add service status detection to kubernetes-discovery

cmd/kubernetes-discovery/artifacts/local-cluster-up/kubernetes-discover-pod.yaml

@@ -17,6 +17,24 @@ spec:
       - name: kubernetes-discovery
         image: kubernetes-discovery:latest
         imagePullPolicy: Never
+        livenessProbe:
+          failureThreshold: 3
+          httpGet:
+            path: /version
+            port: 443
+            scheme: HTTPS
+          periodSeconds: 10
+          successThreshold: 1
+          timeoutSeconds: 1
+        readinessProbe:
+          failureThreshold: 3
+          httpGet:
+            path: /version
+            port: 443
+            scheme: HTTPS
+          periodSeconds: 10
+          successThreshold: 1
+          timeoutSeconds: 1
         args:
         - "--proxy-client-cert-file=/var/run/auth-proxy-client/tls.crt"
         - "--proxy-client-key-file=/var/run/auth-proxy-client/tls.key"

cmd/kubernetes-discovery/pkg/apiserver/BUILD

@@ -34,6 +34,9 @@ go_library(
         "//pkg/apiserver/filters:go_default_library",
         "//pkg/auth/handlers:go_default_library",
         "//pkg/client/cache:go_default_library",
+        "//pkg/client/clientset_generated/clientset:go_default_library",
+        "//pkg/client/informers/informers_generated:go_default_library",
+        "//pkg/client/listers/core/v1:go_default_library",
         "//pkg/client/restclient:go_default_library",
         "//pkg/client/transport:go_default_library",
         "//pkg/controller:go_default_library",
@@ -64,10 +67,12 @@ go_test(
         "//cmd/kubernetes-discovery/pkg/apis/apiregistration:go_default_library",
         "//cmd/kubernetes-discovery/pkg/client/listers/apiregistration/internalversion:go_default_library",
         "//pkg/api:go_default_library",
+        "//pkg/api/v1:go_default_library",
         "//pkg/apis/meta/v1:go_default_library",
         "//pkg/apiserver/request:go_default_library",
         "//pkg/auth/user:go_default_library",
         "//pkg/client/cache:go_default_library",
+        "//pkg/client/listers/core/v1:go_default_library",
         "//pkg/runtime:go_default_library",
         "//pkg/util/diff:go_default_library",
         "//pkg/util/sets:go_default_library",

cmd/kubernetes-discovery/pkg/apiserver/apiserver.go

@@ -25,6 +25,9 @@ import (
 	"k8s.io/kubernetes/pkg/api/rest"
 	apiserverfilters "k8s.io/kubernetes/pkg/apiserver/filters"
 	authhandlers "k8s.io/kubernetes/pkg/auth/handlers"
+	kubeclientset "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
+	kubeinformers "k8s.io/kubernetes/pkg/client/informers/informers_generated"
+	v1listers "k8s.io/kubernetes/pkg/client/listers/core/v1"
 	"k8s.io/kubernetes/pkg/genericapiserver"
 	genericfilters "k8s.io/kubernetes/pkg/genericapiserver/filters"
 	"k8s.io/kubernetes/pkg/registry/generic"
@@ -33,7 +36,7 @@ import (
 
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/apis/apiregistration"
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/apis/apiregistration/v1alpha1"
-	clientset "k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/client/clientset_generated/clientset"
+	discoveryclientset "k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/client/clientset_generated/clientset"
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/client/informers"
 	listers "k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/client/listers/apiregistration/internalversion"
@@ -44,7 +47,8 @@ import (
 const legacyAPIServiceName = "v1."
 
 type Config struct {
-	GenericConfig *genericapiserver.Config
+	GenericConfig       *genericapiserver.Config
+	CoreAPIServerClient kubeclientset.Interface
 
 	// ProxyClientCert/Key are the client cert used to identify this proxy. Backing APIServices use
 	// this to confirm the proxy's identity
@@ -73,6 +77,11 @@ type APIDiscoveryServer struct {
 	// controller state
 	lister listers.APIServiceLister
 
