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/client-go/discovery/helper.go b/metrics-server/vendor/k8s.io/client-go/discovery/helper.go
new file mode 100644
index 0000000..353d34b
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/client-go/discovery/helper.go
@@ -0,0 +1,121 @@
+/*
+Copyright 2016 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 (
+	"fmt"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/sets"
+	apimachineryversion "k8s.io/apimachinery/pkg/version"
+)
+
+// MatchesServerVersion queries the server to compares the build version
+// (git hash) of the client with the server's build version. It returns an error
+// if it failed to contact the server or if the versions are not an exact match.
+func MatchesServerVersion(clientVersion apimachineryversion.Info, client DiscoveryInterface) error {
+	sVer, err := client.ServerVersion()
+	if err != nil {
+		return fmt.Errorf("couldn't read version from server: %v\n", err)
+	}
+	// GitVersion includes GitCommit and GitTreeState, but best to be safe?
+	if clientVersion.GitVersion != sVer.GitVersion || clientVersion.GitCommit != sVer.GitCommit || clientVersion.GitTreeState != sVer.GitTreeState {
+		return fmt.Errorf("server version (%#v) differs from client version (%#v)!\n", sVer, clientVersion)
+	}
+
+	return nil
+}
+
+// ServerSupportsVersion returns an error if the server doesn't have the required version
+func ServerSupportsVersion(client DiscoveryInterface, requiredGV schema.GroupVersion) error {
+	groups, err := client.ServerGroups()
+	if err != nil {
+		// This is almost always a connection error, and higher level code should treat this as a generic error,
+		// not a negotiation specific error.
+		return err
+	}
+	versions := metav1.ExtractGroupVersions(groups)
+	serverVersions := sets.String{}
+	for _, v := range versions {
+		serverVersions.Insert(v)
+	}
+
+	if serverVersions.Has(requiredGV.String()) {
+		return nil
+	}
+
+	// If the server supports no versions, then we should pretend it has the version because of old servers.
+	// This can happen because discovery fails due to 403 Forbidden errors
+	if len(serverVersions) == 0 {
+		return nil
+	}
+
+	return fmt.Errorf("server does not support API version %q", requiredGV)
+}
+
+// GroupVersionResources converts APIResourceLists to the GroupVersionResources.
+func GroupVersionResources(rls []*metav1.APIResourceList) (map[schema.GroupVersionResource]struct{}, error) {
+	gvrs := map[schema.GroupVersionResource]struct{}{}
+	for _, rl := range rls {
+		gv, err := schema.ParseGroupVersion(rl.GroupVersion)
+		if err != nil {
+			return nil, err
+		}
+		for i := range rl.APIResources {
+			gvrs[schema.GroupVersionResource{Group: gv.Group, Version: gv.Version, Resource: rl.APIResources[i].Name}] = struct{}{}
+		}
+	}
+	return gvrs, nil
+}
+
+// FilteredBy filters by the given predicate. Empty APIResourceLists are dropped.
+func FilteredBy(pred ResourcePredicate, rls []*metav1.APIResourceList) []*metav1.APIResourceList {
+	result := []*metav1.APIResourceList{}
+	for _, rl := range rls {
+		filtered := *rl
+		filtered.APIResources = nil
+		for i := range rl.APIResources {
+			if pred.Match(rl.GroupVersion, &rl.APIResources[i]) {
+				filtered.APIResources = append(filtered.APIResources, rl.APIResources[i])
+			}
+		}
+		if filtered.APIResources != nil {
+			result = append(result, &filtered)
+		}
+	}
+	return result
+}
+
+type ResourcePredicate interface {
+	Match(groupVersion string, r *metav1.APIResource) bool
+}
+
+type ResourcePredicateFunc func(groupVersion string, r *metav1.APIResource) bool
+
+func (fn ResourcePredicateFunc) Match(groupVersion string, r *metav1.APIResource) bool {
+	return fn(groupVersion, r)
+}
+
+// SupportsAllVerbs is a predicate matching a resource iff all given verbs are supported.
+type SupportsAllVerbs struct {
+	Verbs []string
+}
+
+func (p SupportsAllVerbs) Match(groupVersion string, r *metav1.APIResource) bool {
+	return sets.NewString([]string(r.Verbs)...).HasAll(p.Verbs...)
+}