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/registry/generic/OWNERS b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/OWNERS
new file mode 100755
index 0000000..75e1393
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/OWNERS
@@ -0,0 +1,34 @@
+reviewers:
+- thockin
+- lavalamp
+- smarterclayton
+- wojtek-t
+- deads2k
+- yujuhong
+- derekwaynecarr
+- caesarxuchao
+- mikedanese
+- liggitt
+- nikhiljindal
+- gmarek
+- davidopp
+- saad-ali
+- janetkuo
+- pwittrock
+- roberthbailey
+- ncdc
+- eparis
+- jlowdermilk
+- piosz
+- dims
+- hongchaodeng
+- krousey
+- markturansky
+- fgrzadkowski
+- xiang90
+- resouer
+- mqliang
+- feihujiang
+- sdminonne
+- goltermann
+- enj
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/doc.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/doc.go
new file mode 100644
index 0000000..ea79d13
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/doc.go
@@ -0,0 +1,19 @@
+/*
+Copyright 2014 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 generic provides a generic object store interface and a
+// generic label/field matching type.
+package generic // import "k8s.io/apiserver/pkg/registry/generic"
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/matcher.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/matcher.go
new file mode 100644
index 0000000..4364374
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/matcher.go
@@ -0,0 +1,52 @@
+/*
+Copyright 2014 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 generic
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+)
+
+// ObjectMetaFieldsSet returns a fields that represent the ObjectMeta.
+func ObjectMetaFieldsSet(objectMeta *metav1.ObjectMeta, hasNamespaceField bool) fields.Set {
+	if !hasNamespaceField {
+		return fields.Set{
+			"metadata.name": objectMeta.Name,
+		}
+	}
+	return fields.Set{
+		"metadata.name":      objectMeta.Name,
+		"metadata.namespace": objectMeta.Namespace,
+	}
+}
+
+// AdObjectMetaField add fields that represent the ObjectMeta to source.
+func AddObjectMetaFieldsSet(source fields.Set, objectMeta *metav1.ObjectMeta, hasNamespaceField bool) fields.Set {
+	source["metadata.name"] = objectMeta.Name
+	if hasNamespaceField {
+		source["metadata.namespace"] = objectMeta.Namespace
+	}
+	return source
+}
+
+// MergeFieldsSets merges a fields'set from fragment into the source.
+func MergeFieldsSets(source fields.Set, fragment fields.Set) fields.Set {
+	for k, value := range fragment {
+		source[k] = value
+	}
+	return source
+}
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/options.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/options.go
new file mode 100644
index 0000000..af65137
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/options.go
@@ -0,0 +1,52 @@
+/*
+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 generic
+
+import (
+	"time"
+
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apiserver/pkg/storage"
+	"k8s.io/apiserver/pkg/storage/storagebackend"
+)
+
+// RESTOptions is set of configuration options to generic registries.
+type RESTOptions struct {
+	StorageConfig *storagebackend.Config
+	Decorator     StorageDecorator
+
+	EnableGarbageCollection bool
+	DeleteCollectionWorkers int
+	ResourcePrefix          string
+	CountMetricPollPeriod   time.Duration
+}
+
+// Implement RESTOptionsGetter so that RESTOptions can directly be used when available (i.e. tests)
+func (opts RESTOptions) GetRESTOptions(schema.GroupResource) (RESTOptions, error) {
+	return opts, nil
+}
+
+type RESTOptionsGetter interface {
+	GetRESTOptions(resource schema.GroupResource) (RESTOptions, error)
+}
+
+// StoreOptions is set of configuration options used to complete generic registries.
+type StoreOptions struct {
+	RESTOptions RESTOptionsGetter
+	TriggerFunc storage.TriggerPublisherFunc
+	AttrFunc    storage.AttrFunc
+}
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/decorated_watcher.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/decorated_watcher.go
new file mode 100644
index 0000000..f589dd1
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/decorated_watcher.go
@@ -0,0 +1,96 @@
+/*
+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 registry
+
+import (
+	"context"
+	"net/http"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
+)
+
+type decoratedWatcher struct {
+	w         watch.Interface
+	decorator ObjectFunc
+	cancel    context.CancelFunc
+	resultCh  chan watch.Event
+}
+
+func newDecoratedWatcher(w watch.Interface, decorator ObjectFunc) *decoratedWatcher {
+	ctx, cancel := context.WithCancel(context.Background())
+	d := &decoratedWatcher{
+		w:         w,
+		decorator: decorator,
+		cancel:    cancel,
+		resultCh:  make(chan watch.Event),
+	}
+	go d.run(ctx)
+	return d
+}
+
+func (d *decoratedWatcher) run(ctx context.Context) {
+	var recv, send watch.Event
+	for {
+		select {
+		case recv = <-d.w.ResultChan():
+			switch recv.Type {
+			case watch.Added, watch.Modified, watch.Deleted:
+				err := d.decorator(recv.Object)
+				if err != nil {
+					send = makeStatusErrorEvent(err)
+					break
+				}
+				send = recv
+			case watch.Error:
+				send = recv
+			}
+			select {
+			case d.resultCh <- send:
+				if send.Type == watch.Error {
+					d.cancel()
+				}
+			case <-ctx.Done():
+			}
+		case <-ctx.Done():
+			d.w.Stop()
+			close(d.resultCh)
+			return
+		}
+	}
+}
+
+func (d *decoratedWatcher) Stop() {
+	d.cancel()
+}
+
+func (d *decoratedWatcher) ResultChan() <-chan watch.Event {
+	return d.resultCh
+}
+
+func makeStatusErrorEvent(err error) watch.Event {
+	status := &metav1.Status{
+		Status:  metav1.StatusFailure,
+		Message: err.Error(),
+		Code:    http.StatusInternalServerError,
+		Reason:  metav1.StatusReasonInternalError,
+	}
+	return watch.Event{
+		Type:   watch.Error,
+		Object: status,
+	}
+}
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/doc.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/doc.go
new file mode 100644
index 0000000..bd315ae
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/doc.go
@@ -0,0 +1,19 @@
+/*
+Copyright 2014 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 etcd has a generic implementation of a registry that
+// stores things in etcd.
+package registry // import "k8s.io/apiserver/pkg/registry/generic/registry"
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/storage_factory.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/storage_factory.go
new file mode 100644
index 0000000..c1ef906
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/storage_factory.go
@@ -0,0 +1,119 @@
+/*
+Copyright 2015 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 registry
+
+import (
+	"sync"
+
+	"github.com/golang/glog"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apiserver/pkg/registry/generic"
+	"k8s.io/apiserver/pkg/storage"
+	etcdstorage "k8s.io/apiserver/pkg/storage/etcd"
+	"k8s.io/apiserver/pkg/storage/storagebackend"
+	"k8s.io/apiserver/pkg/storage/storagebackend/factory"
+)
+
+// Creates a cacher based given storageConfig.
+func StorageWithCacher(capacity int) generic.StorageDecorator {
+	return func(
+		storageConfig *storagebackend.Config,
+		objectType runtime.Object,
+		resourcePrefix string,
+		keyFunc func(obj runtime.Object) (string, error),
+		newListFunc func() runtime.Object,
+		getAttrsFunc storage.AttrFunc,
+		triggerFunc storage.TriggerPublisherFunc) (storage.Interface, factory.DestroyFunc) {
+
+		s, d := generic.NewRawStorage(storageConfig)
+		if capacity == 0 {
+			glog.V(5).Infof("Storage caching is disabled for %T", objectType)
+			return s, d
+		}
+		glog.V(5).Infof("Storage caching is enabled for %T with capacity %v", objectType, capacity)
+
+		// TODO: we would change this later to make storage always have cacher and hide low level KV layer inside.
+		// Currently it has two layers of same storage interface -- cacher and low level kv.