+	// serviceLister is used by the discovery handler to determine whether or not to try to expose the group
+	serviceLister v1listers.ServiceLister
+	// endpointsLister is used by the discovery handler to determine whether or not to try to expose the group
+	endpointsLister v1listers.EndpointsLister
+
 	// proxyMux intercepts requests that need to be proxied to backing API servers
 	proxyMux *http.ServeMux
 }
@@ -100,16 +109,19 @@ func (c *Config) SkipComplete() completedConfig {
 func (c completedConfig) New() (*APIDiscoveryServer, error) {
 	informerFactory := informers.NewSharedInformerFactory(
 		internalclientset.NewForConfigOrDie(c.Config.GenericConfig.LoopbackClientConfig),
-		clientset.NewForConfigOrDie(c.Config.GenericConfig.LoopbackClientConfig),
+		discoveryclientset.NewForConfigOrDie(c.Config.GenericConfig.LoopbackClientConfig),
 		5*time.Minute, // this is effectively used as a refresh interval right now.  Might want to do something nicer later on.
 	)
+	kubeInformers := kubeinformers.NewSharedInformerFactory(nil, c.CoreAPIServerClient, 5*time.Minute)
 
 	proxyMux := http.NewServeMux()
 
 	// most API servers don't need to do this, but we need a custom handler chain to handle the special /apis handling here
 	c.Config.GenericConfig.BuildHandlerChainsFunc = (&handlerChainConfig{
-		informers: informerFactory,
-		proxyMux:  proxyMux,
+		informers:       informerFactory,
+		proxyMux:        proxyMux,
+		serviceLister:   kubeInformers.Core().V1().Services().Lister(),
+		endpointsLister: kubeInformers.Core().V1().Endpoints().Lister(),
 	}).handlerChain
 
 	genericServer, err := c.Config.GenericConfig.SkipComplete().New() // completion is done in Complete, no need for a second time
@@ -124,6 +136,8 @@ func (c completedConfig) New() (*APIDiscoveryServer, error) {
 		proxyClientKey:   c.ProxyClientKey,
 		proxyHandlers:    map[string]*proxyHandler{},
 		lister:           informerFactory.Apiregistration().InternalVersion().APIServices().Lister(),
+		serviceLister:    kubeInformers.Core().V1().Services().Lister(),
+		endpointsLister:  kubeInformers.Core().V1().Endpoints().Lister(),
 		proxyMux:         proxyMux,
 	}
 
@@ -141,6 +155,7 @@ func (c completedConfig) New() (*APIDiscoveryServer, error) {
 
 	s.GenericAPIServer.AddPostStartHook("start-informers", func(context genericapiserver.PostStartHookContext) error {
 		informerFactory.Start(wait.NeverStop)
+		kubeInformers.Start(wait.NeverStop)
 		return nil
 	})
 	s.GenericAPIServer.AddPostStartHook("apiservice-registration-controller", func(context genericapiserver.PostStartHookContext) error {
@@ -153,8 +168,10 @@ func (c completedConfig) New() (*APIDiscoveryServer, error) {
 
 // handlerChainConfig is the config used to build the custom handler chain for this api server
 type handlerChainConfig struct {
-	informers informers.SharedInformerFactory
-	proxyMux  *http.ServeMux
+	informers       informers.SharedInformerFactory
+	proxyMux        *http.ServeMux
+	serviceLister   v1listers.ServiceLister
+	endpointsLister v1listers.EndpointsLister
 }
 
 // handlerChain is a method to build the handler chain for this API server.  We need a custom handler chain so that we
@@ -162,7 +179,7 @@ type handlerChainConfig struct {
 // the endpoints differently, since we're proxying all groups except for apiregistration.k8s.io.
 func (h *handlerChainConfig) handlerChain(apiHandler http.Handler, c *genericapiserver.Config) (secure, insecure http.Handler) {
 	// add this as a filter so that we never collide with "already registered" failures on `/apis`
-	handler := WithAPIs(apiHandler, h.informers.Apiregistration().InternalVersion().APIServices())
+	handler := WithAPIs(apiHandler, h.informers.Apiregistration().InternalVersion().APIServices(), h.serviceLister, h.endpointsLister)
 
 	handler = apiserverfilters.WithAuthorization(handler, c.RequestContextMapper, c.Authorizer)
 
