git subrepo clone (merge) https://github.com/kubernetes-incubator/metrics-server.git metrics-server

subrepo:
  subdir:   "metrics-server"
  merged:   "92d8412"
upstream:
  origin:   "https://github.com/kubernetes-incubator/metrics-server.git"
  branch:   "master"
  commit:   "92d8412"
git-subrepo:
  version:  "0.4.0"
  origin:   "???"
  commit:   "???"
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/authentication/group/authenticated_group_adder.go b/metrics-server/vendor/k8s.io/apiserver/pkg/authentication/group/authenticated_group_adder.go
new file mode 100644
index 0000000..9f0453b
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/authentication/group/authenticated_group_adder.go
@@ -0,0 +1,60 @@
+/*
+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 group
+
+import (
+	"net/http"
+
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/authentication/user"
+)
+
+// AuthenticatedGroupAdder adds system:authenticated group when appropriate
+type AuthenticatedGroupAdder struct {
+	// Authenticator is delegated to make the authentication decision
+	Authenticator authenticator.Request
+}
+
+// NewAuthenticatedGroupAdder wraps a request authenticator, and adds the system:authenticated group when appropriate.
+// Authentication must succeed, the user must not be system:anonymous, the groups system:authenticated or system:unauthenticated must
+// not be present
+func NewAuthenticatedGroupAdder(auth authenticator.Request) authenticator.Request {
+	return &AuthenticatedGroupAdder{auth}
+}
+
+func (g *AuthenticatedGroupAdder) AuthenticateRequest(req *http.Request) (user.Info, bool, error) {
+	u, ok, err := g.Authenticator.AuthenticateRequest(req)
+	if err != nil || !ok {
+		return nil, ok, err
+	}
+
+	if u.GetName() == user.Anonymous {
+		return u, true, nil
+	}
+	for _, group := range u.GetGroups() {
+		if group == user.AllAuthenticated || group == user.AllUnauthenticated {
+			return u, true, nil
+		}
+	}
+
+	return &user.DefaultInfo{
+		Name:   u.GetName(),
+		UID:    u.GetUID(),
+		Groups: append(u.GetGroups(), user.AllAuthenticated),
+		Extra:  u.GetExtra(),
+	}, true, nil
+}