+		cacherConfig := storage.CacherConfig{
+			CacheCapacity:        capacity,
+			Storage:              s,
+			Versioner:            etcdstorage.APIObjectVersioner{},
+			Type:                 objectType,
+			ResourcePrefix:       resourcePrefix,
+			KeyFunc:              keyFunc,
+			NewListFunc:          newListFunc,
+			GetAttrsFunc:         getAttrsFunc,
+			TriggerPublisherFunc: triggerFunc,
+			Codec:                storageConfig.Codec,
+		}
+		cacher := storage.NewCacherFromConfig(cacherConfig)
+		destroyFunc := func() {
+			cacher.Stop()
+			d()
+		}
+
+		// TODO : Remove RegisterStorageCleanup below when PR
+		// https://github.com/kubernetes/kubernetes/pull/50690
+		// merges as that shuts down storage properly
+		RegisterStorageCleanup(destroyFunc)
+
+		return cacher, destroyFunc
+	}
+}
+
+// TODO : Remove all the code below when PR
+// https://github.com/kubernetes/kubernetes/pull/50690
+// merges as that shuts down storage properly
+// HACK ALERT : Track the destroy methods to call them
+// from the test harness. TrackStorageCleanup will be called
+// only from the test harness, so Register/Cleanup will be
+// no-op at runtime.
+
+var cleanupLock sync.Mutex
+var cleanup []func() = nil
+
+func TrackStorageCleanup() {
+	cleanupLock.Lock()
+	defer cleanupLock.Unlock()
+
+	if cleanup != nil {
+		panic("Conflicting storage tracking")
+	}
+	cleanup = make([]func(), 0)
+}
+
+func RegisterStorageCleanup(fn func()) {
+	cleanupLock.Lock()
+	defer cleanupLock.Unlock()
+
+	if cleanup == nil {
+		return
+	}
+	cleanup = append(cleanup, fn)
+}
+
+func CleanupStorage() {
+	cleanupLock.Lock()
+	old := cleanup
+	cleanup = nil
+	cleanupLock.Unlock()
+
+	for _, d := range old {
+		d()
+	}
+}
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/store.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/store.go
new file mode 100644
index 0000000..1e799c6
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/registry/store.go
@@ -0,0 +1,1416 @@
+/*
+Copyright 2014 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 registry
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"time"
+
+	kubeerr "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/api/validation/path"
+	metainternalversion "k8s.io/apimachinery/pkg/apis/meta/internalversion"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	metav1beta1 "k8s.io/apimachinery/pkg/apis/meta/v1beta1"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/apimachinery/pkg/watch"
+	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
+	"k8s.io/apiserver/pkg/registry/generic"
+	"k8s.io/apiserver/pkg/registry/rest"
+	"k8s.io/apiserver/pkg/storage"
+	storeerr "k8s.io/apiserver/pkg/storage/errors"
+	"k8s.io/apiserver/pkg/storage/etcd/metrics"
+
+	"github.com/golang/glog"
+)
+
+// ObjectFunc is a function to act on a given object. An error may be returned
+// if the hook cannot be completed. An ObjectFunc may transform the provided
+// object.
+type ObjectFunc func(obj runtime.Object) error
+
+// GenericStore interface can be used for type assertions when we need to access the underlying strategies.
+type GenericStore interface {
+	GetCreateStrategy() rest.RESTCreateStrategy
+	GetUpdateStrategy() rest.RESTUpdateStrategy
+	GetDeleteStrategy() rest.RESTDeleteStrategy
+	GetExportStrategy() rest.RESTExportStrategy
+}
+
+// Store implements pkg/api/rest.StandardStorage. It's intended to be
+// embeddable and allows the consumer to implement any non-generic functions
+// that are required. This object is intended to be copyable so that it can be
+// used in different ways but share the same underlying behavior.
+//
+// All fields are required unless specified.
+//
+// The intended use of this type is embedding within a Kind specific
+// RESTStorage implementation. This type provides CRUD semantics on a Kubelike
+// resource, handling details like conflict detection with ResourceVersion and
+// semantics. The RESTCreateStrategy, RESTUpdateStrategy, and
+// RESTDeleteStrategy are generic across all backends, and encapsulate logic
+// specific to the API.
+//
+// TODO: make the default exposed methods exactly match a generic RESTStorage
+type Store struct {
+	// NewFunc returns a new instance of the type this registry returns for a
+	// GET of a single object, e.g.:
+	//
+	// curl GET /apis/group/version/namespaces/my-ns/myresource/name-of-object
+	NewFunc func() runtime.Object
+
+	// NewListFunc returns a new list of the type this registry; it is the
+	// type returned when the resource is listed, e.g.:
+	//
+	// curl GET /apis/group/version/namespaces/my-ns/myresource
+	NewListFunc func() runtime.Object
+
+	// DefaultQualifiedResource is the pluralized name of the resource.
+	// This field is used if there is no request info present in the context.
+	// See qualifiedResourceFromContext for details.
+	DefaultQualifiedResource schema.GroupResource
+
+	// KeyRootFunc returns the root etcd key for this resource; should not
+	// include trailing "/".  This is used for operations that work on the
+	// entire collection (listing and watching).
+	//
+	// KeyRootFunc and KeyFunc must be supplied together or not at all.
+	KeyRootFunc func(ctx context.Context) string
+
+	// KeyFunc returns the key for a specific object in the collection.
+	// KeyFunc is called for Create/Update/Get/Delete. Note that 'namespace'
+	// can be gotten from ctx.
+	//
+	// KeyFunc and KeyRootFunc must be supplied together or not at all.
+	KeyFunc func(ctx context.Context, name string) (string, error)
+
+	// ObjectNameFunc returns the name of an object or an error.
+	ObjectNameFunc func(obj runtime.Object) (string, error)
+
+	// TTLFunc returns the TTL (time to live) that objects should be persisted
+	// with. The existing parameter is the current TTL or the default for this
+	// operation. The update parameter indicates whether this is an operation
+	// against an existing object.
+	//
+	// Objects that are persisted with a TTL are evicted once the TTL expires.
+	TTLFunc func(obj runtime.Object, existing uint64, update bool) (uint64, error)
+
+	// PredicateFunc returns a matcher corresponding to the provided labels
+	// and fields. The SelectionPredicate returned should return true if the
+	// object matches the given field and label selectors.
+	PredicateFunc func(label labels.Selector, field fields.Selector) storage.SelectionPredicate
+
+	// EnableGarbageCollection affects the handling of Update and Delete
+	// requests. Enabling garbage collection allows finalizers to do work to
+	// finalize this object before the store deletes it.
+	//
+	// If any store has garbage collection enabled, it must also be enabled in
+	// the kube-controller-manager.
+	EnableGarbageCollection bool
+
+	// DeleteCollectionWorkers is the maximum number of workers in a single
+	// DeleteCollection call. Delete requests for the items in a collection
+	// are issued in parallel.
+	DeleteCollectionWorkers int
+
+	// Decorator is an optional exit hook on an object returned from the
+	// underlying storage. The returned object could be an individual object
+	// (e.g. Pod) or a list type (e.g. PodList). Decorator is intended for
+	// integrations that are above storage and should only be used for
+	// specific cases where storage of the value is not appropriate, since
+	// they cannot be watched.
+	Decorator ObjectFunc
+	// CreateStrategy implements resource-specific behavior during creation.
+	CreateStrategy rest.RESTCreateStrategy
+	// AfterCreate implements a further operation to run after a resource is
+	// created and before it is decorated, optional.
+	AfterCreate ObjectFunc
+
+	// UpdateStrategy implements resource-specific behavior during updates.
+	UpdateStrategy rest.RESTUpdateStrategy
+	// AfterUpdate implements a further operation to run after a resource is
+	// updated and before it is decorated, optional.
+	AfterUpdate ObjectFunc
+
+	// DeleteStrategy implements resource-specific behavior during deletion.
+	DeleteStrategy rest.RESTDeleteStrategy
+	// AfterDelete implements a further operation to run after a resource is
+	// deleted and before it is decorated, optional.
+	AfterDelete ObjectFunc
+	// ReturnDeletedObject determines whether the Store returns the object
+	// that was deleted. Otherwise, return a generic success status response.