@@ -223,8 +240,10 @@ func (s *APIDiscoveryServer) AddAPIService(apiService *apiregistration.APIServic
 	// it's time to register the group discovery endpoint
 	groupPath := "/apis/" + apiService.Spec.Group
 	groupDiscoveryHandler := &apiGroupHandler{
-		groupName: apiService.Spec.Group,
-		lister:    s.lister,
+		groupName:       apiService.Spec.Group,
+		lister:          s.lister,
+		serviceLister:   s.serviceLister,
+		endpointsLister: s.endpointsLister,
 	}
 	// discovery is protected
 	s.GenericAPIServer.HandlerContainer.UnlistedRoutes.Handle(groupPath, groupDiscoveryHandler)

cmd/kubernetes-discovery/pkg/apiserver/handler_apis.go

@@ -24,6 +24,7 @@ import (
 	apierrors "k8s.io/kubernetes/pkg/api/errors"
 	metav1 "k8s.io/kubernetes/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/pkg/apiserver"
+	v1listers "k8s.io/kubernetes/pkg/client/listers/core/v1"
 	"k8s.io/kubernetes/pkg/labels"
 	"k8s.io/kubernetes/pkg/runtime"
 
@@ -34,10 +35,12 @@ import (
 )
 
 // WithAPIs adds the handling for /apis and /apis/<group: -apiregistration.k8s.io>.
-func WithAPIs(handler http.Handler, informer informers.APIServiceInformer) http.Handler {
+func WithAPIs(handler http.Handler, informer informers.APIServiceInformer, serviceLister v1listers.ServiceLister, endpointsLister v1listers.EndpointsLister) http.Handler {
 	apisHandler := &apisHandler{
-		lister:   informer.Lister(),
-		delegate: handler,
+		lister:          informer.Lister(),
+		delegate:        handler,
+		serviceLister:   serviceLister,
+		endpointsLister: endpointsLister,
 	}
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		apisHandler.ServeHTTP(w, req)
@@ -49,6 +52,9 @@ func WithAPIs(handler http.Handler, informer informers.APIServiceInformer) http.
 type apisHandler struct {
 	lister listers.APIServiceLister
 
+	serviceLister   v1listers.ServiceLister
+	endpointsLister v1listers.EndpointsLister
+
 	delegate http.Handler
 }
 
@@ -95,7 +101,10 @@ func (r *apisHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		if len(apiGroupServers[0].Spec.Group) == 0 {
 			continue
 		}
-		discoveryGroupList.Groups = append(discoveryGroupList.Groups, *newDiscoveryAPIGroup(apiGroupServers))
+		discoveryGroup := convertToDiscoveryAPIGroup(apiGroupServers, r.serviceLister, r.endpointsLister)
+		if discoveryGroup != nil {
+			discoveryGroupList.Groups = append(discoveryGroupList.Groups, *discoveryGroup)
+		}
 	}
 
 	json, err := runtime.Encode(api.Codecs.LegacyCodec(), discoveryGroupList)
@@ -108,18 +117,46 @@ func (r *apisHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 }
 
-func newDiscoveryAPIGroup(apiServices []*apiregistrationapi.APIService) *metav1.APIGroup {
+// convertToDiscoveryAPIGroup takes apiservices in a single group and returns a discovery compatible object.
+// if none of the services are available, it will return nil.
+func convertToDiscoveryAPIGroup(apiServices []*apiregistrationapi.APIService, serviceLister v1listers.ServiceLister, endpointsLister v1listers.EndpointsLister) *metav1.APIGroup {
 	apiServicesByGroup := apiregistrationapi.SortedByGroup(apiServices)[0]
 
