feat: expose a more basic member clusters discovery interface (#94)

* feat: expose a more basic member clusters discovery interface

* fix lint

Author: zoumo

multicluster/manager.go

@@ -27,8 +27,7 @@ import (
 	"github.com/go-logr/logr"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/client-go/discovery/cached/memory"
-	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/klog/v2/klogr"
@@ -162,11 +161,10 @@ func (m *Manager) addUpdateHandler(cluster string, cfg *rest.Config) (err error)
 	m.mutex.RUnlock()
 
 	// Get MemCacheClient for the cluster
-	clientset, err := kubernetes.NewForConfig(cfg)
+	discoveryClient, err := discovery.NewDiscoveryClientForConfig(cfg)
 	if err != nil {
 		return err
 	}
-	clusterCachedDiscoveryClient := memory.NewMemCacheClient(clientset.Discovery())
 
 	// Create cache for the cluster
 	mapper, err := apiutil.NewDynamicRESTMapper(cfg)
@@ -202,7 +200,7 @@ func (m *Manager) addUpdateHandler(cluster string, cfg *rest.Config) (err error)
 
 	m.log.Info("add cluster", "cluster", cluster)
 	m.clusterCacheManager.AddClusterCache(cluster, clusterCache)
-	m.clusterClientManager.AddClusterClient(cluster, delegatingClusterClient, clusterCachedDiscoveryClient)
+	m.clusterClientManager.AddClusterClient(cluster, delegatingClusterClient, discoveryClient)
 
 	m.mutex.Lock()
 	m.hasCluster[cluster] = struct{}{}

multicluster/manager_test.go

@@ -184,10 +184,10 @@ var _ = Describe("multicluster", func() {
 	})
 
 	It("multiClusterClient get server groups and resources", func() {
-		mcdiscovery, ok := clusterClient.(MultiClusterDiscovery)
+		mcdiscovery, ok := clusterClient.(MultiClusterDiscoveryManager)
 		Expect(ok).To(BeTrue())
-		cachedDiscoveryClient := mcdiscovery.MembersCachedDiscoveryInterface()
-		apiGroups, apiResourceLists, err := cachedDiscoveryClient.ServerGroupsAndResources()
+		_, allDiscoveryClients := mcdiscovery.GetAllDiscoveryInterface()
+		apiGroups, apiResourceLists, err := GetAllClusterServerGroupsAndResources(allDiscoveryClients)
 		Expect(err).NotTo(HaveOccurred())
 
 		groupVersionSets := sets.NewString()

multicluster/multi_cluster_client.go

@@ -24,7 +24,6 @@ import (
 
 	"github.com/go-logr/logr"
 	"k8s.io/apimachinery/pkg/api/meta"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/discovery"
@@ -37,28 +36,15 @@ import (
 	"kusionstack.io/kube-utils/multicluster/metrics"
 )
 
-// MultiClusterDiscovery provides fed and member clusters discovery interface
-type MultiClusterDiscovery interface {
-	FedDiscoveryInterface() discovery.DiscoveryInterface
-	MembersCachedDiscoveryInterface() PartialCachedDiscoveryInterface
-}
-
-// PartialCachedDiscoveryInterface is a subset of discovery.DiscoveryInterface.
-type PartialCachedDiscoveryInterface interface {
-	ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error)
-	Invalidate()
-	Fresh() bool
-}
-
 type ClusterClientManager interface {
-	AddClusterClient(cluster string, clusterClient client.Client, clusterCachedDiscoveryClient discovery.CachedDiscoveryInterface)
+	AddClusterClient(cluster string, clusterClient client.Client, discoveryClient discovery.DiscoveryInterface)
 	RemoveClusterClient(cluster string)
 }
 
 func MultiClusterClientBuilder(log logr.Logger) (cluster.NewClientFunc, ClusterClientManager) {
 	mcc := &multiClusterClient{
 		clusterToClient:          map[string]client.Client{},
-		clusterToDiscoveryClient: map[string]discovery.CachedDiscoveryInterface{},
+		clusterToDiscoveryClient: map[string]discovery.DiscoveryInterface{},
 
 		log: log,
 	}
@@ -97,7 +83,7 @@ func MultiClusterClientBuilder(log logr.Logger) (cluster.NewClientFunc, ClusterC
 var (
 	_ client.Client = &multiClusterClient{}
 
-	_ MultiClusterDiscovery = &multiClusterClient{}
+	_ MultiClusterDiscoveryManager = &multiClusterClient{}
 
