fix cluster controller (#1996)

pkg/apiserver/dispatch/dispatch.go

@@ -6,6 +6,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/util/proxy"
 	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
+	"k8s.io/klog"
 	clusterv1alpha1 "kubesphere.io/kubesphere/pkg/apis/cluster/v1alpha1"
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 	"kubesphere.io/kubesphere/pkg/client/listers/cluster/v1alpha1"
@@ -13,27 +14,46 @@ import (
 	"strings"
 )
 
-const defaultMultipleClusterAgentNamespace = "kubesphere-system"
-
 // Dispatcher defines how to forward request to designated cluster based on cluster name
 type Dispatcher interface {
 	Dispatch(w http.ResponseWriter, req *http.Request, handler http.Handler)
 }
 
 type clusterDispatch struct {
-	agentLister v1alpha1.AgentLister
+	agentLister   v1alpha1.AgentLister
+	clusterLister v1alpha1.ClusterLister
 }
 
-func NewClusterDispatch(agentLister v1alpha1.AgentLister) Dispatcher {
+func NewClusterDispatch(agentLister v1alpha1.AgentLister, clusterLister v1alpha1.ClusterLister) Dispatcher {
 	return &clusterDispatch{
-		agentLister: agentLister,
+		agentLister:   agentLister,
+		clusterLister: clusterLister,
 	}
 }
 
 func (c *clusterDispatch) Dispatch(w http.ResponseWriter, req *http.Request, handler http.Handler) {
 
 	info, _ := request.RequestInfoFrom(req.Context())
-	if info.Cluster == "" { // fallback to host cluster if cluster name if empty
+
+	if len(info.Cluster) == 0 {
+		klog.Warningf("Request with empty cluster, %v", req.URL)
+		http.Error(w, fmt.Sprintf("Bad request, empty cluster"), http.StatusBadRequest)
+		return
+	}
+
+	cluster, err := c.clusterLister.Get(info.Cluster)
+	if err != nil {
+		if errors.IsNotFound(err) {
+			http.Error(w, fmt.Sprintf("cluster %s not found", info.Cluster), http.StatusNotFound)
+		} else {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+		return
+	}
+
+	// request cluster is host cluster, no need go through agent
+	if isClusterHostCluster(cluster) {
+		req.URL.Path = strings.Replace(req.URL.Path, fmt.Sprintf("/clusters/%s", info.Cluster), "", 1)
 		handler.ServeHTTP(w, req)
 		return
 	}
@@ -74,3 +94,14 @@ func isAgentReady(agent *clusterv1alpha1.Agent) bool {
 
 	return false
 }
+
+//
+func isClusterHostCluster(cluster *clusterv1alpha1.Cluster) bool {
+	for key, value := range cluster.Annotations {
+		if key == clusterv1alpha1.IsHostCluster && value == "true" {
+			return true
+		}
+	}
+
+	return false
+}