-	discoveryGroup := &metav1.APIGroup{
-		Name: apiServicesByGroup[0].Spec.Group,
-		PreferredVersion: metav1.GroupVersionForDiscovery{
-			GroupVersion: apiServicesByGroup[0].Spec.Group + "/" + apiServicesByGroup[0].Spec.Version,
-			Version:      apiServicesByGroup[0].Spec.Version,
-		},
-	}
+	var discoveryGroup *metav1.APIGroup
 
 	for _, apiService := range apiServicesByGroup {
+		// skip any API services without actual services
+		if _, err := serviceLister.Services(apiService.Spec.Service.Namespace).Get(apiService.Spec.Service.Name); err != nil {
+			continue
+		}
+
+		hasActiveEndpoints := false
+		endpoints, err := endpointsLister.Endpoints(apiService.Spec.Service.Namespace).Get(apiService.Spec.Service.Name)
+		// skip any API services without endpoints
+		if err != nil {
+			continue
+		}
+		for _, subset := range endpoints.Subsets {
+			if len(subset.Addresses) > 0 {
+				hasActiveEndpoints = true
+				break
+			}
+		}
+		if !hasActiveEndpoints {
+			continue
+		}
+
+		// the first APIService which is valid becomes the default
+		if discoveryGroup == nil {
+			discoveryGroup = &metav1.APIGroup{
+				Name: apiService.Spec.Group,
+				PreferredVersion: metav1.GroupVersionForDiscovery{
+					GroupVersion: apiService.Spec.Group + "/" + apiService.Spec.Version,
+					Version:      apiService.Spec.Version,
+				},
+			}
+		}
+
 		discoveryGroup.Versions = append(discoveryGroup.Versions,
 			metav1.GroupVersionForDiscovery{
 				GroupVersion: apiService.Spec.Group + "/" + apiService.Spec.Version,
@@ -136,6 +173,9 @@ type apiGroupHandler struct {
 	groupName string
 
 	lister listers.APIServiceLister
+
+	serviceLister   v1listers.ServiceLister
+	endpointsLister v1listers.EndpointsLister
 }
 
 func (r *apiGroupHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
@@ -167,7 +207,12 @@ func (r *apiGroupHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	json, err := runtime.Encode(api.Codecs.LegacyCodec(), newDiscoveryAPIGroup(apiServicesForGroup))
+	discoveryGroup := convertToDiscoveryAPIGroup(apiServicesForGroup, r.serviceLister, r.endpointsLister)
+	if discoveryGroup == nil {
+		http.Error(w, "", http.StatusNotFound)
+		return
+	}
+	json, err := runtime.Encode(api.Codecs.LegacyCodec(), discoveryGroup)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return

cmd/kubernetes-discovery/pkg/apiserver/handler_apis_test.go

@@ -24,8 +24,10 @@ import (
 	"testing"
 
 	"k8s.io/kubernetes/pkg/api"
+	corev1 "k8s.io/kubernetes/pkg/api/v1"
 	metav1 "k8s.io/kubernetes/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/pkg/client/cache"
+	v1listers "k8s.io/kubernetes/pkg/client/listers/core/v1"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util/diff"
 
@@ -111,6 +113,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.foo"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "foo",
 						Version:  "v1",
 						Priority: 10,
@@ -119,6 +125,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.bar"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "bar",
 						Version:  "v1",
 						Priority: 11,
@@ -164,6 +174,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.foo"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "foo",
 						Version:  "v1",
 						Priority: 20,
@@ -172,6 +186,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v2.bar"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "bar",
 						Version:  "v2",
 						Priority: 11,
@@ -180,6 +198,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v2.foo"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "foo",
 						Version:  "v2",
 						Priority: 1,
@@ -188,6 +210,10 @@ func TestAPIs(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.bar"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "bar",
 						Version:  "v1",
 						Priority: 11,
@@ -239,14 +265,26 @@ func TestAPIs(t *testing.T) {
 
