support run work agent outside of managed cluster

Makefile

@@ -40,16 +40,18 @@ clean:
 
 cluster-ip:
 	$(KUBECTL) config use-context $(HUB_KUBECONFIG_CONTEXT) --kubeconfig $(HUB_KUBECONFIG)
-  	CLUSTER_IP?=$(shell $(KUBECTL) --kubeconfig $(HUB_KUBECONFIG) get svc kubernetes -n default -o jsonpath="{.spec.clusterIP}")
+	$(eval CLUSTER_IP?=$(shell $(KUBECTL) --kubeconfig $(HUB_KUBECONFIG) get svc kubernetes -n default -o jsonpath="{.spec.clusterIP}"))
 
 hub-kubeconfig-secret: cluster-ip
 	$(KUBECTL) config use-context $(SPOKE_KUBECONFIG_CONTEXT) --kubeconfig $(SPOKE_KUBECONFIG)
 	$(KUBECTL) apply -f deploy/spoke/component_namespace.yaml --kubeconfig $(SPOKE_KUBECONFIG)
 	$(KUBECTL) delete secret hub-kubeconfig-secret -n open-cluster-management-agent --ignore-not-found --kubeconfig $(SPOKE_KUBECONFIG)
 	$(KUBECTL) config use-context $(HUB_KUBECONFIG_CONTEXT) --kubeconfig $(HUB_KUBECONFIG)
 	$(KUBECTL) config view --flatten --minify --kubeconfig $(HUB_KUBECONFIG) > hub-kubeconfig
-ifeq ($(HUB_KUBECONFIG), $(SPOKE_KUBECONFIG)) && ($(HUB_KUBECONFIG_CONTEXT), $(SPOKE_KUBECONFIG_CONTEXT))
+ifeq ($(HUB_KUBECONFIG), $(SPOKE_KUBECONFIG))
+ifeq ($(HUB_KUBECONFIG_CONTEXT), $(SPOKE_KUBECONFIG_CONTEXT))
 	$(KUBECTL) config set clusters.$(HUB_KUBECONFIG_CONTEXT).server https://$(CLUSTER_IP) --kubeconfig hub-kubeconfig
+endif
 endif
 	$(KUBECTL) config use-context $(SPOKE_KUBECONFIG_CONTEXT) --kubeconfig $(SPOKE_KUBECONFIG)
 	$(KUBECTL) create secret generic hub-kubeconfig-secret --from-file=kubeconfig=hub-kubeconfig -n open-cluster-management-agent --kubeconfig $(SPOKE_KUBECONFIG)

deploy/webhook/kustomization.yaml

@@ -1,6 +1,6 @@
 
 # Adds namespace to all resources.
-namespace: open-cluster-management
+namespace: open-cluster-management-hub
 
 # Value of this field is prepended to the
 # names of all resources, e.g. a deployment named

pkg/spoke/spokeagent.go

@@ -2,6 +2,7 @@ package spoke
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"open-cluster-management.io/work/pkg/helper"
@@ -16,6 +17,7 @@ import (
 	apiextensionsclient "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 
 	workclientset "open-cluster-management.io/api/client/work/clientset/versioned"
@@ -24,10 +26,11 @@ import (
 
 // WorkloadAgentOptions defines the flags for workload agent
 type WorkloadAgentOptions struct {
-	HubKubeconfigFile string
-	SpokeClusterName  string
-	QPS               float32
-	Burst             int
+	HubKubeconfigFile   string
+	SpokeKubeconfigFile string
+	SpokeClusterName    string
+	QPS                 float32
+	Burst               int
 }
 
 // NewWorkloadAgentOptions returns the flags with default value set
@@ -43,6 +46,8 @@ func (o *WorkloadAgentOptions) AddFlags(cmd *cobra.Command) {
 	flags := cmd.Flags()
 	// This command only supports reading from config
 	flags.StringVar(&o.HubKubeconfigFile, "hub-kubeconfig", o.HubKubeconfigFile, "Location of kubeconfig file to connect to hub cluster.")
+	flags.StringVar(&o.SpokeKubeconfigFile, "spoke-kubeconfig", o.SpokeKubeconfigFile,
+		"Location of kubeconfig file to connect to spoke cluster. If this is not set, will use '--kubeconfig' to build client to connect to the managed cluster.")
 	flags.StringVar(&o.SpokeClusterName, "spoke-cluster-name", o.SpokeClusterName, "Name of spoke cluster.")
 	flags.Float32Var(&o.QPS, "spoke-kube-api-qps", o.QPS, "QPS to use while talking with apiserver on spoke cluster.")
 	flags.IntVar(&o.Burst, "spoke-kube-api-burst", o.Burst, "Burst to use while talking with apiserver on spoke cluster.")
@@ -64,8 +69,13 @@ func (o *WorkloadAgentOptions) RunWorkloadAgent(ctx context.Context, controllerC
 	// Only watch the cluster namespace on hub
 	workInformerFactory := workinformers.NewSharedInformerFactoryWithOptions(hubWorkClient, 5*time.Minute, workinformers.WithNamespace(o.SpokeClusterName))
 
-	// Build dynamic client and informer for spoke cluster
-	spokeRestConfig := controllerContext.KubeConfig
+	// load spoke client config and create spoke clients,
+	// the work agent may not running in the spoke/managed cluster.
+	spokeRestConfig, err := o.spokeKubeConfig(controllerContext)
+	if err != nil {
+		return err
+	}
+
 	spokeRestConfig.QPS = o.QPS
 	spokeRestConfig.Burst = o.Burst
 	spokeDynamicClient, err := dynamic.NewForConfig(spokeRestConfig)
@@ -154,3 +164,16 @@ func (o *WorkloadAgentOptions) RunWorkloadAgent(ctx context.Context, controllerC
 	<-ctx.Done()
 	return nil
 }
+
+// spokeKubeConfig builds kubeconfig for the spoke/managed cluster
+func (o *WorkloadAgentOptions) spokeKubeConfig(controllerContext *controllercmd.ControllerContext) (*rest.Config, error) {
+	if o.SpokeKubeconfigFile == "" {
+		return controllerContext.KubeConfig, nil
+	}
+
+	spokeRestConfig, err := clientcmd.BuildConfigFromFlags("" /* leave masterurl as empty */, o.SpokeKubeconfigFile)
+	if err != nil {
+		return nil, fmt.Errorf("unable to load spoke kubeconfig from file %q: %w", o.SpokeKubeconfigFile, err)
+	}
+	return spokeRestConfig, nil
+}