Fix dynamic resource API (#5573)

pkg/apiserver/apiserver.go

@@ -33,7 +33,6 @@ import (
 	urlruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	unionauth "k8s.io/apiserver/pkg/authentication/request/union"
-	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/util/retry"
 	"k8s.io/klog/v2"
@@ -61,9 +60,7 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/authorization/rbac"
 	unionauthorizer "kubesphere.io/kubesphere/pkg/apiserver/authorization/union"
 	apiserverconfig "kubesphere.io/kubesphere/pkg/apiserver/config"
-	"kubesphere.io/kubesphere/pkg/apiserver/dispatch"
 	"kubesphere.io/kubesphere/pkg/apiserver/filters"
-	"kubesphere.io/kubesphere/pkg/apiserver/proxies"
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 	"kubesphere.io/kubesphere/pkg/informers"
 	alertingv1 "kubesphere.io/kubesphere/pkg/kapis/alerting/v1"
@@ -176,22 +173,21 @@ type APIServer struct {
 func (s *APIServer) PrepareRun(stopCh <-chan struct{}) error {
 	s.container = restful.NewContainer()
 	s.container.Filter(logRequestAndResponse)
+	s.container.Filter(monitorRequest)
 	s.container.Router(restful.CurlyRouter{})
 	s.container.RecoverHandler(func(panicReason interface{}, httpWriter http.ResponseWriter) {
 		logStackOnRecover(panicReason, httpWriter)
 	})
-
+	s.installDynamicResourceAPI()
 	s.installKubeSphereAPIs(stopCh)
 	s.installMetricsAPI()
 	s.installHealthz()
-	s.container.Filter(monitorRequest)
 
 	for _, ws := range s.container.RegisteredWebServices() {
 		klog.V(2).Infof("%s", ws.RootPath())
 	}
 
 	s.Server.Handler = s.container
-
 	s.buildHandlerChain(stopCh)
 
 	return nil
@@ -338,11 +334,9 @@ func (s *APIServer) buildHandlerChain(stopCh <-chan struct{}) {
 			notificationv2beta2.Resource(notificationv2beta2.ResourcesPluralSilence),
 		)
 	}
-	handler := s.Server.Handler
-	handler = filters.WithKubeAPIServer(handler, s.KubernetesClient.Config(), &errorResponder{})
 
-	middleware := proxies.NewUnregisteredMiddleware(s.container, resourcev1beta1.New(s.RuntimeClient, s.RuntimeCache))
-	handler = filters.WithMiddleware(handler, middleware)
+	handler := s.Server.Handler
+	handler = filters.WithKubeAPIServer(handler, s.KubernetesClient.Config())
 
 	if s.Config.AuditingOptions.Enable {
 		handler = filters.WithAuditing(handler,
@@ -367,8 +361,7 @@ func (s *APIServer) buildHandlerChain(stopCh <-chan struct{}) {
 
 	handler = filters.WithAuthorization(handler, authorizers)
 	if s.Config.MultiClusterOptions.Enable {
-		clusterDispatcher := dispatch.NewClusterDispatch(s.ClusterClient)
-		handler = filters.WithMultipleClusterDispatcher(handler, clusterDispatcher)
+		handler = filters.WithMulticluster(handler, s.ClusterClient)
 	}
 
 	userLister := s.InformerFactory.KubeSphereSharedInformerFactory().Iam().V1alpha2().Users().Lister()
@@ -633,6 +626,18 @@ func (s *APIServer) waitForResourceSync(ctx context.Context) error {
 
 }
 
+func (s *APIServer) installDynamicResourceAPI() {
+	dynamicResourceHandler := filters.NewDynamicResourceHandle(func(err restful.ServiceError, req *restful.Request, resp *restful.Response) {
+		for header, values := range err.Header {
+			for _, value := range values {
+				resp.Header().Add(header, value)
+			}
+		}
+		resp.WriteErrorString(err.Code, err.Message)
+	}, resourcev1beta1.New(s.RuntimeClient, s.RuntimeCache))
+	s.container.ServiceErrorHandler(dynamicResourceHandler.HandleServiceError)
+}
+
 func logStackOnRecover(panicReason interface{}, w http.ResponseWriter) {
 	var buffer bytes.Buffer
 	buffer.WriteString(fmt.Sprintf("recover from panic situation: - %v\r\n", panicReason))
@@ -674,10 +679,3 @@ func logRequestAndResponse(req *restful.Request, resp *restful.Response, chain *
 		time.Since(start)/time.Millisecond,
 	)
 }
-
-type errorResponder struct{}
-
-func (e *errorResponder) Error(w http.ResponseWriter, req *http.Request, err error) {
-	klog.Error(err)
-	responsewriters.InternalError(w, req, err)
-}

pkg/apiserver/dispatch/dispatch_test.go

@@ -1,17 +0,0 @@
-/*
-Copyright 2020 KubeSphere 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 dispatch

pkg/apiserver/filters/auditing.go

@@ -25,39 +25,45 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 )
 