 	for _, tc := range tests {
 		indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+		serviceIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+		endpointsIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
 		delegate := &delegationHTTPHandler{}
 		handler := &apisHandler{
-			lister:   listers.NewAPIServiceLister(indexer),
-			delegate: delegate,
+			serviceLister:   v1listers.NewServiceLister(serviceIndexer),
+			endpointsLister: v1listers.NewEndpointsLister(endpointsIndexer),
+			lister:          listers.NewAPIServiceLister(indexer),
+			delegate:        delegate,
 		}
 		for _, o := range tc.apiservices {
 			indexer.Add(o)
 		}
+		serviceIndexer.Add(&corev1.Service{ObjectMeta: corev1.ObjectMeta{Namespace: "ns", Name: "api"}})
+		endpointsIndexer.Add(&corev1.Endpoints{
+			ObjectMeta: corev1.ObjectMeta{Namespace: "ns", Name: "api"},
+			Subsets: []corev1.EndpointSubset{
+				{Addresses: []corev1.EndpointAddress{{}}},
+			},
+		},
+		)
 
 		server := httptest.NewServer(handler)
 		defer server.Close()
@@ -316,6 +354,10 @@ func TestAPIGroup(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.foo"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "foo",
 						Version:  "v1",
 						Priority: 20,
@@ -324,6 +366,10 @@ func TestAPIGroup(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v2.bar"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "bar",
 						Version:  "v2",
 						Priority: 11,
@@ -332,6 +378,10 @@ func TestAPIGroup(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v2.foo"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "foo",
 						Version:  "v2",
 						Priority: 1,
@@ -340,6 +390,10 @@ func TestAPIGroup(t *testing.T) {
 				{
 					ObjectMeta: api.ObjectMeta{Name: "v1.bar"},
 					Spec: apiregistration.APIServiceSpec{
+						Service: apiregistration.ServiceReference{
+							Namespace: "ns",
+							Name:      "api",
+						},
 						Group:    "bar",
 						Version:  "v1",
 						Priority: 11,
@@ -369,13 +423,25 @@ func TestAPIGroup(t *testing.T) {
 
 	for _, tc := range tests {
 		indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+		serviceIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+		endpointsIndexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
 		handler := &apiGroupHandler{
-			lister:    listers.NewAPIServiceLister(indexer),
-			groupName: "foo",
+			lister:          listers.NewAPIServiceLister(indexer),
+			serviceLister:   v1listers.NewServiceLister(serviceIndexer),
+			endpointsLister: v1listers.NewEndpointsLister(endpointsIndexer),
+			groupName:       "foo",
 		}
 		for _, o := range tc.apiservices {
 			indexer.Add(o)
 		}
+		serviceIndexer.Add(&corev1.Service{ObjectMeta: corev1.ObjectMeta{Namespace: "ns", Name: "api"}})
+		endpointsIndexer.Add(&corev1.Endpoints{
+			ObjectMeta: corev1.ObjectMeta{Namespace: "ns", Name: "api"},
+			Subsets: []corev1.EndpointSubset{
+				{Addresses: []corev1.EndpointAddress{{}}},
+			},
+		},
+		)
 
 		server := httptest.NewServer(handler)
 		defer server.Close()
@@ -386,8 +452,8 @@ func TestAPIGroup(t *testing.T) {
 			continue
 		}
 		if resp.StatusCode != http.StatusOK {
-			httputil.DumpResponse(resp, true)
-			t.Errorf("%s", tc.name)
+			response, _ := httputil.DumpResponse(resp, true)
+			t.Errorf("%s: %v", tc.name, string(response))
 			continue
 		}
 		bytes, err := ioutil.ReadAll(resp.Body)

cmd/kubernetes-discovery/pkg/cmd/server/BUILD

@@ -16,6 +16,8 @@ go_library(
         "//cmd/kubernetes-discovery/pkg/apiserver:go_default_library",
         "//cmd/kubernetes-discovery/pkg/legacy:go_default_library",
         "//pkg/api:go_default_library",
+        "//pkg/client/clientset_generated/clientset:go_default_library",
+        "//pkg/client/restclient:go_default_library",
         "//pkg/genericapiserver:go_default_library",
         "//pkg/genericapiserver/filters:go_default_library",
         "//pkg/genericapiserver/options:go_default_library",