+	ReturnDeletedObject bool
+	// ExportStrategy implements resource-specific behavior during export,
+	// optional. Exported objects are not decorated.
+	ExportStrategy rest.RESTExportStrategy
+	// TableConvertor is an optional interface for transforming items or lists
+	// of items into tabular output. If unset, the default will be used.
+	TableConvertor rest.TableConvertor
+
+	// Storage is the interface for the underlying storage for the resource.
+	Storage storage.Interface
+	// Called to cleanup clients used by the underlying Storage; optional.
+	DestroyFunc func()
+}
+
+// Note: the rest.StandardStorage interface aggregates the common REST verbs
+var _ rest.StandardStorage = &Store{}
+var _ rest.Exporter = &Store{}
+var _ rest.TableConvertor = &Store{}
+var _ GenericStore = &Store{}
+
+const (
+	OptimisticLockErrorMsg        = "the object has been modified; please apply your changes to the latest version and try again"
+	resourceCountPollPeriodJitter = 1.2
+)
+
+// NamespaceKeyRootFunc is the default function for constructing storage paths
+// to resource directories enforcing namespace rules.
+func NamespaceKeyRootFunc(ctx context.Context, prefix string) string {
+	key := prefix
+	ns, ok := genericapirequest.NamespaceFrom(ctx)
+	if ok && len(ns) > 0 {
+		key = key + "/" + ns
+	}
+	return key
+}
+
+// NamespaceKeyFunc is the default function for constructing storage paths to
+// a resource relative to the given prefix enforcing namespace rules. If the
+// context does not contain a namespace, it errors.
+func NamespaceKeyFunc(ctx context.Context, prefix string, name string) (string, error) {
+	key := NamespaceKeyRootFunc(ctx, prefix)
+	ns, ok := genericapirequest.NamespaceFrom(ctx)
+	if !ok || len(ns) == 0 {
+		return "", kubeerr.NewBadRequest("Namespace parameter required.")
+	}
+	if len(name) == 0 {
+		return "", kubeerr.NewBadRequest("Name parameter required.")
+	}
+	if msgs := path.IsValidPathSegmentName(name); len(msgs) != 0 {
+		return "", kubeerr.NewBadRequest(fmt.Sprintf("Name parameter invalid: %q: %s", name, strings.Join(msgs, ";")))
+	}
+	key = key + "/" + name
+	return key, nil
+}
+
+// NoNamespaceKeyFunc is the default function for constructing storage paths
+// to a resource relative to the given prefix without a namespace.
+func NoNamespaceKeyFunc(ctx context.Context, prefix string, name string) (string, error) {
+	if len(name) == 0 {
+		return "", kubeerr.NewBadRequest("Name parameter required.")
+	}
+	if msgs := path.IsValidPathSegmentName(name); len(msgs) != 0 {
+		return "", kubeerr.NewBadRequest(fmt.Sprintf("Name parameter invalid: %q: %s", name, strings.Join(msgs, ";")))
+	}
+	key := prefix + "/" + name
+	return key, nil
+}
+
+// New implements RESTStorage.New.
+func (e *Store) New() runtime.Object {
+	return e.NewFunc()
+}
+
+// NewList implements rest.Lister.
+func (e *Store) NewList() runtime.Object {
+	return e.NewListFunc()
+}
+
+// NamespaceScoped indicates whether the resource is namespaced
+func (e *Store) NamespaceScoped() bool {
+	if e.CreateStrategy != nil {
+		return e.CreateStrategy.NamespaceScoped()
+	}
+	if e.UpdateStrategy != nil {
+		return e.UpdateStrategy.NamespaceScoped()
+	}
+
+	panic("programmer error: no CRUD for resource, you're crazy, override NamespaceScoped too")
+}
+
+// GetCreateStrategy implements GenericStore.
+func (e *Store) GetCreateStrategy() rest.RESTCreateStrategy {
+	return e.CreateStrategy
+}
+
+// GetUpdateStrategy implements GenericStore.
+func (e *Store) GetUpdateStrategy() rest.RESTUpdateStrategy {
+	return e.UpdateStrategy
+}
+
+// GetDeleteStrategy implements GenericStore.
+func (e *Store) GetDeleteStrategy() rest.RESTDeleteStrategy {
+	return e.DeleteStrategy
+}
+
+// GetExportStrategy implements GenericStore.
+func (e *Store) GetExportStrategy() rest.RESTExportStrategy {
+	return e.ExportStrategy
+}
+
+// List returns a list of items matching labels and field according to the
+// store's PredicateFunc.
+func (e *Store) List(ctx context.Context, options *metainternalversion.ListOptions) (runtime.Object, error) {
+	label := labels.Everything()
+	if options != nil && options.LabelSelector != nil {
+		label = options.LabelSelector
+	}
+	field := fields.Everything()
+	if options != nil && options.FieldSelector != nil {
+		field = options.FieldSelector
+	}
+	out, err := e.ListPredicate(ctx, e.PredicateFunc(label, field), options)
+	if err != nil {
+		return nil, err
+	}
+	if e.Decorator != nil {
+		if err := e.Decorator(out); err != nil {
+			return nil, err
+		}
+	}
+	return out, nil
+}
+
+// ListPredicate returns a list of all the items matching the given
+// SelectionPredicate.
+func (e *Store) ListPredicate(ctx context.Context, p storage.SelectionPredicate, options *metainternalversion.ListOptions) (runtime.Object, error) {
+	if options == nil {
+		// By default we should serve the request from etcd.
+		options = &metainternalversion.ListOptions{ResourceVersion: ""}
+	}
+	p.IncludeUninitialized = options.IncludeUninitialized
+	p.Limit = options.Limit
+	p.Continue = options.Continue
+	list := e.NewListFunc()
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	if name, ok := p.MatchesSingle(); ok {
+		if key, err := e.KeyFunc(ctx, name); err == nil {
+			err := e.Storage.GetToList(ctx, key, options.ResourceVersion, p, list)
+			return list, storeerr.InterpretListError(err, qualifiedResource)
+		}
+		// if we cannot extract a key based on the current context, the optimization is skipped
+	}
+
+	err := e.Storage.List(ctx, e.KeyRootFunc(ctx), options.ResourceVersion, p, list)
+	return list, storeerr.InterpretListError(err, qualifiedResource)
+}
+
+// Create inserts a new item according to the unique key from the object.
+func (e *Store) Create(ctx context.Context, obj runtime.Object, createValidation rest.ValidateObjectFunc, includeUninitialized bool) (runtime.Object, error) {
+	if err := rest.BeforeCreate(e.CreateStrategy, ctx, obj); err != nil {
+		return nil, err
+	}
+	// at this point we have a fully formed object.  It is time to call the validators that the apiserver
+	// handling chain wants to enforce.
+	if createValidation != nil {
+		if err := createValidation(obj.DeepCopyObject()); err != nil {
+			return nil, err
+		}
+	}
+
+	name, err := e.ObjectNameFunc(obj)
+	if err != nil {
+		return nil, err
+	}
+	key, err := e.KeyFunc(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	ttl, err := e.calculateTTL(obj, 0, false)
+	if err != nil {
+		return nil, err
+	}
+	out := e.NewFunc()
+	if err := e.Storage.Create(ctx, key, obj, out, ttl); err != nil {
+		err = storeerr.InterpretCreateError(err, qualifiedResource, name)
+		err = rest.CheckGeneratedNameError(e.CreateStrategy, err, obj)
+		if !kubeerr.IsAlreadyExists(err) {
+			return nil, err
+		}
+		if errGet := e.Storage.Get(ctx, key, "", out, false); errGet != nil {
+			return nil, err
+		}
+		accessor, errGetAcc := meta.Accessor(out)
+		if errGetAcc != nil {
+			return nil, err
+		}
+		if accessor.GetDeletionTimestamp() != nil {
+			msg := &err.(*kubeerr.StatusError).ErrStatus.Message
+			*msg = fmt.Sprintf("object is being deleted: %s", *msg)
+		}
+		return nil, err
+	}
+	if e.AfterCreate != nil {
+		if err := e.AfterCreate(out); err != nil {
+			return nil, err
+		}
+	}
+	if e.Decorator != nil {
+		if err := e.Decorator(out); err != nil {
+			return nil, err
+		}
+	}
+	if !includeUninitialized {
+		return e.WaitForInitialized(ctx, out)
+	}
+	return out, nil
+}
+
+// WaitForInitialized holds until the object is initialized, or returns an error if the default limit expires.