 	_ ClusterClientManager = &multiClusterClient{}
 )
@@ -109,13 +95,13 @@ type multiClusterClient struct {
 	fedMapper    meta.RESTMapper
 
 	clusterToClient          map[string]client.Client
-	clusterToDiscoveryClient map[string]discovery.CachedDiscoveryInterface
+	clusterToDiscoveryClient map[string]discovery.DiscoveryInterface
 
 	mutex sync.RWMutex
 	log   logr.Logger
 }
 
-func (mcc *multiClusterClient) AddClusterClient(cluster string, clusterClient client.Client, clusterDiscoveryClient discovery.CachedDiscoveryInterface) {
+func (mcc *multiClusterClient) AddClusterClient(cluster string, clusterClient client.Client, clusterDiscoveryClient discovery.DiscoveryInterface) {
 	mcc.mutex.Lock()
 	defer mcc.mutex.Unlock()
 
@@ -478,113 +464,3 @@ func (mcc *multiClusterClient) getClusterNames(ctx context.Context) (clusters []
 	}
 	return
 }
-
-func (mcc *multiClusterClient) FedDiscoveryInterface() discovery.DiscoveryInterface {
-	return mcc.fedDiscovery
-}
-
-func (mcc *multiClusterClient) MembersCachedDiscoveryInterface() PartialCachedDiscoveryInterface {
-	return &cachedMultiClusterDiscoveryClient{
-		delegate: mcc,
-	}
-}
-
-type cachedMultiClusterDiscoveryClient struct {
-	delegate *multiClusterClient
-}
-
-// ServerGroupsAndResources returns the supported server groups and resources for all clusters.
-func (c *cachedMultiClusterDiscoveryClient) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
-	c.delegate.mutex.Lock()
-	defer c.delegate.mutex.Unlock()
-
-	allDiscoveryClient := c.delegate.clusterToDiscoveryClient
-
-	// If there is only one cluster, we can use the cached discovery client to get the server groups and resources
-	if len(allDiscoveryClient) == 1 {
-		for _, cachedClient := range allDiscoveryClient {
-			return cachedClient.ServerGroupsAndResources()
-		}
-	}
-
-	// If there are multiple clusters, we need to get the intersection of groups and resources
-	var (
-		groupVersionCount     = make(map[string]int)
-		groupVersionNameCount = make(map[string]int)
-
-		apiGroupsRes            []*metav1.APIGroup
-		apiResourceListsRes     []*metav1.APIResourceList
-		groupVersionToResources = make(map[string][]metav1.APIResource)
-	)
-	for _, cachedClient := range allDiscoveryClient {
-		apiGroups, apiResourceLists, err := cachedClient.ServerGroupsAndResources()
-		if err != nil {
-			return nil, nil, err
-		}
-
-		for _, apiGroup := range apiGroups {
-			groupVersion := apiGroup.PreferredVersion.GroupVersion
-
-			if _, ok := groupVersionCount[groupVersion]; !ok {
-				groupVersionCount[groupVersion] = 1
-			} else {
-				groupVersionCount[groupVersion]++
-
-				if groupVersionCount[groupVersion] == len(allDiscoveryClient) { // all clusters have this PreferredVersion
-					apiGroupsRes = append(apiGroupsRes, apiGroup)
-				}
-			}
-		}
-
-		for _, apiResourceList := range apiResourceLists {
-			for i := range apiResourceList.APIResources {
-				apiResource := apiResourceList.APIResources[i]
-				groupVersionName := fmt.Sprintf("%s/%s", apiResourceList.GroupVersion, apiResource.Name)
-
-				if _, ok := groupVersionNameCount[groupVersionName]; !ok {
-					groupVersionNameCount[groupVersionName] = 1
-				} else {
-					groupVersionNameCount[groupVersionName]++
-
-					if groupVersionNameCount[groupVersionName] == len(allDiscoveryClient) { // all clusters have this GroupVersion and Name
-						groupVersionToResources[apiResourceList.GroupVersion] = append(groupVersionToResources[apiResourceList.GroupVersion], apiResource)
-					}
-				}
-			}
-		}
-	}
-
-	for groupVersion, resources := range groupVersionToResources {
-		apiResourceList := metav1.APIResourceList{
-			TypeMeta:     metav1.TypeMeta{Kind: "APIResourceList", APIVersion: "v1"},
-			GroupVersion: groupVersion,
-		}
-		apiResourceList.APIResources = append(apiResourceList.APIResources, resources...)
-		apiResourceListsRes = append(apiResourceListsRes, &apiResourceList)
-	}
-
-	return apiGroupsRes, apiResourceListsRes, nil
-}
-
-// Invalidate invalidates the cached discovery clients for all clusters.
-func (c *cachedMultiClusterDiscoveryClient) Invalidate() {
-	c.delegate.mutex.Lock()
-	defer c.delegate.mutex.Unlock()
-
-	for _, cachedClient := range c.delegate.clusterToDiscoveryClient {
-		cachedClient.Invalidate()
-	}
-}
-
-// Fresh returns true if all cached discovery clients are fresh.
-func (c *cachedMultiClusterDiscoveryClient) Fresh() bool {
-	c.delegate.mutex.Lock()
-	defer c.delegate.mutex.Unlock()
-
-	for _, cachedClient := range c.delegate.clusterToDiscoveryClient {
-		if !cachedClient.Fresh() {
-			return false
-		}
-	}
-	return true
-}