cmd/kubernetes-discovery/pkg/cmd/server/start.go

@@ -27,6 +27,8 @@ import (
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/apiserver"
 	"k8s.io/kubernetes/cmd/kubernetes-discovery/pkg/legacy"
 	"k8s.io/kubernetes/pkg/api"
+	kubeclientset "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
+	"k8s.io/kubernetes/pkg/client/restclient"
 	"k8s.io/kubernetes/pkg/genericapiserver"
 	"k8s.io/kubernetes/pkg/genericapiserver/filters"
 	genericoptions "k8s.io/kubernetes/pkg/genericapiserver/options"
@@ -135,9 +137,19 @@ func (o DiscoveryServerOptions) RunDiscoveryServer() error {
 		return err
 	}
 
+	kubeconfig, err := restclient.InClusterConfig()
+	if err != nil {
+		return err
+	}
+	coreAPIServerClient, err := kubeclientset.NewForConfig(kubeconfig)
+	if err != nil {
+		return err
+	}
+
 	config := apiserver.Config{
-		GenericConfig:     genericAPIServerConfig,
-		RESTOptionsGetter: &restOptionsFactory{storageConfig: &o.Etcd.StorageConfig},
+		GenericConfig:       genericAPIServerConfig,
+		RESTOptionsGetter:   &restOptionsFactory{storageConfig: &o.Etcd.StorageConfig},
+		CoreAPIServerClient: coreAPIServerClient,
 	}
 
 	config.ProxyClientCert, err = ioutil.ReadFile(o.ProxyClientCertFile)

hack/local-up-discovery.sh

@@ -59,7 +59,9 @@ function start_discovery {
 
 	# grant permission to run delegated authentication and authorization checks
 	kubectl_core delete clusterrolebinding discovery:system:auth-delegator > /dev/null 2>&1 || true
+	kubectl_core delete clusterrolebinding discovery:system:kubernetes-discovery > /dev/null 2>&1 || true
 	kubectl_core create clusterrolebinding discovery:system:auth-delegator --clusterrole=system:auth-delegator --serviceaccount=kube-public:kubernetes-discovery
+	kubectl_core create clusterrolebinding discovery:system:kubernetes-discovery --clusterrole=system:kubernetes-discovery --serviceaccount=kube-public:kubernetes-discovery
 
 	# make sure the resources we're about to create don't exist
 	kubectl_core -n kube-public delete secret auth-proxy-client serving-etcd serving-discovery discovery-etcd > /dev/null 2>&1 || true

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/policy.go

@@ -231,6 +231,14 @@ func ClusterRoles() []rbac.ClusterRole {
 			},
 		},
 		{
+			// a role to use for the API registry, summarization, and proxy handling
+			ObjectMeta: api.ObjectMeta{Name: "system:kubernetes-discovery"},
+			Rules: []rbac.PolicyRule{
+				// it needs to see all services so that it knows whether the ones it points to exist or not
+				rbac.NewRule(Read...).Groups(legacyGroup).Resources("services", "endpoints").RuleOrDie(),
+			},
+		},
+		{
 			// a role to use for bootstrapping the kube-controller-manager so it can create the shared informers
 			// service accounts, and secrets that we need to create separate identities for other controllers
 			ObjectMeta: api.ObjectMeta{Name: "system:kube-controller-manager"},

plugin/pkg/auth/authorizer/rbac/bootstrappolicy/testdata/cluster-roles.yaml

@@ -475,6 +475,24 @@ items:
     creationTimestamp: null
     labels:
       kubernetes.io/bootstrapping: rbac-defaults
+    name: system:kubernetes-discovery
+  rules:
+  - apiGroups:
+    - ""
+    attributeRestrictions: null
+    resources:
+    - endpoints
+    - services
+    verbs:
+    - get
+    - list
+    - watch
+- apiVersion: rbac.authorization.k8s.io/v1alpha1
+  kind: ClusterRole
+  metadata:
+    creationTimestamp: null
+    labels:
+      kubernetes.io/bootstrapping: rbac-defaults
     name: system:node
   rules:
   - apiGroups: