use ClusterIPServiceResolver instead of DefaultServiceResolver to eli…

…minate dependency of DNS

Signed-off-by: lxtywypc <lxtywypc@gmail.com>

cmd/agent/app/agent.go

@@ -11,6 +11,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/informers"
 	kubeclientset "k8s.io/client-go/kubernetes"
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/term"
@@ -229,7 +230,16 @@ func setupControllers(mgr controllerruntime.Manager, opts *options.Options, stop
 	restConfig := mgr.GetConfig()
 	dynamicClientSet := dynamic.NewForConfigOrDie(restConfig)
 	controlPlaneInformerManager := genericmanager.NewSingleClusterInformerManager(dynamicClientSet, 0, stopChan)
-	resourceInterpreter := resourceinterpreter.NewResourceInterpreter(controlPlaneInformerManager)
+	controlPlaneKubeClientSet := kubeclientset.NewForConfigOrDie(restConfig)
+
+	// We need a service lister to build a resource interpreter with `ClusterIPServiceResolver`
+	// witch allows connection to the customized interpreter webhook without a cluster DNS service.
+	sharedFactory := informers.NewSharedInformerFactory(controlPlaneKubeClientSet, 0)
+	serviceLister := sharedFactory.Core().V1().Services().Lister()
+	sharedFactory.Start(stopChan)
+	sharedFactory.WaitForCacheSync(stopChan)
+
+	resourceInterpreter := resourceinterpreter.NewResourceInterpreter(controlPlaneInformerManager, serviceLister)
 	if err := mgr.Add(resourceInterpreter); err != nil {
 		return fmt.Errorf("failed to setup custom resource interpreter: %w", err)
 	}

cmd/controller-manager/app/controllermanager.go

@@ -12,6 +12,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/informers"
 	kubeclientset "k8s.io/client-go/kubernetes"
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/term"
@@ -535,6 +536,7 @@ func setupControllers(mgr controllerruntime.Manager, opts *options.Options, stop
 	restConfig := mgr.GetConfig()
 	dynamicClientSet := dynamic.NewForConfigOrDie(restConfig)
 	discoverClientSet := discovery.NewDiscoveryClientForConfigOrDie(restConfig)
+	kubeClientSet := kubeclientset.NewForConfigOrDie(restConfig)
 
 	overrideManager := overridemanager.New(mgr.GetClient(), mgr.GetEventRecorderFor(overridemanager.OverrideManagerName))
 	skippedResourceConfig := util.NewSkippedResourceConfig()
@@ -550,7 +552,14 @@ func setupControllers(mgr controllerruntime.Manager, opts *options.Options, stop
 
 	controlPlaneInformerManager := genericmanager.NewSingleClusterInformerManager(dynamicClientSet, 0, stopChan)
 
-	resourceInterpreter := resourceinterpreter.NewResourceInterpreter(controlPlaneInformerManager)
+	// We need a service lister to build a resource interpreter with `ClusterIPServiceResolver`
+	// witch allows connection to the customized interpreter webhook without a cluster DNS service.
+	sharedFactory := informers.NewSharedInformerFactory(kubeClientSet, 0)
+	serviceLister := sharedFactory.Core().V1().Services().Lister()
+	sharedFactory.Start(stopChan)
+	sharedFactory.WaitForCacheSync(stopChan)
+
+	resourceInterpreter := resourceinterpreter.NewResourceInterpreter(controlPlaneInformerManager, serviceLister)
 	if err := mgr.Add(resourceInterpreter); err != nil {
 		klog.Fatalf("Failed to setup custom resource interpreter: %v", err)
 	}

pkg/resourceinterpreter/customized/webhook/customized.go

@@ -13,7 +13,9 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	webhookutil "k8s.io/apiserver/pkg/util/webhook"
+	corev1 "k8s.io/client-go/listers/core/v1"
 	"k8s.io/klog/v2"
+	"k8s.io/kube-aggregator/pkg/apiserver"
 	utiltrace "k8s.io/utils/trace"
 
 	configv1alpha1 "github.com/karmada-io/karmada/pkg/apis/config/v1alpha1"
@@ -33,7 +35,7 @@ type CustomizedInterpreter struct {
 }
 
 // NewCustomizedInterpreter return a new CustomizedInterpreter.
-func NewCustomizedInterpreter(informer genericmanager.SingleClusterInformerManager) (*CustomizedInterpreter, error) {
+func NewCustomizedInterpreter(informer genericmanager.SingleClusterInformerManager, serviceLister corev1.ServiceLister) (*CustomizedInterpreter, error) {
 	cm, err := webhookutil.NewClientManager(
 		[]schema.GroupVersion{configv1alpha1.SchemeGroupVersion},
 		configv1alpha1.AddToScheme,
@@ -45,8 +47,9 @@ func NewCustomizedInterpreter(informer genericmanager.SingleClusterInformerManag
 	if err != nil {
 		return nil, err
 	}
+
 	cm.SetAuthenticationInfoResolver(authInfoResolver)
-	cm.SetServiceResolver(webhookutil.NewDefaultServiceResolver())
+	cm.SetServiceResolver(apiserver.NewClusterIPServiceResolver(serviceLister))
 
 	return &CustomizedInterpreter{
 		hookManager:   configmanager.NewExploreConfigManager(informer),

pkg/resourceinterpreter/interpreter.go

@@ -6,6 +6,7 @@ import (
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	corev1 "k8s.io/client-go/listers/core/v1"
 	"k8s.io/klog/v2"
 
 	configv1alpha1 "github.com/karmada-io/karmada/pkg/apis/config/v1alpha1"
@@ -51,14 +52,16 @@ type ResourceInterpreter interface {
 }
 
 // NewResourceInterpreter builds a new ResourceInterpreter object.
-func NewResourceInterpreter(informer genericmanager.SingleClusterInformerManager) ResourceInterpreter {
+func NewResourceInterpreter(informer genericmanager.SingleClusterInformerManager, serviceLister corev1.ServiceLister) ResourceInterpreter {
 	return &customResourceInterpreterImpl{
-		informer: informer,
+		informer:      informer,
+		serviceLister: serviceLister,
 	}
 }
 
 type customResourceInterpreterImpl struct {
-	informer genericmanager.SingleClusterInformerManager
+	informer      genericmanager.SingleClusterInformerManager
+	serviceLister corev1.ServiceLister
 
 	configurableInterpreter *declarative.ConfigurableInterpreter
 	customizedInterpreter   *webhook.CustomizedInterpreter
@@ -70,7 +73,7 @@ type customResourceInterpreterImpl struct {
 func (i *customResourceInterpreterImpl) Start(ctx context.Context) (err error) {
 	klog.Infof("Starting custom resource interpreter.")
 
-	i.customizedInterpreter, err = webhook.NewCustomizedInterpreter(i.informer)
+	i.customizedInterpreter, err = webhook.NewCustomizedInterpreter(i.informer, i.serviceLister)
 	if err != nil {
 		return
 	}