multicluster/multi_cluster_discovery.go

@@ -0,0 +1,110 @@
+/**
+ * Copyright 2025 KusionStack Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package multicluster
+
+import (
+	"fmt"
+	"maps"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/discovery"
+)
+
+// MultiClusterDiscovery provides fed and member clusters discovery interface
+type MultiClusterDiscoveryManager interface {
+	// GetAllDiscoveryInterface returns the fed and member clusters discovery interface
+	GetAllDiscoveryInterface() (fed discovery.DiscoveryInterface, members map[string]discovery.DiscoveryInterface)
+}
+
+func (mcc *multiClusterClient) GetAllDiscoveryInterface() (discovery.DiscoveryInterface, map[string]discovery.DiscoveryInterface) {
+	mcc.mutex.RLock()
+	defer mcc.mutex.RUnlock()
+	members := make(map[string]discovery.DiscoveryInterface)
+	maps.Copy(members, mcc.clusterToDiscoveryClient)
+	return mcc.fedDiscovery, members
+}
+
+func GetAllClusterServerGroupsAndResources(membersDiscoveryClients map[string]discovery.DiscoveryInterface) ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
+	totalClusters := len(membersDiscoveryClients)
+	if totalClusters == 0 {
+		return nil, nil, nil
+	}
+	// If there is only one cluster, we can use the cached discovery client to get the server groups and resources
+	if totalClusters == 1 {
+		for _, cachedClient := range membersDiscoveryClients {
+			return cachedClient.ServerGroupsAndResources()
+		}
+	}
+
+	// If there are multiple clusters, we need to get the intersection of groups and resources
+	var (
+		groupVersionCount     = make(map[string]int)
+		groupVersionNameCount = make(map[string]int)
+
+		apiGroupsRes            []*metav1.APIGroup
+		apiResourceListsRes     []*metav1.APIResourceList
+		groupVersionToResources = make(map[string][]metav1.APIResource)
+	)
+	for _, discoveryClient := range membersDiscoveryClients {
+		apiGroups, apiResourceLists, err := discoveryClient.ServerGroupsAndResources()
+		if err != nil {
+			return nil, nil, err
+		}
+
+		for _, apiGroup := range apiGroups {
+			groupVersion := apiGroup.PreferredVersion.GroupVersion
+
+			if _, ok := groupVersionCount[groupVersion]; !ok {
+				groupVersionCount[groupVersion] = 1
+			} else {
+				groupVersionCount[groupVersion]++
+
+				if groupVersionCount[groupVersion] == totalClusters { // all clusters have this PreferredVersion
+					apiGroupsRes = append(apiGroupsRes, apiGroup)
+				}
+			}
+		}
+
+		for _, apiResourceList := range apiResourceLists {
+			for i := range apiResourceList.APIResources {
+				apiResource := apiResourceList.APIResources[i]
+				groupVersionName := fmt.Sprintf("%s/%s", apiResourceList.GroupVersion, apiResource.Name)
+
+				if _, ok := groupVersionNameCount[groupVersionName]; !ok {
+					groupVersionNameCount[groupVersionName] = 1
+				} else {
+					groupVersionNameCount[groupVersionName]++
+
+					if groupVersionNameCount[groupVersionName] == totalClusters { // all clusters have this GroupVersion and Name
+						groupVersionToResources[apiResourceList.GroupVersion] = append(groupVersionToResources[apiResourceList.GroupVersion], apiResource)
+					}
+				}
+			}
+		}
+	}
+
+	for groupVersion, resources := range groupVersionToResources {
+		apiResourceList := metav1.APIResourceList{
+			TypeMeta:     metav1.TypeMeta{Kind: "APIResourceList", APIVersion: "v1"},
+			GroupVersion: groupVersion,
+		}
+		apiResourceList.APIResources = append(apiResourceList.APIResources, resources...)
+		apiResourceListsRes = append(apiResourceListsRes, &apiResourceList)
+	}
+
+	return apiGroupsRes, apiResourceListsRes, nil
+}