-func WithAuditing(handler http.Handler, a auditing.Auditing) http.Handler {
-
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-
-		// When auditing level is LevelNone, request should not be auditing.
-		// Auditing level can be modified with cr kube-auditing-webhook,
-		// so it need to judge every time.
-		if !a.Enabled() {
-			handler.ServeHTTP(w, req)
-			return
-		}
-
-		info, ok := request.RequestInfoFrom(req.Context())
-		if !ok {
-			klog.Error("Unable to retrieve request info from request")
-			handler.ServeHTTP(w, req)
-			return
-		}
-
-		// Auditing should igonre k8s request when k8s auditing is enabled.
-		if info.IsKubernetesRequest && a.K8sAuditingEnabled() {
-			handler.ServeHTTP(w, req)
-			return
-		}
-
-		e := a.LogRequestObject(req, info)
-		if e != nil {
-			resp := auditing.NewResponseCapture(w)
-			handler.ServeHTTP(resp, req)
-
-			go a.LogResponseObject(e, resp)
-		} else {
-			handler.ServeHTTP(w, req)
-		}
-	})
+type auditingFilter struct {
+	next http.Handler
+	auditing.Auditing
+}
+
+func WithAuditing(next http.Handler, auditing auditing.Auditing) http.Handler {
+	return &auditingFilter{
+		next:     next,
+		Auditing: auditing,
+	}
+}
+
+func (a *auditingFilter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	// When auditing level is LevelNone, request should not be auditing.
+	// Auditing level can be modified with cr kube-auditing-webhook,
+	// so it need to judge every time.
+	if !a.Enabled() {
+		a.next.ServeHTTP(w, req)
+		return
+	}
+
+	info, ok := request.RequestInfoFrom(req.Context())
+	if !ok {
+		klog.Error("Unable to retrieve request info from request")
+		a.next.ServeHTTP(w, req)
+		return
+	}
+
+	// Auditing should ignore k8s request when k8s auditing is enabled.
+	if info.IsKubernetesRequest && a.K8sAuditingEnabled() {
+		a.next.ServeHTTP(w, req)
+		return
+	}
+
+	if event := a.LogRequestObject(req, info); event != nil {
+		resp := auditing.NewResponseCapture(w)
+		a.next.ServeHTTP(resp, req)
+		go a.LogResponseObject(event, resp)
+	} else {
+		a.next.ServeHTTP(w, req)
+	}
 }

pkg/apiserver/filters/authentication.go

@@ -32,41 +32,51 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 )
 
+type authnFilter struct {
+	next http.Handler
+	authenticator.Request
+	serializer runtime.NegotiatedSerializer
+}
+
 // WithAuthentication installs authentication handler to handler chain.
 // The following part is a little bit ugly, WithAuthentication also logs user failed login attempt
 // if using basic auth. But only treats request with requestURI `/oauth/authorize` as login attempt
-func WithAuthentication(handler http.Handler, authRequest authenticator.Request) http.Handler {
-	if authRequest == nil {
+func WithAuthentication(next http.Handler, authenticator authenticator.Request) http.Handler {
+	if authenticator == nil {
 		klog.Warningf("Authentication is disabled")
-		return handler
+		return next
 	}
-	s := serializer.NewCodecFactory(runtime.NewScheme()).WithoutConversion()
+	return &authnFilter{
+		next:       next,
+		Request:    authenticator,
+		serializer: serializer.NewCodecFactory(runtime.NewScheme()).WithoutConversion(),
+	}
+}
 
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		resp, ok, err := authRequest.AuthenticateRequest(req)
-		_, _, usingBasicAuth := req.BasicAuth()
+func (a *authnFilter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	resp, ok, err := a.AuthenticateRequest(req)
+	_, _, usingBasicAuth := req.BasicAuth()
 
-		defer func() {
-			// if we authenticated successfully, go ahead and remove the bearer token so that no one
-			// is ever tempted to use it inside of the API server
-			if usingBasicAuth && ok {
-				req.Header.Del("Authorization")
-			}
-		}()
+	defer func() {
+		// if we authenticated successfully, go ahead and remove the bearer token so that no one
+		// is ever tempted to use it inside the API server
+		if usingBasicAuth && ok {
+			req.Header.Del("Authorization")
+		}
+	}()
 
-		if err != nil || !ok {
-			ctx := req.Context()
-			requestInfo, found := request.RequestInfoFrom(ctx)
-			if !found {
-				responsewriters.InternalError(w, req, errors.New("no RequestInfo found in the context"))
-				return
-			}
-			gv := schema.GroupVersion{Group: requestInfo.APIGroup, Version: requestInfo.APIVersion}
-			responsewriters.ErrorNegotiated(apierrors.NewUnauthorized(fmt.Sprintf("Unauthorized: %s", err)), s, gv, w, req)
+	if err != nil || !ok {
+		ctx := req.Context()
+		requestInfo, found := request.RequestInfoFrom(ctx)
+		if !found {
+			responsewriters.InternalError(w, req, errors.New("no RequestInfo found in the context"))
 			return
 		}
+		gv := schema.GroupVersion{Group: requestInfo.APIGroup, Version: requestInfo.APIVersion}
+		responsewriters.ErrorNegotiated(apierrors.NewUnauthorized(fmt.Sprintf("Unauthorized: %s", err)), a.serializer, gv, w, req)
+		return
+	}
 
-		req = req.WithContext(request.WithUser(req.Context(), resp.User))
-		handler.ServeHTTP(w, req)
-	})
+	req = req.WithContext(request.WithUser(req.Context(), resp.User))
+	a.next.ServeHTTP(w, req)
 }

pkg/apiserver/filters/authorization.go

@@ -30,37 +30,46 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 )
 
+type authzFilter struct {
+	next http.Handler
+	authorizer.Authorizer
+	serializer runtime.NegotiatedSerializer
+}
+
 // WithAuthorization passes all authorized requests on to handler, and returns forbidden error otherwise.
-func WithAuthorization(handler http.Handler, authorizers authorizer.Authorizer) http.Handler {
+func WithAuthorization(next http.Handler, authorizers authorizer.Authorizer) http.Handler {
 	if authorizers == nil {
 		klog.Warningf("Authorization is disabled")
-		return handler
+		return next
 	}
 
