Add api to get cluster nodes' resources (#260)

restapi/admin_nodes.go

@@ -0,0 +1,119 @@
+// This file is part of MinIO Console Server
+// Copyright (c) 2020 MinIO, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package restapi
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/minio/console/cluster"
+
+	"github.com/go-openapi/runtime/middleware"
+	"github.com/go-openapi/swag"
+	"github.com/minio/console/models"
+	"github.com/minio/console/restapi/operations"
+	"github.com/minio/console/restapi/operations/admin_api"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
+)
+
+func registerNodesHandlers(api *operations.ConsoleAPI) {
+	api.AdminAPIGetClusterResourcesHandler = admin_api.GetClusterResourcesHandlerFunc(func(params admin_api.GetClusterResourcesParams, session *models.Principal) middleware.Responder {
+		resp, err := getClusterResourcesResponse(session)
+		if err != nil {
+			return admin_api.NewGetClusterResourcesDefault(500).WithPayload(&models.Error{Code: 500, Message: swag.String(err.Error())})
+		}
+		return admin_api.NewGetClusterResourcesOK().WithPayload(resp)
+	})
+}
+
+// getClusterResources get cluster nodes and collects taints, available and allocatable resources of the node
+func getClusterResources(ctx context.Context, clientset v1.CoreV1Interface) (*models.ClusterResources, error) {
+	// get all nodes from cluster
+	nodes, err := clientset.Nodes().List(ctx, metav1.ListOptions{})
+	if err != nil {
+		return nil, err
+	}
+	// construct ClusterResources response
+	res := &models.ClusterResources{}
+
+	for _, n := range nodes.Items {
+		// Get Total Resources
+		totalResources := make(map[string]int64)
+		for resource, quantity := range n.Status.Capacity {
+			totalResources[string(resource)] = quantity.Value()
+		}
+
+		// Get Allocatable Resources
+		allocatableResources := make(map[string]int64)
+		for resource, quantity := range n.Status.Allocatable {
+			allocatableResources[string(resource)] = quantity.Value()
+		}
+
+		// Get Node taints and split them by effect
+		taints := &models.NodeTaints{}
+		for _, t := range n.Spec.Taints {
+			var taint string
+			// when value is not defined the taint string is created without `=`
+			if strings.TrimSpace(t.Value) != "" {
+				taint = fmt.Sprintf("%s=%s:%s", t.Key, t.Value, t.Effect)
+			} else {
+				taint = fmt.Sprintf("%s:%s", t.Key, t.Effect)
+			}
+			switch t.Effect {
+			case corev1.TaintEffectNoSchedule:
+				taints.NoSchedule = append(taints.NoSchedule, taint)
+			case corev1.TaintEffectNoExecute:
+				taints.NoExecute = append(taints.NoExecute, taint)
+			case corev1.TaintEffectPreferNoSchedule:
+				taints.PreferNoSchedule = append(taints.PreferNoSchedule, taint)
+			default:
+				continue
+			}
+		}
+
+		// create node object an add it to the nodes list
+		nodeInfo := &models.NodeInfo{
+			Name:                 n.Name,
+			Taints:               taints,
+			AllocatableResources: allocatableResources,
+			TotalResources:       totalResources,
+		}
+		res.Nodes = append(res.Nodes, nodeInfo)
+	}
+	return res, nil
+}
+
+func getClusterResourcesResponse(session *models.Principal) (*models.ClusterResources, error) {
+	ctx := context.Background()
+	client, err := cluster.K8sClient(session.SessionToken)
+	if err != nil {
+		log.Println("error getting k8sClient:", err)
+		return nil, err
+	}
+
+	clusterResources, err := getClusterResources(ctx, client.CoreV1())
+	if err != nil {
+		log.Println("error getting cluster's resources:", err)
+		return nil, err
+
+	}
+	return clusterResources, nil
+}