diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/discovery/group.go b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/discovery/group.go
new file mode 100644
index 0000000..02330e9
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/endpoints/discovery/group.go
@@ -0,0 +1,73 @@
+/*
+Copyright 2017 The Kubernetes 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 discovery
+
+import (
+	"net/http"
+
+	"github.com/emicklei/go-restful"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
+	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
+)
+
+// APIGroupHandler creates a webservice serving the supported versions, preferred version, and name
+// of a group. E.g., such a web service will be registered at /apis/extensions.
+type APIGroupHandler struct {
+	serializer runtime.NegotiatedSerializer
+	group      metav1.APIGroup
+}
+
+func NewAPIGroupHandler(serializer runtime.NegotiatedSerializer, group metav1.APIGroup) *APIGroupHandler {
+	if keepUnversioned(group.Name) {
+		// Because in release 1.1, /apis/extensions returns response with empty
+		// APIVersion, we use stripVersionNegotiatedSerializer to keep the
+		// response backwards compatible.
+		serializer = stripVersionNegotiatedSerializer{serializer}
+	}
+
+	return &APIGroupHandler{
+		serializer: serializer,
+		group:      group,
+	}
+}
+
+func (s *APIGroupHandler) WebService() *restful.WebService {
+	mediaTypes, _ := negotiation.MediaTypesForSerializer(s.serializer)
+	ws := new(restful.WebService)
+	ws.Path(APIGroupPrefix + "/" + s.group.Name)
+	ws.Doc("get information of a group")
+	ws.Route(ws.GET("/").To(s.handle).
+		Doc("get information of a group").
+		Operation("getAPIGroup").
+		Produces(mediaTypes...).
+		Consumes(mediaTypes...).
+		Writes(metav1.APIGroup{}))
+	return ws
+}
+
+// handle returns a handler which will return the api.GroupAndVersion of the group.
+func (s *APIGroupHandler) handle(req *restful.Request, resp *restful.Response) {
+	s.ServeHTTP(resp.ResponseWriter, req.Request)
+}
+
+func (s *APIGroupHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	responsewriters.WriteObjectNegotiated(s.serializer, schema.GroupVersion{}, w, req, http.StatusOK, &s.group)
+}