-	defaultSerializer := serializer.NewCodecFactory(runtime.NewScheme()).WithoutConversion()
+	return &authzFilter{
+		next:       next,
+		Authorizer: authorizers,
+		serializer: serializer.NewCodecFactory(runtime.NewScheme()).WithoutConversion(),
+	}
+}
 
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		ctx := req.Context()
+func (a *authzFilter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	ctx := req.Context()
+	attributes, err := getAuthorizerAttributes(ctx)
+	if err != nil {
+		responsewriters.InternalError(w, req, err)
+	}
 
-		attributes, err := getAuthorizerAttributes(ctx)
-		if err != nil {
-			responsewriters.InternalError(w, req, err)
-		}
+	authorized, reason, err := a.Authorize(attributes)
+	if authorized == authorizer.DecisionAllow {
+		a.next.ServeHTTP(w, req)
+		return
+	}
 
-		authorized, reason, err := authorizers.Authorize(attributes)
-		if authorized == authorizer.DecisionAllow {
-			handler.ServeHTTP(w, req)
-			return
-		}
+	if err != nil {
+		responsewriters.InternalError(w, req, err)
+		return
+	}
 
-		if err != nil {
-			responsewriters.InternalError(w, req, err)
-			return
-		}
-
-		klog.V(4).Infof("Forbidden: %#v, Reason: %q", req.RequestURI, reason)
-		responsewriters.Forbidden(ctx, attributes, w, req, reason, defaultSerializer)
-	})
+	klog.V(4).Infof("Forbidden: %#v, Reason: %q", req.RequestURI, reason)
+	responsewriters.Forbidden(ctx, attributes, w, req, reason, a.serializer)
 }
 
 func getAuthorizerAttributes(ctx context.Context) (authorizer.Attributes, error) {

pkg/apiserver/filters/dispatch.go

@@ -1,50 +0,0 @@
-/*
-Copyright 2020 The KubeSphere 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 filters
-
-import (
-	"fmt"
-	"net/http"
-
-	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
-	"k8s.io/klog/v2"
-
-	"kubesphere.io/kubesphere/pkg/apiserver/dispatch"
-	"kubesphere.io/kubesphere/pkg/apiserver/request"
-)
-
-// Multiple cluster dispatcher forward request to desired cluster based on request cluster name
-// which included in request path clusters/{cluster}
-func WithMultipleClusterDispatcher(handler http.Handler, dispatch dispatch.Dispatcher) http.Handler {
-	if dispatch == nil {
-		klog.V(4).Infof("Multiple cluster dispatcher is disabled")
-		return handler
-	}
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		info, ok := request.RequestInfoFrom(req.Context())
-		if !ok {
-			responsewriters.InternalError(w, req, fmt.Errorf(""))
-			return
-		}
-
-		if info.Cluster == "" {
-			handler.ServeHTTP(w, req)
-		} else {
-			dispatch.Dispatch(w, req, handler)
-		}
-	})
-}

pkg/apiserver/filters/dynamicresource.go

@@ -0,0 +1,95 @@
+package filters
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/emicklei/go-restful"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
+
+	"kubesphere.io/kubesphere/pkg/api"
+	"kubesphere.io/kubesphere/pkg/apiserver/query"
+	"kubesphere.io/kubesphere/pkg/apiserver/request"
+	"kubesphere.io/kubesphere/pkg/models/resources/v1beta1"
+)
+
+type DynamicResourceHandler struct {
+	v1beta1.ResourceManager
+	serviceErrorHandleFallback restful.ServiceErrorHandleFunction
+}
+
+func NewDynamicResourceHandle(serviceErrorHandleFallback restful.ServiceErrorHandleFunction, resourceGetter v1beta1.ResourceManager) *DynamicResourceHandler {
+	return &DynamicResourceHandler{
+		ResourceManager:            resourceGetter,
+		serviceErrorHandleFallback: serviceErrorHandleFallback,
+	}
+}
+
+func (d *DynamicResourceHandler) HandleServiceError(serviceError restful.ServiceError, req *restful.Request, w *restful.Response) {
+	// only not found error will be handled
+	if serviceError.Code != http.StatusNotFound {
+		d.serviceErrorHandleFallback(serviceError, req, w)
+		return
+	}
+
+	// TODO support write operation and workspace scope API
+	if req.Request.Method != http.MethodGet {
+		d.serviceErrorHandleFallback(serviceError, req, w)
+		return
+	}
+
+	reqInfo, exist := request.RequestInfoFrom(req.Request.Context())
+	if !exist {
+		responsewriters.InternalError(w, req.Request, fmt.Errorf("no RequestInfo found in the context"))
+		return
+	}
+
+	if reqInfo.IsKubernetesRequest {
+		d.serviceErrorHandleFallback(serviceError, req, w)
+		return
+	}
+
+	gvr := schema.GroupVersionResource{
+		Group:    reqInfo.APIGroup,
+		Version:  reqInfo.APIVersion,
+		Resource: reqInfo.Resource,
+	}
+
+	if gvr.Group == "" ||
+		gvr.Version == "" ||
+		gvr.Resource == "" {
+		d.serviceErrorHandleFallback(serviceError, req, w)
+		return
+	}
+
+	served, err := d.IsServed(gvr)
+	if err != nil {
+		responsewriters.InternalError(w, req.Request, err)
+		return
+	}
+
+	if !served {
+		d.serviceErrorHandleFallback(serviceError, req, w)
+		return
+	}
+
+	var result interface{}
+	if reqInfo.Verb == "list" {
+		result, err = d.ListResources(req.Request.Context(), gvr, reqInfo.Namespace, query.ParseQueryParameter(req))
+	} else {
+		result, err = d.GetResource(req.Request.Context(), gvr, reqInfo.Name, reqInfo.Namespace)
+	}
+
+	if err != nil {
+		if meta.IsNoMatchError(err) {
+			d.serviceErrorHandleFallback(serviceError, req, w)
+			return
+		}
+		api.HandleError(w, req, err)
+		return
+	}
+
+	w.WriteAsJson(result)
+}

pkg/apiserver/filters/kubeapiserver.go

@@ -17,6 +17,7 @@ limitations under the License.
 package filters
 
 import (
+	"fmt"
 	"net/http"
 	"net/url"
 
@@ -26,39 +27,48 @@ import (
 	"k8s.io/klog/v2"
 
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
-	"kubesphere.io/kubesphere/pkg/server/errors"
 )
 
+type kubeAPIProxy struct {
+	next          http.Handler
+	kubeAPIServer *url.URL
+	transport     http.RoundTripper
+}
+
 // WithKubeAPIServer proxy request to kubernetes service if requests path starts with /api
-func WithKubeAPIServer(handler http.Handler, config *rest.Config, failed proxy.ErrorResponder) http.Handler {
-	kubernetes, _ := url.Parse(config.Host)
-	defaultTransport, err := rest.TransportFor(config)
+func WithKubeAPIServer(next http.Handler, config *rest.Config) http.Handler {
+	kubeAPIServer, _ := url.Parse(config.Host)
+	transport, err := rest.TransportFor(config)
 	if err != nil {
 		klog.Errorf("Unable to create transport from rest.Config: %v", err)
-		return handler
+		return next
+	}
+	return &kubeAPIProxy{
+		next:          next,
+		kubeAPIServer: kubeAPIServer,
+		transport:     transport,
+	}
+}
+
+func (k kubeAPIProxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	info, ok := request.RequestInfoFrom(req.Context())
+	if !ok {
+		responsewriters.InternalError(w, req, fmt.Errorf("no RequestInfo found in the context"))
+		return
 	}
 
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		info, ok := request.RequestInfoFrom(req.Context())
-		if !ok {
-			err := errors.New("Unable to retrieve request info from request")
-			klog.Error(err)
-			responsewriters.InternalError(w, req, err)
-		}
+	if info.IsKubernetesRequest {
+		s := *req.URL
+		s.Host = k.kubeAPIServer.Host
+		s.Scheme = k.kubeAPIServer.Scheme
 
-		if info.IsKubernetesRequest {
-			s := *req.URL
-			s.Host = kubernetes.Host
-			s.Scheme = kubernetes.Scheme
+		// make sure we don't override kubernetes's authorization
+		req.Header.Del("Authorization")
+		httpProxy := proxy.NewUpgradeAwareHandler(&s, k.transport, true, false, &responder{})
+		httpProxy.UpgradeTransport = proxy.NewUpgradeRequestRoundTripper(k.transport, k.transport)
+		httpProxy.ServeHTTP(w, req)
+		return
+	}
 
-			// make sure we don't override kubernetes's authorization
-			req.Header.Del("Authorization")
-			httpProxy := proxy.NewUpgradeAwareHandler(&s, defaultTransport, true, false, failed)
-			httpProxy.UpgradeTransport = proxy.NewUpgradeRequestRoundTripper(defaultTransport, defaultTransport)
-			httpProxy.ServeHTTP(w, req)
-			return
-		}
-
-		handler.ServeHTTP(w, req)
-	})
+	k.next.ServeHTTP(w, req)
 }

pkg/apiserver/filters/middleware.go

@@ -1,21 +0,0 @@
-package filters
-
-import "net/http"
-
-type Middleware interface {
-	Handle(w http.ResponseWriter, req *http.Request) bool
-}
-
-func WithMiddleware(next http.Handler, middlewares ...Middleware) http.Handler {
-	if middlewares == nil {
-		return next
-	}
-	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		for _, middleware := range middlewares {
-			if middleware.Handle(w, req) {
-				return
-			}
-		}
-		next.ServeHTTP(w, req)
-	})
-}

pkg/apiserver/filters/multicluster.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package dispatch
+package filters
 
 import (
 	"fmt"
@@ -26,7 +26,6 @@ import (
 	"k8s.io/apimachinery/pkg/util/proxy"
 	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
 	"k8s.io/klog/v2"
-
 	clusterv1alpha1 "kubesphere.io/api/cluster/v1alpha1"
 
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
@@ -35,56 +34,60 @@ import (
 
 const proxyURLFormat = "/api/v1/namespaces/kubesphere-system/services/:ks-apiserver:/proxy%s"
 
-// Dispatcher defines how to forward request to designated cluster based on cluster name
-// This should only be used in host cluster when multicluster mode enabled, use in any other cases may cause
-// unexpected behavior
-type Dispatcher interface {
-	Dispatch(w http.ResponseWriter, req *http.Request, handler http.Handler)
-}
-
-type clusterDispatch struct {
+type multiclusterDispatcher struct {
+	next http.Handler
 	clusterclient.ClusterClients
 }
 
-func NewClusterDispatch(cc clusterclient.ClusterClients) Dispatcher {
-	return &clusterDispatch{cc}
+// WithMulticluster forward request to desired cluster based on request cluster name
+// which included in request path clusters/{cluster}
+func WithMulticluster(next http.Handler, clusterClient clusterclient.ClusterClients) http.Handler {
+	if clusterClient == nil {
+		klog.V(4).Infof("Multicluster dispatcher is disabled")
+		return next
+	}
+	return &multiclusterDispatcher{
+		next:           next,
+		ClusterClients: clusterClient,
+	}
 }
 
-// Dispatch dispatch requests to designated cluster
-func (c *clusterDispatch) Dispatch(w http.ResponseWriter, req *http.Request, handler http.Handler) {
-	info, _ := request.RequestInfoFrom(req.Context())
-
-	if len(info.Cluster) == 0 {
-		klog.Warningf("Request with empty cluster, %v", req.URL)
-		http.Error(w, "Bad request, empty cluster", http.StatusBadRequest)
+func (m *multiclusterDispatcher) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	info, ok := request.RequestInfoFrom(req.Context())
+	if !ok {
+		responsewriters.InternalError(w, req, fmt.Errorf("no RequestInfo found in the context"))
+		return
+	}
+	if info.Cluster == "" {
+		m.next.ServeHTTP(w, req)
 		return
 	}
 
-	cluster, err := c.Get(info.Cluster)
+	cluster, err := m.Get(info.Cluster)
 	if err != nil {
 		if errors.IsNotFound(err) {
-			http.Error(w, fmt.Sprintf("cluster %s not found", info.Cluster), http.StatusNotFound)
+			responsewriters.WriteRawJSON(http.StatusBadRequest, errors.NewBadRequest(fmt.Sprintf("cluster %s not exists", info.Cluster)), w)
 		} else {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
+			responsewriters.InternalError(w, req, err)
 		}
 		return
 	}
 
 	// request cluster is host cluster, no need go through agent
-	if c.IsHostCluster(cluster) {
+	if m.IsHostCluster(cluster) {
 		req.URL.Path = strings.Replace(req.URL.Path, fmt.Sprintf("/clusters/%s", info.Cluster), "", 1)
-		handler.ServeHTTP(w, req)
+		m.next.ServeHTTP(w, req)
 		return
 	}
 
-	if !c.IsClusterReady(cluster) {
-		http.Error(w, fmt.Sprintf("cluster %s is not ready", cluster.Name), http.StatusBadRequest)
+	if !m.IsClusterReady(cluster) {
+		responsewriters.InternalError(w, req, fmt.Errorf("cluster %s is not ready", cluster.Name))
 		return
 	}
 
-	innCluster := c.GetInnerCluster(cluster.Name)
+	innCluster := m.GetInnerCluster(cluster.Name)
 	if innCluster == nil {
-		http.Error(w, fmt.Sprintf("cluster %s is not ready", cluster.Name), http.StatusBadRequest)
+		responsewriters.InternalError(w, req, fmt.Errorf("cluster %s is not ready", cluster.Name))
 		return
 	}
 
@@ -135,16 +138,11 @@ func (c *clusterDispatch) Dispatch(w http.ResponseWriter, req *http.Request, han
 		}
 	} else {
 		// everything else goes to ks-apiserver, since our ks-apiserver has the ability to proxy kube-apiserver requests
-
 		u.Host = innCluster.KubesphereURL.Host
 		u.Scheme = innCluster.KubesphereURL.Scheme
 	}
 
-	httpProxy := proxy.NewUpgradeAwareHandler(&u, transport, false, false, c)
+	httpProxy := proxy.NewUpgradeAwareHandler(&u, transport, false, false, &responder{})
 	httpProxy.UpgradeTransport = proxy.NewUpgradeRequestRoundTripper(transport, transport)
 	httpProxy.ServeHTTP(w, req)
 }
-
-func (c *clusterDispatch) Error(w http.ResponseWriter, req *http.Request, err error) {
-	responsewriters.InternalError(w, req, err)
-}

pkg/apiserver/filters/requestinfo.go

@@ -26,7 +26,7 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/request"
 )
 
-func WithRequestInfo(handler http.Handler, resolver request.RequestInfoResolver) http.Handler {
+func WithRequestInfo(next http.Handler, resolver request.RequestInfoResolver) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		// KubeSphere supports kube-apiserver proxy requests in multicluster mode. But kube-apiserver
 		// stripped all authorization headers. Use custom header to carry token to avoid losing authentication token.
@@ -66,6 +66,6 @@ func WithRequestInfo(handler http.Handler, resolver request.RequestInfoResolver)
 		}
 
 		req = req.WithContext(request.WithRequestInfo(ctx, info))
-		handler.ServeHTTP(w, req)
+		next.ServeHTTP(w, req)
 	})
 }

pkg/apiserver/filters/responder.go

@@ -0,0 +1,14 @@
+package filters
+
+import (
+	"net/http"
+
+	"k8s.io/klog/v2"
+)
+
+type responder struct{}
+
+func (r *responder) Error(w http.ResponseWriter, req *http.Request, err error) {
+	klog.Errorf("Error while proxying request: %v", err)
+	http.Error(w, err.Error(), http.StatusInternalServerError)
+}

pkg/apiserver/proxies/unregistered.go

@@ -1,108 +0,0 @@
-package proxies
-
-import (
-	"fmt"
-	"net/http"
-	"strings"
-
-	"github.com/emicklei/go-restful"
-	"k8s.io/apimachinery/pkg/runtime/schema"
-	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/klog/v2"
-
-	"kubesphere.io/kubesphere/pkg/api"
-	"kubesphere.io/kubesphere/pkg/apiserver/filters"
-	"kubesphere.io/kubesphere/pkg/apiserver/query"
-	"kubesphere.io/kubesphere/pkg/apiserver/request"
-	"kubesphere.io/kubesphere/pkg/models/resources/v1beta1"
-)
-
-type unregisteredMiddleware struct {
-	registeredGv   sets.String
-	resourceGetter v1beta1.ResourceGetter
-}
-
-func NewUnregisteredMiddleware(c *restful.Container, resourceGetter v1beta1.ResourceGetter) filters.Middleware {
-	middleware := &unregisteredMiddleware{
-		registeredGv:   sets.NewString(),
-		resourceGetter: resourceGetter,
-	}
-
-	for _, ws := range c.RegisteredWebServices() {
-		rootPath := ws.RootPath()
-		if strings.HasPrefix(rootPath, "/kapis") {
-			middleware.registeredGv.Insert(rootPath)
-		}
-	}
-
-	return middleware
-}
-
-func (u *unregisteredMiddleware) Handle(w http.ResponseWriter, req *http.Request) bool {
-	if req.Method != http.MethodGet {
-		return false
-	}
-
-	reqInfo, exist := request.RequestInfoFrom(req.Context())
-	if !exist {
-		return false
-	}
-
-	if reqInfo.IsKubernetesRequest {
-		return false
-	}
-
-	gvr := schema.GroupVersionResource{
-		Group:    reqInfo.APIGroup,
-		Version:  reqInfo.APIVersion,
-		Resource: reqInfo.Resource,
-	}
-
-	if gvr.Group == "" ||
-		gvr.Version == "" ||
-		gvr.Resource == "" {
-		return false
-	}
-
-	rootPath := fmt.Sprintf("/kapis/%s/%s", gvr.Group, gvr.Version)
-	if u.registeredGv.Has(rootPath) {
-		return false
-	}
-
-	var (
-		listReq bool
-		q       *query.Query
-	)
-	restfulReq := restful.NewRequest(req)
-	restfulResp := restful.NewResponse(w)
-	if reqInfo.Name == "" {
-		listReq = true
-		q = query.ParseQueryParameter(restfulReq)
-	}
-
-	var (
-		result interface{}
-		err    error
-	)
-	if listReq {
-		result, err = u.resourceGetter.ListResources(gvr, reqInfo.Namespace, q)
-	} else {
-		result, err = u.resourceGetter.GetResource(gvr, reqInfo.Name, reqInfo.Namespace)
-	}
-	handleResponse(result, err, restfulResp, restfulReq)
-	return true
-}
-
-func handleResponse(result interface{}, err error, resp *restful.Response, req *restful.Request) {
-	resp.SetRequestAccepts(restful.MIME_JSON)
-	if err != nil {
-		if err == v1beta1.ErrResourceNotSupported {
-			api.HandleBadRequest(resp, req, err)
-			return
-		}
-		klog.Error(err)
-		api.HandleError(resp, req, err)
-		return
-	}
-	resp.WriteEntity(result)
-}

pkg/models/resources/v1beta1/cache.go

@@ -1,66 +0,0 @@
-package v1beta1
-
-import (
-	"context"
-
-	"k8s.io/apimachinery/pkg/api/meta"
-	"k8s.io/apimachinery/pkg/runtime"
-	"sigs.k8s.io/controller-runtime/pkg/cache"
-	"sigs.k8s.io/controller-runtime/pkg/client"
-
-	"kubesphere.io/kubesphere/pkg/apiserver/query"
-)
-
-type resourceCache struct {
-	cache cache.Cache
-}
-
-func NewResourceCache(cache cache.Cache) Interface {
-	return &resourceCache{cache: cache}
-}
-
-func (u *resourceCache) Get(namespace, name string, object client.Object) error {
-	return u.cache.Get(context.Background(), client.ObjectKey{Namespace: namespace, Name: name}, object)
-}
-
-func (u *resourceCache) List(namespace string, query *query.Query, list client.ObjectList) error {
-	listOpt := &client.ListOptions{
-		LabelSelector: query.Selector(),
-		Namespace:     namespace,
-	}
-	err := u.cache.List(context.Background(), list, listOpt)
-	if err != nil {
-		return err
-	}
-
-	extractList, err := meta.ExtractList(list)
-	if err != nil {
-		return err
-	}
-
-	filtered := DefaultList(extractList, query, compare, filter)
-	if err := meta.SetList(list, filtered); err != nil {
-		return err
-	}
-	return nil
-}
-
-func compare(left, right runtime.Object, field query.Field) bool {
-	l, err := meta.Accessor(left)
-	if err != nil {
-		return false
-	}
-	r, err := meta.Accessor(right)
-	if err != nil {
-		return false
-	}
-	return DefaultObjectMetaCompare(l, r, field)
-}
-
-func filter(object runtime.Object, filter query.Filter) bool {
-	o, err := meta.Accessor(object)
-	if err != nil {
-		return false
-	}
-	return DefaultObjectMetaFilter(o, filter)
-}

pkg/models/resources/v1beta1/interface.go

@@ -1,6 +1,7 @@
 package v1beta1
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"sort"
@@ -18,27 +19,22 @@ import (
 	"kubesphere.io/kubesphere/pkg/apiserver/query"
 )
 
-type Interface interface {
-	// Get retrieves a single object by its namespace and name
-	Get(namespace, name string, object client.Object) error
-
-	// List retrieves a collection of objects matches given query
-	List(namespace string, query *query.Query, object client.ObjectList) error
+type ResourceManager interface {
+	IsServed(schema.GroupVersionResource) (bool, error)
+	GetResource(ctx context.Context, gvr schema.GroupVersionResource, namespace string, name string) (client.Object, error)
+	ListResources(ctx context.Context, gvr schema.GroupVersionResource, namespace string, query *query.Query) (client.ObjectList, error)
+	Get(ctx context.Context, namespace, name string, object client.Object) error
+	List(ctx context.Context, namespace string, query *query.Query, object client.ObjectList) error
 }
 
-type ResourceGetter interface {
-	GetResource(schema.GroupVersionResource, string, string) (client.Object, error)
-	ListResources(schema.GroupVersionResource, string, *query.Query) (client.ObjectList, error)
-}
-
-// CompareFunc return true is left great than right
+// CompareFunc return true is left greater than right
 type CompareFunc func(runtime.Object, runtime.Object, query.Field) bool
 
 type FilterFunc func(runtime.Object, query.Filter) bool
 
 type TransformFunc func(runtime.Object) runtime.Object
 
-func DefaultList(objects []runtime.Object, q *query.Query, compareFunc CompareFunc, filterFunc FilterFunc, transformFuncs ...TransformFunc) []runtime.Object {
+func DefaultList(objects []runtime.Object, q *query.Query, compareFunc CompareFunc, filterFunc FilterFunc, transformFuncs ...TransformFunc) ([]runtime.Object, *int64) {
 	// selected matched ones
 	var filtered []runtime.Object
 	if len(q.Filters) != 0 {
@@ -77,11 +73,12 @@ func DefaultList(objects []runtime.Object, q *query.Query, compareFunc CompareFu
 	}
 
 	start, end := q.Pagination.GetValidPagination(total)
+	remainingItemCount := int64(total - end)
 
-	return filtered[start:end]
+	return filtered[start:end], &remainingItemCount
 }
 
-// DefaultObjectMetaCompare return true is left great than right
+// DefaultObjectMetaCompare return true is left greater than right
 func DefaultObjectMetaCompare(left, right metav1.Object, sortBy query.Field) bool {
 	switch sortBy {
 	// ?sortBy=name

pkg/models/resources/v1beta1/resourcelgetter.go

@@ -1,150 +0,0 @@
-package v1beta1
-
-import (
-	"context"
-	"errors"
-	"strings"
-	"sync"
-
-	"sigs.k8s.io/controller-runtime/pkg/cache"
-
-	"kubesphere.io/kubesphere/pkg/apiserver/query"
-
-	extv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
-	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
-	"k8s.io/apimachinery/pkg/runtime/schema"
-	"sigs.k8s.io/controller-runtime/pkg/client"
-)
-
-var ErrResourceNotSupported = errors.New("resource is not supported")
-var ErrResourceNotServed = errors.New("resource is not served")
-
-const labelResourceServed = "kubesphere.io/resource-served"
-
-// TODO If delete the crd at the cluster when ks is running, the client.cache doesn`t return err but empty result
-func New(client client.Client, cache cache.Cache) ResourceGetter {
-	return &resourceGetter{
-		client:   client,
-		cache:    NewResourceCache(cache),
-		serveCRD: make(map[string]bool, 0),
-	}
-}
-
-type resourceGetter struct {
-	client   client.Client
-	cache    Interface
-	serveCRD map[string]bool
-	sync.RWMutex
-}
-
-func (h *resourceGetter) GetResource(gvr schema.GroupVersionResource, name, namespace string) (client.Object, error) {
-	var obj client.Object
-	gvk, err := h.getGVK(gvr)
-	if err != nil {
-		return nil, err
-	}
-
-	if h.client.Scheme().Recognizes(gvk) {
-		gvkObject, err := h.client.Scheme().New(gvk)
-		if err != nil {
-			return nil, err
-		}
-		obj = gvkObject.(client.Object)
-	} else {
-		serviced, err := h.isServed(gvr)
-		if err != nil {
-			return nil, err
-		}
-		if !serviced {
-			return nil, ErrResourceNotServed
-		}
-
-		u := &unstructured.Unstructured{}
-		u.SetGroupVersionKind(gvk)
-		obj = u
-	}
-
-	if err := h.cache.Get(namespace, name, obj); err != nil {
-		return nil, err
-	}
-	return obj, nil
-}
-
-func (h *resourceGetter) ListResources(gvr schema.GroupVersionResource, namespace string, query *query.Query) (client.ObjectList, error) {
-	var obj client.ObjectList
-
-	gvk, err := h.getGVK(gvr)
-	if err != nil {
-		return nil, err
-	}
-
-	gvk = convertGVKToList(gvk)
-
-	if h.client.Scheme().Recognizes(gvk) {
-		gvkObject, err := h.client.Scheme().New(gvk)
-		if err != nil {
-			return nil, err
-		}
-		obj = gvkObject.(client.ObjectList)
-	} else {
-		serviced, err := h.isServed(gvr)
-		if err != nil {
-			return nil, err
-		}
-		if !serviced {
-			return nil, ErrResourceNotServed
-		}
-		u := &unstructured.UnstructuredList{}
-		u.SetGroupVersionKind(gvk)
-		obj = u
-	}
-
-	if err := h.cache.List(namespace, query, obj); err != nil {
-		return nil, err
-	}
-	return obj, nil
-}
-
-func convertGVKToList(gvk schema.GroupVersionKind) schema.GroupVersionKind {
-	if strings.HasSuffix(gvk.Kind, "List") {
-		return gvk
-	}
-	gvk.Kind = gvk.Kind + "List"
-	return gvk
-}
-
-func (h *resourceGetter) getGVK(gvr schema.GroupVersionResource) (schema.GroupVersionKind, error) {
-	var (
-		gvk schema.GroupVersionKind
-		err error
-	)
-	gvk, err = h.client.RESTMapper().KindFor(gvr)
-	if err != nil {
-		return gvk, err
-	}
-
-	return gvk, nil
-}
-
-func (h *resourceGetter) isServed(gvr schema.GroupVersionResource) (bool, error) {
-	resourceName := gvr.Resource + "." + gvr.Group
-	h.RWMutex.RLock()
-	isServed := h.serveCRD[resourceName]
-	h.RWMutex.RUnlock()
-	if isServed {
-		return true, nil
-	}
-
-	crd := &extv1.CustomResourceDefinition{}
-	err := h.client.Get(context.Background(), client.ObjectKey{Name: resourceName}, crd)
-	if err != nil {
-		return false, err
-	}
-	if crd.Labels[labelResourceServed] == "true" {
-		h.RWMutex.Lock()
-		h.serveCRD[resourceName] = true
-		h.RWMutex.Unlock()
-		return true, nil
-	}
-	return false, nil
-}

