true"},
+				UIConfig:     &ui.Config{HideURL: true},
+				ClientConfig: &client.Config{Timeout: time.Millisecond},
+			},
+			ExpectedResult: &Result{
+				Success:   false,
+				Connected: false,
+				Hostname:  "twin.sh",
+				ConditionResults: []*ConditionResult{
+					{Condition: "[CONNECTED] (false) == true", Success: false},
+				},
+				// Because there's no [DOMAIN_EXPIRATION] condition, this is not resolved, so it should be 0.
+				DomainExpiration: 0,
+				// Because Endpoint.UIConfig.HideURL is true, the URL should be replaced by <redacted>.
+				Errors: []string{`Get "<redacted>": context deadline exceeded (Client.Timeout exceeded while awaiting headers)`},
+			},
+			MockRoundTripper: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.Name, func(t *testing.T) {
+			if scenario.MockRoundTripper != nil {
+				mockClient := &http.Client{Transport: scenario.MockRoundTripper}
+				if scenario.Endpoint.ClientConfig != nil && scenario.Endpoint.ClientConfig.Timeout > 0 {
+					mockClient.Timeout = scenario.Endpoint.ClientConfig.Timeout
+				}
+				client.InjectHTTPClient(mockClient)
+			} else {
+				client.InjectHTTPClient(nil)
+			}
+			scenario.Endpoint.ValidateAndSetDefaults()
+			result := scenario.Endpoint.EvaluateHealth()
+			if result.Success != scenario.ExpectedResult.Success {
+				t.Errorf("Expected success to be %v, got %v", scenario.ExpectedResult.Success, result.Success)
+			}
+			if result.Connected != scenario.ExpectedResult.Connected {
+				t.Errorf("Expected connected to be %v, got %v", scenario.ExpectedResult.Connected, result.Connected)
+			}
+			if result.Hostname != scenario.ExpectedResult.Hostname {
+				t.Errorf("Expected hostname to be %v, got %v", scenario.ExpectedResult.Hostname, result.Hostname)
+			}
+			if len(result.ConditionResults) != len(scenario.ExpectedResult.ConditionResults) {
+				t.Errorf("Expected %v condition results, got %v", len(scenario.ExpectedResult.ConditionResults), len(result.ConditionResults))
+			} else {
+				for i, conditionResult := range result.ConditionResults {
+					if conditionResult.Condition != scenario.ExpectedResult.ConditionResults[i].Condition {
+						t.Errorf("Expected condition to be %v, got %v", scenario.ExpectedResult.ConditionResults[i].Condition, conditionResult.Condition)
+					}
+					if conditionResult.Success != scenario.ExpectedResult.ConditionResults[i].Success {
+						t.Errorf("Expected success of condition '%s' to be %v, got %v", conditionResult.Condition, scenario.ExpectedResult.ConditionResults[i].Success, conditionResult.Success)
+					}
+				}
+			}
+			if len(result.Errors) != len(scenario.ExpectedResult.Errors) {
+				t.Errorf("Expected %v errors, got %v", len(scenario.ExpectedResult.Errors), len(result.Errors))
+			} else {
+				for i, err := range result.Errors {
+					if err != scenario.ExpectedResult.Errors[i] {
+						t.Errorf("Expected error to be %v, got %v", scenario.ExpectedResult.Errors[i], err)
+					}
+				}
+			}
+			if result.DomainExpiration != scenario.ExpectedResult.DomainExpiration {
+				// Note that DomainExpiration is only resolved if there's a condition with the DomainExpirationPlaceholder in it.
+				// In other words, if there's no condition with [DOMAIN_EXPIRATION] in it, the DomainExpiration field will be 0.
+				// Because this is a live call, mocking it would be too much of a pain, so we're just going to check if
+				// the actual value is non-zero when the expected result is non-zero.
+				if scenario.ExpectedResult.DomainExpiration.Hours() > 0 && !(result.DomainExpiration.Hours() > 0) {
+					t.Errorf("Expected domain expiration to be non-zero, got %v", result.DomainExpiration)
+				}
+			}
+		})
+	}
+}
+
 func TestEndpoint_IsEnabled(t *testing.T) {
 	if !(Endpoint{Enabled: nil}).IsEnabled() {
 		t.Error("endpoint.IsEnabled() should've returned true, because Enabled was set to nil")
@@ -22,12 +252,86 @@ func TestEndpoint_IsEnabled(t *testing.T) {
 	}
 }
 
