feat(client): Allow configuration of client cookie storage (#1716)

* Allow configuration of cookie storage

* Update client/config.go

---------

Co-authored-by: TwiN <twin@linux.com>

README.md

@@ -654,6 +654,7 @@ the client used to send the request.
 | `client.tls.renegotiation`             | Type of renegotiation support to provide. (`never`, `freely`, `once`).        | `"never"`       |
 | `client.network`                       | The network to use for ICMP endpoint client (`ip`, `ip4` or `ip6`).           | `"ip"`          |
 | `client.tunnel`                        | Name of the SSH tunnel to use for this endpoint. See [Tunneling](#tunneling). | `""`            |
+| `client.store-cookies`                 | Whether to store cookies between requests.                                    | `false`         |
 
 
 > 📝 Some of these parameters are ignored based on the type of endpoint. For instance, there's no certificate involved
@@ -666,6 +667,7 @@ client:
   insecure: false
   ignore-redirect: false
   timeout: 10s
+  store-cookies: false
 ```
 
 Note that this configuration is only available under `endpoints[]`, `alerting.mattermost` and `alerting.custom`.

client/config.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"net"
 	"net/http"
+	"net/http/cookiejar"
 	"net/url"
 	"regexp"
 	"strconv"
@@ -34,6 +35,7 @@ var (
 		IgnoreRedirect: false,
 		Timeout:        defaultTimeout,
 		Network:        "ip",
+		StoreCookies:   false,
 	}
 )
 
@@ -82,6 +84,9 @@ type Config struct {
 	// ResolvedTunnel is the resolved SSH tunnel for this specific Config
 	ResolvedTunnel *sshtunnel.SSHTunnel `yaml:"-"`
 
+	// StoreCookies determines whether cookies are stored and included across requests.
+	StoreCookies bool `yaml:"store-cookies,omitempty"`
+
 	httpClient *http.Client
 }
 
@@ -280,6 +285,13 @@ func (c *Config) getHTTPClient() *http.Client {
 				}
 			}
 		}
+		if c.StoreCookies {
+			jar, err := cookiejar.New(nil)
+			if err != nil {
+				logr.Fatalf("[client.getHTTPClient] Failed to initialize cookie jar: %v", err)
+			}
+			c.httpClient.Jar = jar
+		}
 	}
 	return c.httpClient
 }

client/config_test.go

@@ -17,6 +17,9 @@ func TestConfig_getHTTPClient(t *testing.T) {
 	if insecureClient.Timeout != defaultTimeout {
 		t.Error("expected Config.Timeout to default the HTTP client to a timeout of 10s")
 	}
+	if insecureClient.Jar != nil {
+		t.Error("expected Config.StoreCookies to default the HTTP client to not store cookies")
+	}
 	request, _ := http.NewRequest("GET", "", nil)
 	if err := insecureClient.CheckRedirect(request, nil); err != nil {
 		t.Error("expected Config.IgnoreRedirect set to false to cause the HTTP client's CheckRedirect to return nil")
@@ -31,12 +34,24 @@ func TestConfig_getHTTPClient(t *testing.T) {
 	if secureClient.Timeout != 5*time.Second {
 		t.Error("expected Config.Timeout to cause the HTTP client to have a timeout of 5s")
 	}
+	if insecureClient.Jar != nil {
+		t.Error("expected Config.StoreCookies to default the HTTP client to not store cookies")
+	}
 	request, _ = http.NewRequest("GET", "", nil)
 	if err := secureClient.CheckRedirect(request, nil); err != http.ErrUseLastResponse {
 		t.Error("expected Config.IgnoreRedirect set to true to cause the HTTP client's CheckRedirect to return http.ErrUseLastResponse")
 	}
 }
 
+func TestConfig_getHTTPClient_withCookieJar(t *testing.T) {
+	config := &Config{StoreCookies: true}
+	config.ValidateAndSetDefaults()
+	client := config.getHTTPClient()
+	if client.Jar == nil {
+		t.Error("expected Config.StoreCookies to cause the HTTP client to have a CookieJar")
+	}
+}
+
 func TestConfig_ValidateAndSetDefaults_withCustomDNSResolver(t *testing.T) {
 	type args struct {
 		dnsResolver string