pkg/models/resources/v1beta1/resourcemanager.go

@@ -0,0 +1,175 @@
+package v1beta1
+
+import (
+	"context"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
+
+	"kubesphere.io/kubesphere/pkg/apiserver/query"
+
+	extv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+const labelResourceServed = "kubesphere.io/resource-served"
+
+// TODO If delete the crd at the cluster when ks is running, the client.cache doesn`t return err but empty result
+func New(client client.Client, cache cache.Cache) ResourceManager {
+	return &resourceManager{
+		client: client,
+		cache:  cache,
+	}
+}
+
+type resourceManager struct {
+	client client.Client
+	cache  cache.Cache
+}
+
+func (h *resourceManager) GetResource(ctx context.Context, gvr schema.GroupVersionResource, namespace, name string) (client.Object, error) {
+	var obj client.Object
+	gvk, err := h.getGVK(gvr)
+	if err != nil {
+		return nil, err
+	}
+
+	if h.client.Scheme().Recognizes(gvk) {
+		gvkObject, err := h.client.Scheme().New(gvk)
+		if err != nil {
+			return nil, err
+		}
+		obj = gvkObject.(client.Object)
+	} else {
+		u := &unstructured.Unstructured{}
+		u.SetGroupVersionKind(gvk)
+		obj = u
+	}
+
+	if err := h.Get(ctx, namespace, name, obj); err != nil {
+		return nil, err
+	}
+	return obj, nil
+}
+
+func (h *resourceManager) ListResources(ctx context.Context, gvr schema.GroupVersionResource, namespace string, query *query.Query) (client.ObjectList, error) {
+	var obj client.ObjectList
+
+	gvk, err := h.getGVK(gvr)
+	if err != nil {
+		return nil, err
+	}
+
+	gvk = convertGVKToList(gvk)
+
+	if h.client.Scheme().Recognizes(gvk) {
+		gvkObject, err := h.client.Scheme().New(gvk)
+		if err != nil {
+			return nil, err
+		}
+		obj = gvkObject.(client.ObjectList)
+	} else {
+		u := &unstructured.UnstructuredList{}
+		u.SetGroupVersionKind(gvk)
+		obj = u
+	}
+
+	if err := h.List(ctx, namespace, query, obj); err != nil {
+		return nil, err
+	}
+	return obj, nil
+}
+
+func convertGVKToList(gvk schema.GroupVersionKind) schema.GroupVersionKind {
+	if strings.HasSuffix(gvk.Kind, "List") {
+		return gvk
+	}
+	gvk.Kind = gvk.Kind + "List"
+	return gvk
+}
+
+func (h *resourceManager) getGVK(gvr schema.GroupVersionResource) (schema.GroupVersionKind, error) {
+	var (
+		gvk schema.GroupVersionKind
+		err error
+	)
+	gvk, err = h.client.RESTMapper().KindFor(gvr)
+	if err != nil {
+		return gvk, err
+	}
+	return gvk, nil
+}
+
+func (h *resourceManager) IsServed(gvr schema.GroupVersionResource) (bool, error) {
+	// well-known group version is already registered
+	if h.client.Scheme().IsVersionRegistered(gvr.GroupVersion()) {
+		return true, nil
+	}
+
+	crd := &extv1.CustomResourceDefinition{}
+	if err := h.cache.Get(context.Background(), client.ObjectKey{Name: gvr.GroupResource().String()}, crd); err != nil {
+		if errors.IsNotFound(err) {
+			return false, nil
+		}
+		return false, err
+	}
+
+	if crd.Labels[labelResourceServed] == "true" {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+func (h *resourceManager) Get(ctx context.Context, namespace, name string, object client.Object) error {
+	return h.cache.Get(ctx, client.ObjectKey{Namespace: namespace, Name: name}, object)
+}
+
+func (h *resourceManager) List(ctx context.Context, namespace string, query *query.Query, list client.ObjectList) error {
+	listOpt := &client.ListOptions{
+		LabelSelector: query.Selector(),
+		Namespace:     namespace,
+	}
+
+	err := h.cache.List(ctx, list, listOpt)
+	if err != nil {
+		return err
+	}
+
+	extractList, err := meta.ExtractList(list)
+	if err != nil {
+		return err
+	}
+
+	filtered, remainingItemCount := DefaultList(extractList, query, compare, filter)
+	list.SetRemainingItemCount(remainingItemCount)
+	if err := meta.SetList(list, filtered); err != nil {
+		return err
+	}
+	return nil
+}
+
+func compare(left, right runtime.Object, field query.Field) bool {
+	l, err := meta.Accessor(left)
+	if err != nil {
+		return false
+	}
+	r, err := meta.Accessor(right)
+	if err != nil {
+		return false
+	}
+	return DefaultObjectMetaCompare(l, r, field)
+}
+
+func filter(object runtime.Object, filter query.Filter) bool {
+	o, err := meta.Accessor(object)
+	if err != nil {
+		return false
+	}
+	return DefaultObjectMetaFilter(o, filter)
+}