+func TestEndpoint_Type(t *testing.T) {
+	type args struct {
+		URL string
+		DNS *DNS
+	}
+	tests := []struct {
+		args args
+		want EndpointType
+	}{
+		{
+			args: args{
+				URL: "1.1.1.1",
+				DNS: &DNS{
+					QueryType: "A",
+					QueryName: "example.com",
+				},
+			},
+			want: EndpointTypeDNS,
+		},
+		{
+			args: args{
+				URL: "tcp://127.0.0.1:6379",
+			},
+			want: EndpointTypeTCP,
+		},
+		{
+			args: args{
+				URL: "icmp://example.com",
+			},
+			want: EndpointTypeICMP,
+		},
+		{
+			args: args{
+				URL: "starttls://smtp.gmail.com:587",
+			},
+			want: EndpointTypeSTARTTLS,
+		},
+		{
+			args: args{
+				URL: "tls://example.com:443",
+			},
+			want: EndpointTypeTLS,
+		},
+		{
+			args: args{
+				URL: "https://twin.sh/health",
+			},
+			want: EndpointTypeHTTP,
+		},
+		{
+			args: args{
+				URL: "invalid://example.org",
+			},
+			want: EndpointTypeUNKNOWN,
+		},
+		{
+			args: args{
+				URL: "no-scheme",
+			},
+			want: EndpointTypeUNKNOWN,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(string(tt.want), func(t *testing.T) {
+			endpoint := Endpoint{
+				URL: tt.args.URL,
+				DNS: tt.args.DNS,
+			}
+			if got := endpoint.Type(); got != tt.want {
+				t.Errorf("Endpoint.Type() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
 func TestEndpoint_ValidateAndSetDefaults(t *testing.T) {
-	condition := Condition("[STATUS] == 200")
 	endpoint := Endpoint{
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{Condition("[STATUS] == 200")},
 		Alerts:     []*alert.Alert{{Type: alert.TypePagerDuty}},
 	}
 	endpoint.ValidateAndSetDefaults()
@@ -68,11 +372,10 @@ func TestEndpoint_ValidateAndSetDefaults(t *testing.T) {
 }
 
 func TestEndpoint_ValidateAndSetDefaultsWithClientConfig(t *testing.T) {
-	condition := Condition("[STATUS] == 200")
 	endpoint := Endpoint{
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{Condition("[STATUS] == 200")},
 		ClientConfig: &client.Config{
 			Insecure:       true,
 			IgnoreRedirect: true,
@@ -95,73 +398,88 @@ func TestEndpoint_ValidateAndSetDefaultsWithClientConfig(t *testing.T) {
 	}
 }
 
-func TestEndpoint_ValidateAndSetDefaultsWithNoName(t *testing.T) {
-	defer func() { recover() }()
-	condition := Condition("[STATUS] == 200")
-	endpoint := &Endpoint{
-		Name:       "",
-		URL:        "http://example.com",
-		Conditions: []*Condition{&condition},
-	}
-	err := endpoint.ValidateAndSetDefaults()
-	if err == nil {
-		t.Fatal("Should've returned an error because endpoint didn't have a name, which is a mandatory field")
-	}
-}
-
-func TestEndpoint_ValidateAndSetDefaultsWithNoUrl(t *testing.T) {
-	defer func() { recover() }()
-	condition := Condition("[STATUS] == 200")
-	endpoint := &Endpoint{
-		Name:       "example",
-		URL:        "",
-		Conditions: []*Condition{&condition},
-	}
-	err := endpoint.ValidateAndSetDefaults()
-	if err == nil {
-		t.Fatal("Should've returned an error because endpoint didn't have an url, which is a mandatory field")
-	}
-}
-
-func TestEndpoint_ValidateAndSetDefaultsWithNoConditions(t *testing.T) {
-	defer func() { recover() }()
-	endpoint := &Endpoint{
-		Name:       "example",
-		URL:        "http://example.com",
-		Conditions: nil,
-	}
-	err := endpoint.ValidateAndSetDefaults()
-	if err == nil {
-		t.Fatal("Should've returned an error because endpoint didn't have at least 1 condition")
-	}
-}
-
 func TestEndpoint_ValidateAndSetDefaultsWithDNS(t *testing.T) {
-	conditionSuccess := Condition("[DNS_RCODE] == NOERROR")
 	endpoint := &Endpoint{
 		Name: "dns-test",
-		URL:  "http://example.com",
+		URL:  "https://example.com",
 		DNS: &DNS{
 			QueryType: "A",
 			QueryName: "example.com",
 		},
-		Conditions: []*Condition{&conditionSuccess},
+		Conditions: []Condition{Condition("[DNS_RCODE] == NOERROR")},
 	}
 	err := endpoint.ValidateAndSetDefaults()
 	if err != nil {
-
+		t.Error("did not expect an error, got", err)
 	}
 	if endpoint.DNS.QueryName != "example.com." {
 		t.Error("Endpoint.dns.query-name should be formatted with . suffix")
 	}
 }
 
+func TestEndpoint_ValidateAndSetDefaultsWithSimpleErrors(t *testing.T) {
+	scenarios := []struct {
+		endpoint    *Endpoint
+		expectedErr error
+	}{
+		{
+			endpoint: &Endpoint{
+				Name:       "",
+				URL:        "https://example.com",
+				Conditions: []Condition{Condition("[STATUS] == 200")},
+			},
+			expectedErr: ErrEndpointWithNoName,
+		},
+		{
+			endpoint: &Endpoint{
+				Name:       "endpoint-with-no-url",
+				URL:        "",
+				Conditions: []Condition{Condition("[STATUS] == 200")},
+			},
+			expectedErr: ErrEndpointWithNoURL,
+		},
+		{
+			endpoint: &Endpoint{
+				Name:       "endpoint-with-no-conditions",
+				URL:        "https://example.com",
+				Conditions: nil,
+			},
+			expectedErr: ErrEndpointWithNoCondition,
+		},
+		{
+			endpoint: &Endpoint{
+				Name:       "domain-expiration-with-bad-interval",
+				URL:        "https://example.com",
+				Interval:   time.Minute,
+				Conditions: []Condition{Condition("[DOMAIN_EXPIRATION] > 720h")},
+			},
+			expectedErr: ErrInvalidEndpointIntervalForDomainExpirationPlaceholder,
+		},
+		{
+			endpoint: &Endpoint{
+				Name:       "domain-expiration-with-good-interval",
+				URL:        "https://example.com",
+				Interval:   5 * time.Minute,
+				Conditions: []Condition{Condition("[DOMAIN_EXPIRATION] > 720h")},
+			},
+			expectedErr: nil,
+		},
+	}
+	for _, scenario := range scenarios {
+		t.Run(scenario.endpoint.Name, func(t *testing.T) {
+			if err := scenario.endpoint.ValidateAndSetDefaults(); err != scenario.expectedErr {
+				t.Errorf("Expected error %v, got %v", scenario.expectedErr, err)
+			}
+		})
+	}
+}
+
 func TestEndpoint_buildHTTPRequest(t *testing.T) {
 	condition := Condition("[STATUS] == 200")
 	endpoint := Endpoint{
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{condition},
 	}
 	endpoint.ValidateAndSetDefaults()
 	request := endpoint.buildHTTPRequest()
@@ -181,7 +499,7 @@ func TestEndpoint_buildHTTPRequestWithCustomUserAgent(t *testing.T) {
 	endpoint := Endpoint{
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{condition},
 		Headers: map[string]string{
 			"User-Agent": "Test/2.0",
 		},
@@ -205,7 +523,7 @@ func TestEndpoint_buildHTTPRequestWithHostHeader(t *testing.T) {
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
 		Method:     "POST",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{condition},
 		Headers: map[string]string{
 			"Host": "example.com",
 		},
@@ -226,7 +544,7 @@ func TestEndpoint_buildHTTPRequestWithGraphQLEnabled(t *testing.T) {
 		Name:       "website-graphql",
 		URL:        "https://twin.sh/graphql",
 		Method:     "POST",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{condition},
 		GraphQL:    true,
 		Body: `{
   users(gender: "female") {
@@ -245,7 +563,7 @@ func TestEndpoint_buildHTTPRequestWithGraphQLEnabled(t *testing.T) {
 	if contentType := request.Header.Get(ContentTypeHeader); contentType != "application/json" {
 		t.Error("request.Header.Content-Type should've been application/json, but was", contentType)
 	}
-	body, _ := ioutil.ReadAll(request.Body)
+	body, _ := io.ReadAll(request.Body)
 	if !strings.HasPrefix(string(body), "{\"query\":") {
 		t.Error("request.body should've started with '{\"query\":', but it didn't:", string(body))
 	}
@@ -257,7 +575,7 @@ func TestIntegrationEvaluateHealth(t *testing.T) {
 	endpoint := Endpoint{
 		Name:       "website-health",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition, &bodyCondition},
+		Conditions: []Condition{condition, bodyCondition},
 	}
 	endpoint.ValidateAndSetDefaults()
 	result := endpoint.EvaluateHealth()
@@ -270,25 +588,53 @@ func TestIntegrationEvaluateHealth(t *testing.T) {
 	if !result.Success {
 		t.Error("Because all conditions passed, this should have been a success")
 	}
+	if result.Hostname != "twin.sh" {
+		t.Error("result.Hostname should've been twin.sh, but was", result.Hostname)
+	}
 }
 
-func TestIntegrationEvaluateHealthWithFailure(t *testing.T) {
+func TestIntegrationEvaluateHealthWithInvalidCondition(t *testing.T) {
-	condition := Condition("[STATUS] == 500")
+	condition := Condition("[STATUS] invalid 200")
 	endpoint := Endpoint{
-		Name:       "website-health",
+		Name:       "invalid-condition",
 		URL:        "https://twin.sh/health",
-		Conditions: []*Condition{&condition},
+		Conditions: []Condition{condition},
+	}
+	if err := endpoint.ValidateAndSetDefaults(); err != nil {
+		// XXX: Should this really not return an error? After all, the condition is not valid and conditions are part of the endpoint...
+		t.Error("endpoint validation should've been successful, but wasn't")
+	}
+	result := endpoint.EvaluateHealth()
+	if result.Success {
+		t.Error("Because one of the conditions was invalid, result.Success should have been false")
+	}
+	if len(result.Errors) == 0 {
+		t.Error("There should've been an error")
+	}
+}
+
+func TestIntegrationEvaluateHealthWithErrorAndHideURL(t *testing.T) {
+	endpoint := Endpoint{
+		Name:       "invalid-url",
+		URL:        "https://httpstat.us/200?sleep=100",
+		Conditions: []Condition{Condition("[STATUS] == 200")},
+		ClientConfig: &client.Config{
+			Timeout: 1 * time.Millisecond,
+		},
+		UIConfig: &ui.Config{
+			HideURL: true,
+		},
 	}
 	endpoint.ValidateAndSetDefaults()
 	result := endpoint.EvaluateHealth()
-	if result.ConditionResults[0].Success {
-		t.Errorf("Condition '%s' should have been a failure", condition)
-	}
-	if !result.Connected {
-		t.Error("Because the connection has been established, result.Connected should've been true")
-	}
 	if result.Success {
-		t.Error("Because one of the conditions failed, success should have been false")
+		t.Error("Because one of the conditions was invalid, result.Success should have been false")
+	}
+	if len(result.Errors) == 0 {
+		t.Error("There should've been an error")
+	}
+	if !strings.Contains(result.Errors[0], "<redacted>") || strings.Contains(result.Errors[0], endpoint.URL) {
+		t.Error("result.Errors[0] should've had the URL redacted because ui.hide-url is set to true")
 	}
 }
 
@@ -297,17 +643,17 @@ func TestIntegrationEvaluateHealthForDNS(t *testing.T) {
 	conditionBody := Condition("[BODY] == 93.184.216.34")
 	endpoint := Endpoint{
 		Name: "example",
-		URL:  "8.8.8.8",
+		URL:  "1.1.1.1",
 		DNS: &DNS{
 			QueryType: "A",
 			QueryName: "example.com.",
 		},
-		Conditions: []*Condition{&conditionSuccess, &conditionBody},
+		Conditions: []Condition{conditionSuccess, conditionBody},
 	}
 	endpoint.ValidateAndSetDefaults()
 	result := endpoint.EvaluateHealth()
 	if !result.ConditionResults[0].Success {
-		t.Errorf("Conditions '%s' and %s should have been a success", conditionSuccess, conditionBody)
+		t.Errorf("Conditions '%s' and '%s' should have been a success", conditionSuccess, conditionBody)
 	}
 	if !result.Connected {
 		t.Error("Because the connection has been established, result.Connected should've been true")
@@ -318,16 +664,15 @@ func TestIntegrationEvaluateHealthForDNS(t *testing.T) {
 }
 
 func TestIntegrationEvaluateHealthForICMP(t *testing.T) {
-	conditionSuccess := Condition("[CONNECTED] == true")
 	endpoint := Endpoint{
 		Name:       "icmp-test",
 		URL:        "icmp://127.0.0.1",
-		Conditions: []*Condition{&conditionSuccess},
+		Conditions: []Condition{"[CONNECTED] == true"},
 	}
 	endpoint.ValidateAndSetDefaults()
 	result := endpoint.EvaluateHealth()
 	if !result.ConditionResults[0].Success {
-		t.Errorf("Conditions '%s' should have been a success", conditionSuccess)
+		t.Errorf("Conditions '%s' should have been a success", endpoint.Conditions[0])
 	}
 	if !result.Connected {
 		t.Error("Because the connection has been established, result.Connected should've been true")
@@ -337,12 +682,20 @@ func TestIntegrationEvaluateHealthForICMP(t *testing.T) {
 	}
 }
 
+func TestEndpoint_DisplayName(t *testing.T) {
+	if endpoint := (Endpoint{Name: "n"}); endpoint.DisplayName() != "n" {
+		t.Error("endpoint.DisplayName() should've been 'n', but was", endpoint.DisplayName())
+	}
+	if endpoint := (Endpoint{Group: "g", Name: "n"}); endpoint.DisplayName() != "g/n" {
+		t.Error("endpoint.DisplayName() should've been 'g/n', but was", endpoint.DisplayName())
+	}
+}
+
 func TestEndpoint_getIP(t *testing.T) {
-	conditionSuccess := Condition("[CONNECTED] == true")
 	endpoint := Endpoint{
 		Name:       "invalid-url-test",
 		URL:        "",
-		Conditions: []*Condition{&conditionSuccess},
+		Conditions: []Condition{"[CONNECTED] == true"},
 	}
 	result := &Result{}
 	endpoint.getIP(result)
@@ -351,26 +704,44 @@ func TestEndpoint_getIP(t *testing.T) {
 	}
 }
 
-func TestEndpoint_NeedsToReadBody(t *testing.T) {
+func TestEndpoint_needsToReadBody(t *testing.T) {
 	statusCondition := Condition("[STATUS] == 200")
 	bodyCondition := Condition("[BODY].status == UP")
 	bodyConditionWithLength := Condition("len([BODY].tags) > 0")
-	if (&Endpoint{Conditions: []*Condition{&statusCondition}}).needsToReadBody() {
+	if (&Endpoint{Conditions: []Condition{statusCondition}}).needsToReadBody() {
 		t.Error("expected false, got true")
 	}
-	if !(&Endpoint{Conditions: []*Condition{&bodyCondition}}).needsToReadBody() {
+	if !(&Endpoint{Conditions: []Condition{bodyCondition}}).needsToReadBody() {
 		t.Error("expected true, got false")
 	}
-	if !(&Endpoint{Conditions: []*Condition{&bodyConditionWithLength}}).needsToReadBody() {
+	if !(&Endpoint{Conditions: []Condition{bodyConditionWithLength}}).needsToReadBody() {
 		t.Error("expected true, got false")
 	}
-	if !(&Endpoint{Conditions: []*Condition{&statusCondition, &bodyCondition}}).needsToReadBody() {
+	if !(&Endpoint{Conditions: []Condition{statusCondition, bodyCondition}}).needsToReadBody() {
 		t.Error("expected true, got false")
 	}
-	if !(&Endpoint{Conditions: []*Condition{&bodyCondition, &statusCondition}}).needsToReadBody() {
+	if !(&Endpoint{Conditions: []Condition{bodyCondition, statusCondition}}).needsToReadBody() {
 		t.Error("expected true, got false")
 	}
-	if !(&Endpoint{Conditions: []*Condition{&bodyConditionWithLength, &statusCondition}}).needsToReadBody() {
+	if !(&Endpoint{Conditions: []Condition{bodyConditionWithLength, statusCondition}}).needsToReadBody() {
+		t.Error("expected true, got false")
+	}
+}
+
+func TestEndpoint_needsToRetrieveDomainExpiration(t *testing.T) {
+	if (&Endpoint{Conditions: []Condition{"[STATUS] == 200"}}).needsToRetrieveDomainExpiration() {
+		t.Error("expected false, got true")
+	}
+	if !(&Endpoint{Conditions: []Condition{"[STATUS] == 200", "[DOMAIN_EXPIRATION] < 720h"}}).needsToRetrieveDomainExpiration() {
+		t.Error("expected true, got false")
+	}
+}
+
+func TestEndpoint_needsToRetrieveIP(t *testing.T) {
+	if (&Endpoint{Conditions: []Condition{"[STATUS] == 200"}}).needsToRetrieveIP() {
+		t.Error("expected false, got true")
+	}
+	if !(&Endpoint{Conditions: []Condition{"[STATUS] == 200", "[IP] == 127.0.0.1"}}).needsToRetrieveIP() {
 		t.Error("expected true, got false")
 	}
 }