+// This method is exposed publicly for consumers of generic rest tooling.
+func (e *Store) WaitForInitialized(ctx context.Context, obj runtime.Object) (runtime.Object, error) {
+	// return early if we don't have initializers, or if they've completed already
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return obj, nil
+	}
+	initializers := accessor.GetInitializers()
+	if initializers == nil {
+		return obj, nil
+	}
+	if result := initializers.Result; result != nil {
+		return nil, kubeerr.FromObject(result)
+	}
+
+	key, err := e.KeyFunc(ctx, accessor.GetName())
+	if err != nil {
+		return nil, err
+	}
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	w, err := e.Storage.Watch(ctx, key, accessor.GetResourceVersion(), storage.SelectionPredicate{
+		Label: labels.Everything(),
+		Field: fields.Everything(),
+
+		IncludeUninitialized: true,
+	})
+	if err != nil {
+		return nil, err
+	}
+	defer w.Stop()
+
+	latest := obj
+	ch := w.ResultChan()
+	for {
+		select {
+		case event, ok := <-ch:
+			if !ok {
+				msg := fmt.Sprintf("server has timed out waiting for the initialization of %s %s",
+					qualifiedResource.String(), accessor.GetName())
+				return nil, kubeerr.NewTimeoutError(msg, 0)
+			}
+			switch event.Type {
+			case watch.Deleted:
+				if latest = event.Object; latest != nil {
+					if accessor, err := meta.Accessor(latest); err == nil {
+						if initializers := accessor.GetInitializers(); initializers != nil && initializers.Result != nil {
+							// initialization failed, but we missed the modification event
+							return nil, kubeerr.FromObject(initializers.Result)
+						}
+					}
+				}
+				return nil, kubeerr.NewInternalError(fmt.Errorf("object deleted while waiting for creation"))
+			case watch.Error:
+				if status, ok := event.Object.(*metav1.Status); ok {
+					return nil, &kubeerr.StatusError{ErrStatus: *status}
+				}
+				return nil, kubeerr.NewInternalError(fmt.Errorf("unexpected object in watch stream, can't complete initialization %T", event.Object))
+			case watch.Modified:
+				latest = event.Object
+				accessor, err = meta.Accessor(latest)
+				if err != nil {
+					return nil, kubeerr.NewInternalError(fmt.Errorf("object no longer has access to metadata %T: %v", latest, err))
+				}
+				initializers := accessor.GetInitializers()
+				if initializers == nil {
+					// completed initialization
+					return latest, nil
+				}
+				if result := initializers.Result; result != nil {
+					// initialization failed
+					return nil, kubeerr.FromObject(result)
+				}
+			}
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+	}
+}
+
+// shouldDeleteDuringUpdate checks if a Update is removing all the object's
+// finalizers. If so, it further checks if the object's
+// DeletionGracePeriodSeconds is 0.
+func (e *Store) shouldDeleteDuringUpdate(ctx context.Context, key string, obj, existing runtime.Object) bool {
+	newMeta, err := meta.Accessor(obj)
+	if err != nil {
+		utilruntime.HandleError(err)
+		return false
+	}
+	oldMeta, err := meta.Accessor(existing)
+	if err != nil {
+		utilruntime.HandleError(err)
+		return false
+	}
+	return len(newMeta.GetFinalizers()) == 0 && oldMeta.GetDeletionGracePeriodSeconds() != nil && *oldMeta.GetDeletionGracePeriodSeconds() == 0
+}
+
+// shouldDeleteForFailedInitialization returns true if the provided object is initializing and has
+// a failure recorded.
+func (e *Store) shouldDeleteForFailedInitialization(ctx context.Context, obj runtime.Object) bool {
+	m, err := meta.Accessor(obj)
+	if err != nil {
+		utilruntime.HandleError(err)
+		return false
+	}
+	if initializers := m.GetInitializers(); initializers != nil && initializers.Result != nil {
+		return true
+	}
+	return false
+}
+
+// deleteWithoutFinalizers handles deleting an object ignoring its finalizer list.
+// Used for objects that are either been finalized or have never initialized.
+func (e *Store) deleteWithoutFinalizers(ctx context.Context, name, key string, obj runtime.Object, preconditions *storage.Preconditions) (runtime.Object, bool, error) {
+	out := e.NewFunc()
+	glog.V(6).Infof("going to delete %s from registry, triggered by update", name)
+	if err := e.Storage.Delete(ctx, key, out, preconditions); err != nil {
+		// Deletion is racy, i.e., there could be multiple update
+		// requests to remove all finalizers from the object, so we
+		// ignore the NotFound error.
+		if storage.IsNotFound(err) {
+			_, err := e.finalizeDelete(ctx, obj, true)
+			// clients are expecting an updated object if a PUT succeeded,
+			// but finalizeDelete returns a metav1.Status, so return
+			// the object in the request instead.
+			return obj, false, err
+		}
+		return nil, false, storeerr.InterpretDeleteError(err, e.qualifiedResourceFromContext(ctx), name)
+	}
+	_, err := e.finalizeDelete(ctx, out, true)
+	// clients are expecting an updated object if a PUT succeeded, but
+	// finalizeDelete returns a metav1.Status, so return the object in
+	// the request instead.
+	return obj, false, err
+}
+
+// Update performs an atomic update and set of the object. Returns the result of the update
+// or an error. If the registry allows create-on-update, the create flow will be executed.
+// A bool is returned along with the object and any errors, to indicate object creation.
+func (e *Store) Update(ctx context.Context, name string, objInfo rest.UpdatedObjectInfo, createValidation rest.ValidateObjectFunc, updateValidation rest.ValidateObjectUpdateFunc) (runtime.Object, bool, error) {
+	key, err := e.KeyFunc(ctx, name)
+	if err != nil {
+		return nil, false, err
+	}
+
+	var (
+		creatingObj runtime.Object
+		creating    = false
+	)
+
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	storagePreconditions := &storage.Preconditions{}
+	if preconditions := objInfo.Preconditions(); preconditions != nil {
+		storagePreconditions.UID = preconditions.UID
+	}
+
+	out := e.NewFunc()
+	// deleteObj is only used in case a deletion is carried out
+	var deleteObj runtime.Object
+	err = e.Storage.GuaranteedUpdate(ctx, key, out, true, storagePreconditions, func(existing runtime.Object, res storage.ResponseMeta) (runtime.Object, *uint64, error) {
+		// Given the existing object, get the new object
+		obj, err := objInfo.UpdatedObject(ctx, existing)
+		if err != nil {
+			return nil, nil, err
+		}
+
+		// If AllowUnconditionalUpdate() is true and the object specified by
+		// the user does not have a resource version, then we populate it with
+		// the latest version. Else, we check that the version specified by
+		// the user matches the version of latest storage object.
+		resourceVersion, err := e.Storage.Versioner().ObjectResourceVersion(obj)
+		if err != nil {
+			return nil, nil, err
+		}
+		doUnconditionalUpdate := resourceVersion == 0 && e.UpdateStrategy.AllowUnconditionalUpdate()
+
+		version, err := e.Storage.Versioner().ObjectResourceVersion(existing)
+		if err != nil {
+			return nil, nil, err
+		}
+		if version == 0 {
+			if !e.UpdateStrategy.AllowCreateOnUpdate() {
+				return nil, nil, kubeerr.NewNotFound(qualifiedResource, name)
+			}
+			creating = true
+			creatingObj = obj
+			if err := rest.BeforeCreate(e.CreateStrategy, ctx, obj); err != nil {
+				return nil, nil, err
+			}
+			// at this point we have a fully formed object.  It is time to call the validators that the apiserver
+			// handling chain wants to enforce.
+			if createValidation != nil {
+				if err := createValidation(obj.DeepCopyObject()); err != nil {
+					return nil, nil, err
+				}
+			}
+			ttl, err := e.calculateTTL(obj, 0, false)
+			if err != nil {
+				return nil, nil, err
+			}
+
+			return obj, &ttl, nil
+		}
+
+		creating = false
+		creatingObj = nil
+		if doUnconditionalUpdate {
+			// Update the object's resource version to match the latest
+			// storage object's resource version.
+			err = e.Storage.Versioner().UpdateObject(obj, res.ResourceVersion)
+			if err != nil {
+				return nil, nil, err
+			}
+		} else {
+			// Check if the object's resource version matches the latest
+			// resource version.
+			if resourceVersion == 0 {
+				// TODO: The Invalid error should have a field for Resource.
+				// After that field is added, we should fill the Resource and
+				// leave the Kind field empty. See the discussion in #18526.
+				qualifiedKind := schema.GroupKind{Group: qualifiedResource.Group, Kind: qualifiedResource.Resource}
+				fieldErrList := field.ErrorList{field.Invalid(field.NewPath("metadata").Child("resourceVersion"), resourceVersion, "must be specified for an update")}
+				return nil, nil, kubeerr.NewInvalid(qualifiedKind, name, fieldErrList)
+			}
+			if resourceVersion != version {
+				return nil, nil, kubeerr.NewConflict(qualifiedResource, name, fmt.Errorf(OptimisticLockErrorMsg))
+			}
+		}
+		if err := rest.BeforeUpdate(e.UpdateStrategy, ctx, obj, existing); err != nil {
+			return nil, nil, err
+		}
+		// at this point we have a fully formed object.  It is time to call the validators that the apiserver
+		// handling chain wants to enforce.
+		if updateValidation != nil {
+			if err := updateValidation(obj.DeepCopyObject(), existing.DeepCopyObject()); err != nil {
+				return nil, nil, err
+			}
+		}
+		if e.shouldDeleteDuringUpdate(ctx, key, obj, existing) {
+			deleteObj = obj
+			return nil, nil, errEmptiedFinalizers
+		}
+		ttl, err := e.calculateTTL(obj, res.TTL, true)
+		if err != nil {
+			return nil, nil, err
+		}
+		if int64(ttl) != res.TTL {
+			return obj, &ttl, nil
+		}
+		return obj, nil, nil
+	})
+
+	if err != nil {
+		// delete the object
+		if err == errEmptiedFinalizers {
+			return e.deleteWithoutFinalizers(ctx, name, key, deleteObj, storagePreconditions)
+		}
+		if creating {
+			err = storeerr.InterpretCreateError(err, qualifiedResource, name)
+			err = rest.CheckGeneratedNameError(e.CreateStrategy, err, creatingObj)
+		} else {
+			err = storeerr.InterpretUpdateError(err, qualifiedResource, name)
+		}
+		return nil, false, err
+	}
+
+	if e.shouldDeleteForFailedInitialization(ctx, out) {
+		return e.deleteWithoutFinalizers(ctx, name, key, out, storagePreconditions)
+	}
+
+	if creating {
+		if e.AfterCreate != nil {
+			if err := e.AfterCreate(out); err != nil {
+				return nil, false, err
+			}
+		}
+	} else {
+		if e.AfterUpdate != nil {
+			if err := e.AfterUpdate(out); err != nil {
+				return nil, false, err
+			}
+		}
+	}
+	if e.Decorator != nil {
+		if err := e.Decorator(out); err != nil {
+			return nil, false, err
+		}
+	}
+	return out, creating, nil
+}
+
+// Get retrieves the item from storage.
+func (e *Store) Get(ctx context.Context, name string, options *metav1.GetOptions) (runtime.Object, error) {
+	obj := e.NewFunc()
+	key, err := e.KeyFunc(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	if err := e.Storage.Get(ctx, key, options.ResourceVersion, obj, false); err != nil {
+		return nil, storeerr.InterpretGetError(err, e.qualifiedResourceFromContext(ctx), name)
+	}
+	if e.Decorator != nil {
+		if err := e.Decorator(obj); err != nil {
+			return nil, err
+		}
+	}
+	return obj, nil
+}
+
+// qualifiedResourceFromContext attempts to retrieve a GroupResource from the context's request info.
+// If the context has no request info, DefaultQualifiedResource is used.
+func (e *Store) qualifiedResourceFromContext(ctx context.Context) schema.GroupResource {
+	if info, ok := genericapirequest.RequestInfoFrom(ctx); ok {
+		return schema.GroupResource{Group: info.APIGroup, Resource: info.Resource}
+	}
+	// some implementations access storage directly and thus the context has no RequestInfo
+	return e.DefaultQualifiedResource
+}
+
+var (
+	errAlreadyDeleting   = fmt.Errorf("abort delete")
+	errDeleteNow         = fmt.Errorf("delete now")
+	errEmptiedFinalizers = fmt.Errorf("emptied finalizers")
+)
+
+// shouldOrphanDependents returns true if the finalizer for orphaning should be set
+// updated for FinalizerOrphanDependents. In the order of highest to lowest
+// priority, there are three factors affect whether to add/remove the
+// FinalizerOrphanDependents: options, existing finalizers of the object,
+// and e.DeleteStrategy.DefaultGarbageCollectionPolicy.
+func shouldOrphanDependents(ctx context.Context, e *Store, accessor metav1.Object, options *metav1.DeleteOptions) bool {
+	// Get default GC policy from this REST object type
+	gcStrategy, ok := e.DeleteStrategy.(rest.GarbageCollectionDeleteStrategy)
+	var defaultGCPolicy rest.GarbageCollectionPolicy
+	if ok {
+		defaultGCPolicy = gcStrategy.DefaultGarbageCollectionPolicy(ctx)
+	}
+
+	if defaultGCPolicy == rest.Unsupported {
+		// return  false to indicate that we should NOT orphan
+		return false
+	}
+
+	// An explicit policy was set at deletion time, that overrides everything
+	if options != nil && options.OrphanDependents != nil {
+		return *options.OrphanDependents
+	}
+	if options != nil && options.PropagationPolicy != nil {
+		switch *options.PropagationPolicy {
+		case metav1.DeletePropagationOrphan:
+			return true
+		case metav1.DeletePropagationBackground, metav1.DeletePropagationForeground:
+			return false
+		}
+	}
+
+	// If a finalizer is set in the object, it overrides the default
+	// validation should make sure the two cases won't be true at the same time.
+	finalizers := accessor.GetFinalizers()
+	for _, f := range finalizers {
+		switch f {
+		case metav1.FinalizerOrphanDependents:
+			return true
+		case metav1.FinalizerDeleteDependents:
+			return false
+		}
+	}
+
+	// Get default orphan policy from this REST object type if it exists
+	if defaultGCPolicy == rest.OrphanDependents {
+		return true
+	}
+	return false
+}
+
+// shouldDeleteDependents returns true if the finalizer for foreground deletion should be set
+// updated for FinalizerDeleteDependents. In the order of highest to lowest
+// priority, there are three factors affect whether to add/remove the
+// FinalizerDeleteDependents: options, existing finalizers of the object, and
+// e.DeleteStrategy.DefaultGarbageCollectionPolicy.
+func shouldDeleteDependents(ctx context.Context, e *Store, accessor metav1.Object, options *metav1.DeleteOptions) bool {
+	// Get default GC policy from this REST object type
+	if gcStrategy, ok := e.DeleteStrategy.(rest.GarbageCollectionDeleteStrategy); ok && gcStrategy.DefaultGarbageCollectionPolicy(ctx) == rest.Unsupported {
+		// return false to indicate that we should NOT delete in foreground
+		return false
+	}
+
+	// If an explicit policy was set at deletion time, that overrides both
+	if options != nil && options.OrphanDependents != nil {
+		return false
+	}
+	if options != nil && options.PropagationPolicy != nil {
+		switch *options.PropagationPolicy {
+		case metav1.DeletePropagationForeground:
+			return true
+		case metav1.DeletePropagationBackground, metav1.DeletePropagationOrphan:
+			return false
+		}
+	}
+
+	// If a finalizer is set in the object, it overrides the default
+	// validation has made sure the two cases won't be true at the same time.
+	finalizers := accessor.GetFinalizers()
+	for _, f := range finalizers {
+		switch f {
+		case metav1.FinalizerDeleteDependents:
+			return true
+		case metav1.FinalizerOrphanDependents:
+			return false
+		}
+	}
+
+	return false
+}
+
+// deletionFinalizersForGarbageCollection analyzes the object and delete options
+// to determine whether the object is in need of finalization by the garbage
+// collector. If so, returns the set of deletion finalizers to apply and a bool
+// indicating whether the finalizer list has changed and is in need of updating.
+//
+// The finalizers returned are intended to be handled by the garbage collector.
+// If garbage collection is disabled for the store, this function returns false
+// to ensure finalizers aren't set which will never be cleared.
+func deletionFinalizersForGarbageCollection(ctx context.Context, e *Store, accessor metav1.Object, options *metav1.DeleteOptions) (bool, []string) {
+	if !e.EnableGarbageCollection {
+		return false, []string{}
+	}
+	shouldOrphan := shouldOrphanDependents(ctx, e, accessor, options)
+	shouldDeleteDependentInForeground := shouldDeleteDependents(ctx, e, accessor, options)
+	newFinalizers := []string{}
+
+	// first remove both finalizers, add them back if needed.
+	for _, f := range accessor.GetFinalizers() {
+		if f == metav1.FinalizerOrphanDependents || f == metav1.FinalizerDeleteDependents {
+			continue
+		}
+		newFinalizers = append(newFinalizers, f)
+	}
+
+	if shouldOrphan {
+		newFinalizers = append(newFinalizers, metav1.FinalizerOrphanDependents)
+	}
+	if shouldDeleteDependentInForeground {
+		newFinalizers = append(newFinalizers, metav1.FinalizerDeleteDependents)
+	}
+
+	oldFinalizerSet := sets.NewString(accessor.GetFinalizers()...)
+	newFinalizersSet := sets.NewString(newFinalizers...)
+	if oldFinalizerSet.Equal(newFinalizersSet) {
+		return false, accessor.GetFinalizers()
+	}
+	return true, newFinalizers
+}
+
+// markAsDeleting sets the obj's DeletionGracePeriodSeconds to 0, and sets the
+// DeletionTimestamp to "now". Finalizers are watching for such updates and will
+// finalize the object if their IDs are present in the object's Finalizers list.
+func markAsDeleting(obj runtime.Object) (err error) {
+	objectMeta, kerr := meta.Accessor(obj)
+	if kerr != nil {
+		return kerr
+	}
+	now := metav1.NewTime(time.Now())
+	// This handles Generation bump for resources that don't support graceful
+	// deletion. For resources that support graceful deletion is handle in
+	// pkg/api/rest/delete.go
+	if objectMeta.GetDeletionTimestamp() == nil && objectMeta.GetGeneration() > 0 {
+		objectMeta.SetGeneration(objectMeta.GetGeneration() + 1)
+	}
+	objectMeta.SetDeletionTimestamp(&now)
+	var zero int64 = 0
+	objectMeta.SetDeletionGracePeriodSeconds(&zero)
+	return nil
+}
+
+// updateForGracefulDeletionAndFinalizers updates the given object for
+// graceful deletion and finalization by setting the deletion timestamp and
+// grace period seconds (graceful deletion) and updating the list of
+// finalizers (finalization); it returns:
+//
+// 1. an error
+// 2. a boolean indicating that the object was not found, but it should be
+//    ignored
+// 3. a boolean indicating that the object's grace period is exhausted and it
+//    should be deleted immediately
+// 4. a new output object with the state that was updated
+// 5. a copy of the last existing state of the object
+func (e *Store) updateForGracefulDeletionAndFinalizers(ctx context.Context, name, key string, options *metav1.DeleteOptions, preconditions storage.Preconditions, in runtime.Object) (err error, ignoreNotFound, deleteImmediately bool, out, lastExisting runtime.Object) {
+	lastGraceful := int64(0)
+	var pendingFinalizers bool
+	out = e.NewFunc()
+	err = e.Storage.GuaranteedUpdate(
+		ctx,
+		key,
+		out,
+		false, /* ignoreNotFound */
+		&preconditions,
+		storage.SimpleUpdate(func(existing runtime.Object) (runtime.Object, error) {
+			graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, existing, options)
+			if err != nil {
+				return nil, err
+			}
+			if pendingGraceful {
+				return nil, errAlreadyDeleting
+			}
+
+			// Add/remove the orphan finalizer as the options dictates.
+			// Note that this occurs after checking pendingGraceufl, so
+			// finalizers cannot be updated via DeleteOptions if deletion has
+			// started.
+			existingAccessor, err := meta.Accessor(existing)
+			if err != nil {
+				return nil, err
+			}
+			needsUpdate, newFinalizers := deletionFinalizersForGarbageCollection(ctx, e, existingAccessor, options)
+			if needsUpdate {
+				existingAccessor.SetFinalizers(newFinalizers)
+			}
+
+			pendingFinalizers = len(existingAccessor.GetFinalizers()) != 0
+			if !graceful {
+				// set the DeleteGracePeriods to 0 if the object has pendingFinalizers but not supporting graceful deletion
+				if pendingFinalizers {
+					glog.V(6).Infof("update the DeletionTimestamp to \"now\" and GracePeriodSeconds to 0 for object %s, because it has pending finalizers", name)
+					err = markAsDeleting(existing)
+					if err != nil {
+						return nil, err
+					}
+					return existing, nil
+				}
+				return nil, errDeleteNow
+			}
+			lastGraceful = *options.GracePeriodSeconds
+			lastExisting = existing
+			return existing, nil
+		}),
+	)
+	switch err {
+	case nil:
+		// If there are pending finalizers, we never delete the object immediately.
+		if pendingFinalizers {
+			return nil, false, false, out, lastExisting
+		}
+		if lastGraceful > 0 {
+			return nil, false, false, out, lastExisting
+		}
+		// If we are here, the registry supports grace period mechanism and
+		// we are intentionally delete gracelessly. In this case, we may
+		// enter a race with other k8s components. If other component wins
+		// the race, the object will not be found, and we should tolerate
+		// the NotFound error. See
+		// https://github.com/kubernetes/kubernetes/issues/19403 for
+		// details.
+		return nil, true, true, out, lastExisting
+	case errDeleteNow:
+		// we've updated the object to have a zero grace period, or it's already at 0, so
+		// we should fall through and truly delete the object.
+		return nil, false, true, out, lastExisting
+	case errAlreadyDeleting:
+		out, err = e.finalizeDelete(ctx, in, true)
+		return err, false, false, out, lastExisting
+	default:
+		return storeerr.InterpretUpdateError(err, e.qualifiedResourceFromContext(ctx), name), false, false, out, lastExisting
+	}
+}
+
+// Delete removes the item from storage.
+func (e *Store) Delete(ctx context.Context, name string, options *metav1.DeleteOptions) (runtime.Object, bool, error) {
+	key, err := e.KeyFunc(ctx, name)
+	if err != nil {
+		return nil, false, err
+	}
+	obj := e.NewFunc()
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	if err := e.Storage.Get(ctx, key, "", obj, false); err != nil {
+		return nil, false, storeerr.InterpretDeleteError(err, qualifiedResource, name)
+	}
+	// support older consumers of delete by treating "nil" as delete immediately
+	if options == nil {
+		options = metav1.NewDeleteOptions(0)
+	}
+	var preconditions storage.Preconditions
+	if options.Preconditions != nil {
+		preconditions.UID = options.Preconditions.UID
+	}
+	graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, obj, options)
+	if err != nil {
+		return nil, false, err
+	}
+	// this means finalizers cannot be updated via DeleteOptions if a deletion is already pending
+	if pendingGraceful {
+		out, err := e.finalizeDelete(ctx, obj, false)
+		return out, false, err
+	}
+	// check if obj has pending finalizers
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return nil, false, kubeerr.NewInternalError(err)
+	}
+	pendingFinalizers := len(accessor.GetFinalizers()) != 0
+	var ignoreNotFound bool
+	var deleteImmediately bool = true
+	var lastExisting, out runtime.Object
+
+	// Handle combinations of graceful deletion and finalization by issuing
+	// the correct updates.
+	shouldUpdateFinalizers, _ := deletionFinalizersForGarbageCollection(ctx, e, accessor, options)
+	// TODO: remove the check, because we support no-op updates now.
+	if graceful || pendingFinalizers || shouldUpdateFinalizers {
+		err, ignoreNotFound, deleteImmediately, out, lastExisting = e.updateForGracefulDeletionAndFinalizers(ctx, name, key, options, preconditions, obj)
+	}
+
+	// !deleteImmediately covers all cases where err != nil. We keep both to be future-proof.
+	if !deleteImmediately || err != nil {
+		return out, false, err
+	}
+
+	// delete immediately, or no graceful deletion supported
+	glog.V(6).Infof("going to delete %s from registry: ", name)
+	out = e.NewFunc()
+	if err := e.Storage.Delete(ctx, key, out, &preconditions); err != nil {
+		// Please refer to the place where we set ignoreNotFound for the reason
+		// why we ignore the NotFound error .
+		if storage.IsNotFound(err) && ignoreNotFound && lastExisting != nil {
+			// The lastExisting object may not be the last state of the object
+			// before its deletion, but it's the best approximation.
+			out, err := e.finalizeDelete(ctx, lastExisting, true)
+			return out, true, err
+		}
+		return nil, false, storeerr.InterpretDeleteError(err, qualifiedResource, name)
+	}
+	out, err = e.finalizeDelete(ctx, out, true)
+	return out, true, err
+}
+
+// DeleteCollection removes all items returned by List with a given ListOptions from storage.
+//
+// DeleteCollection is currently NOT atomic. It can happen that only subset of objects
+// will be deleted from storage, and then an error will be returned.
+// In case of success, the list of deleted objects will be returned.
+//
+// TODO: Currently, there is no easy way to remove 'directory' entry from storage (if we
+// are removing all objects of a given type) with the current API (it's technically
+// possibly with storage API, but watch is not delivered correctly then).
+// It will be possible to fix it with v3 etcd API.
+func (e *Store) DeleteCollection(ctx context.Context, options *metav1.DeleteOptions, listOptions *metainternalversion.ListOptions) (runtime.Object, error) {
+	if listOptions == nil {
+		listOptions = &metainternalversion.ListOptions{}
+	} else {
+		listOptions = listOptions.DeepCopy()
+	}
+
+	// DeleteCollection must remain backwards compatible with old clients that expect it to
+	// remove all resources, initialized or not, within the type. It is also consistent with
+	// Delete which does not require IncludeUninitialized
+	listOptions.IncludeUninitialized = true
+
+	listObj, err := e.List(ctx, listOptions)
+	if err != nil {
+		return nil, err
+	}
+	items, err := meta.ExtractList(listObj)
+	if err != nil {
+		return nil, err
+	}
+	// Spawn a number of goroutines, so that we can issue requests to storage
+	// in parallel to speed up deletion.
+	// TODO: Make this proportional to the number of items to delete, up to
+	// DeleteCollectionWorkers (it doesn't make much sense to spawn 16
+	// workers to delete 10 items).
+	workersNumber := e.DeleteCollectionWorkers
+	if workersNumber < 1 {
+		workersNumber = 1
+	}
+	wg := sync.WaitGroup{}
+	toProcess := make(chan int, 2*workersNumber)
+	errs := make(chan error, workersNumber+1)
+
+	go func() {
+		defer utilruntime.HandleCrash(func(panicReason interface{}) {
+			errs <- fmt.Errorf("DeleteCollection distributor panicked: %v", panicReason)
+		})
+		for i := 0; i < len(items); i++ {
+			toProcess <- i
+		}
+		close(toProcess)
+	}()
+
+	wg.Add(workersNumber)
+	for i := 0; i < workersNumber; i++ {
+		go func() {
+			// panics don't cross goroutine boundaries
+			defer utilruntime.HandleCrash(func(panicReason interface{}) {
+				errs <- fmt.Errorf("DeleteCollection goroutine panicked: %v", panicReason)
+			})
+			defer wg.Done()
+
+			for index := range toProcess {
+				accessor, err := meta.Accessor(items[index])
+				if err != nil {
+					errs <- err
+					return
+				}
+				if _, _, err := e.Delete(ctx, accessor.GetName(), options); err != nil && !kubeerr.IsNotFound(err) {
+					glog.V(4).Infof("Delete %s in DeleteCollection failed: %v", accessor.GetName(), err)
+					errs <- err
+					return
+				}
+			}
+		}()
+	}
+	wg.Wait()
+	select {
+	case err := <-errs:
+		return nil, err
+	default:
+		return listObj, nil
+	}
+}
+
+// finalizeDelete runs the Store's AfterDelete hook if runHooks is set and
+// returns the decorated deleted object if appropriate.
+func (e *Store) finalizeDelete(ctx context.Context, obj runtime.Object, runHooks bool) (runtime.Object, error) {
+	if runHooks && e.AfterDelete != nil {
+		if err := e.AfterDelete(obj); err != nil {
+			return nil, err
+		}
+	}
+	if e.ReturnDeletedObject {
+		if e.Decorator != nil {
+			if err := e.Decorator(obj); err != nil {
+				return nil, err
+			}
+		}
+		return obj, nil
+	}
+	// Return information about the deleted object, which enables clients to
+	// verify that the object was actually deleted and not waiting for finalizers.
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return nil, err
+	}
+	qualifiedResource := e.qualifiedResourceFromContext(ctx)
+	details := &metav1.StatusDetails{
+		Name:  accessor.GetName(),
+		Group: qualifiedResource.Group,
+		Kind:  qualifiedResource.Resource, // Yes we set Kind field to resource.
+		UID:   accessor.GetUID(),
+	}
+	status := &metav1.Status{Status: metav1.StatusSuccess, Details: details}
+	return status, nil
+}
+
+// Watch makes a matcher for the given label and field, and calls
+// WatchPredicate. If possible, you should customize PredicateFunc to produce
+// a matcher that matches by key. SelectionPredicate does this for you
+// automatically.
+func (e *Store) Watch(ctx context.Context, options *metainternalversion.ListOptions) (watch.Interface, error) {
+	label := labels.Everything()
+	if options != nil && options.LabelSelector != nil {
+		label = options.LabelSelector
+	}
+	field := fields.Everything()
+	if options != nil && options.FieldSelector != nil {
+		field = options.FieldSelector
+	}
+	predicate := e.PredicateFunc(label, field)
+
+	resourceVersion := ""
+	if options != nil {
+		resourceVersion = options.ResourceVersion
+		predicate.IncludeUninitialized = options.IncludeUninitialized
+	}
+	return e.WatchPredicate(ctx, predicate, resourceVersion)
+}
+
+// WatchPredicate starts a watch for the items that matches.
+func (e *Store) WatchPredicate(ctx context.Context, p storage.SelectionPredicate, resourceVersion string) (watch.Interface, error) {
+	if name, ok := p.MatchesSingle(); ok {
+		if key, err := e.KeyFunc(ctx, name); err == nil {
+			w, err := e.Storage.Watch(ctx, key, resourceVersion, p)
+			if err != nil {
+				return nil, err
+			}
+			if e.Decorator != nil {
+				return newDecoratedWatcher(w, e.Decorator), nil
+			}
+			return w, nil
+		}
+		// if we cannot extract a key based on the current context, the
+		// optimization is skipped
+	}
+
+	w, err := e.Storage.WatchList(ctx, e.KeyRootFunc(ctx), resourceVersion, p)
+	if err != nil {
+		return nil, err
+	}
+	if e.Decorator != nil {
+		return newDecoratedWatcher(w, e.Decorator), nil
+	}
+	return w, nil
+}
+
+// calculateTTL is a helper for retrieving the updated TTL for an object or
+// returning an error if the TTL cannot be calculated. The defaultTTL is
+// changed to 1 if less than zero. Zero means no TTL, not expire immediately.
+func (e *Store) calculateTTL(obj runtime.Object, defaultTTL int64, update bool) (ttl uint64, err error) {
+	// TODO: validate this is assertion is still valid.
+
+	// etcd may return a negative TTL for a node if the expiration has not
+	// occurred due to server lag - we will ensure that the value is at least
+	// set.
+	if defaultTTL < 0 {
+		defaultTTL = 1
+	}
+	ttl = uint64(defaultTTL)
+	if e.TTLFunc != nil {
+		ttl, err = e.TTLFunc(obj, ttl, update)
+	}
+	return ttl, err
+}
+
+// exportObjectMeta unsets the fields on the given object that should not be
+// present when the object is exported.
+func exportObjectMeta(accessor metav1.Object, exact bool) {
+	accessor.SetUID("")
+	if !exact {
+		accessor.SetNamespace("")
+	}
+	accessor.SetCreationTimestamp(metav1.Time{})
+	accessor.SetDeletionTimestamp(nil)
+	accessor.SetResourceVersion("")
+	accessor.SetSelfLink("")
+	if len(accessor.GetGenerateName()) > 0 && !exact {
+		accessor.SetName("")
+	}
+}
+
+// Export implements the rest.Exporter interface
+func (e *Store) Export(ctx context.Context, name string, opts metav1.ExportOptions) (runtime.Object, error) {
+	obj, err := e.Get(ctx, name, &metav1.GetOptions{})
+	if err != nil {
+		return nil, err
+	}
+	if accessor, err := meta.Accessor(obj); err == nil {
+		exportObjectMeta(accessor, opts.Exact)
+	} else {
+		glog.V(4).Infof("Object of type %v does not have ObjectMeta: %v", reflect.TypeOf(obj), err)
+	}
+
+	if e.ExportStrategy != nil {
+		if err = e.ExportStrategy.Export(ctx, obj, opts.Exact); err != nil {
+			return nil, err
+		}
+	} else {
+		e.CreateStrategy.PrepareForCreate(ctx, obj)
+	}
+	return obj, nil
+}
+
+// CompleteWithOptions updates the store with the provided options and
+// defaults common fields.
+func (e *Store) CompleteWithOptions(options *generic.StoreOptions) error {
+	if e.DefaultQualifiedResource.Empty() {
+		return fmt.Errorf("store %#v must have a non-empty qualified resource", e)
+	}
+	if e.NewFunc == nil {
+		return fmt.Errorf("store for %s must have NewFunc set", e.DefaultQualifiedResource.String())
+	}
+	if e.NewListFunc == nil {
+		return fmt.Errorf("store for %s must have NewListFunc set", e.DefaultQualifiedResource.String())
+	}
+	if (e.KeyRootFunc == nil) != (e.KeyFunc == nil) {
+		return fmt.Errorf("store for %s must set both KeyRootFunc and KeyFunc or neither", e.DefaultQualifiedResource.String())
+	}
+
+	var isNamespaced bool
+	switch {
+	case e.CreateStrategy != nil:
+		isNamespaced = e.CreateStrategy.NamespaceScoped()
+	case e.UpdateStrategy != nil:
+		isNamespaced = e.UpdateStrategy.NamespaceScoped()
+	default:
+		return fmt.Errorf("store for %s must have CreateStrategy or UpdateStrategy set", e.DefaultQualifiedResource.String())
+	}
+
+	if e.DeleteStrategy == nil {
+		return fmt.Errorf("store for %s must have DeleteStrategy set", e.DefaultQualifiedResource.String())
+	}
+
+	if options.RESTOptions == nil {
+		return fmt.Errorf("options for %s must have RESTOptions set", e.DefaultQualifiedResource.String())
+	}
+
+	attrFunc := options.AttrFunc
+	if attrFunc == nil {
+		if isNamespaced {
+			attrFunc = storage.DefaultNamespaceScopedAttr
+		} else {
+			attrFunc = storage.DefaultClusterScopedAttr
+		}
+	}
+	if e.PredicateFunc == nil {
+		e.PredicateFunc = func(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
+			return storage.SelectionPredicate{
+				Label:    label,
+				Field:    field,
+				GetAttrs: attrFunc,
+			}
+		}
+	}
+
+	opts, err := options.RESTOptions.GetRESTOptions(e.DefaultQualifiedResource)
+	if err != nil {
+		return err
+	}
+
+	// ResourcePrefix must come from the underlying factory
+	prefix := opts.ResourcePrefix
+	if !strings.HasPrefix(prefix, "/") {
+		prefix = "/" + prefix
+	}
+	if prefix == "/" {
+		return fmt.Errorf("store for %s has an invalid prefix %q", e.DefaultQualifiedResource.String(), opts.ResourcePrefix)
+	}
+
+	// Set the default behavior for storage key generation
+	if e.KeyRootFunc == nil && e.KeyFunc == nil {
+		if isNamespaced {
+			e.KeyRootFunc = func(ctx context.Context) string {
+				return NamespaceKeyRootFunc(ctx, prefix)
+			}
+			e.KeyFunc = func(ctx context.Context, name string) (string, error) {
+				return NamespaceKeyFunc(ctx, prefix, name)
+			}
+		} else {
+			e.KeyRootFunc = func(ctx context.Context) string {
+				return prefix
+			}
+			e.KeyFunc = func(ctx context.Context, name string) (string, error) {
+				return NoNamespaceKeyFunc(ctx, prefix, name)
+			}
+		}
+	}
+
+	// We adapt the store's keyFunc so that we can use it with the StorageDecorator
+	// without making any assumptions about where objects are stored in etcd
+	keyFunc := func(obj runtime.Object) (string, error) {
+		accessor, err := meta.Accessor(obj)
+		if err != nil {
+			return "", err
+		}
+
+		if isNamespaced {
+			return e.KeyFunc(genericapirequest.WithNamespace(genericapirequest.NewContext(), accessor.GetNamespace()), accessor.GetName())
+		}
+
+		return e.KeyFunc(genericapirequest.NewContext(), accessor.GetName())
+	}
+
+	triggerFunc := options.TriggerFunc
+	if triggerFunc == nil {
+		triggerFunc = storage.NoTriggerPublisher
+	}
+
+	if e.DeleteCollectionWorkers == 0 {
+		e.DeleteCollectionWorkers = opts.DeleteCollectionWorkers
+	}
+
+	e.EnableGarbageCollection = opts.EnableGarbageCollection
+
+	if e.ObjectNameFunc == nil {
+		e.ObjectNameFunc = func(obj runtime.Object) (string, error) {
+			accessor, err := meta.Accessor(obj)
+			if err != nil {
+				return "", err
+			}
+			return accessor.GetName(), nil
+		}
+	}
+
+	if e.Storage == nil {
+		e.Storage, e.DestroyFunc = opts.Decorator(
+			opts.StorageConfig,
+			e.NewFunc(),
+			prefix,
+			keyFunc,
+			e.NewListFunc,
+			attrFunc,
+			triggerFunc,
+		)
+
+		if opts.CountMetricPollPeriod > 0 {
+			stopFunc := e.startObservingCount(opts.CountMetricPollPeriod)
+			previousDestroy := e.DestroyFunc
+			e.DestroyFunc = func() {
+				stopFunc()
+				if previousDestroy != nil {
+					previousDestroy()
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+// startObservingCount starts monitoring given prefix and periodically updating metrics. It returns a function to stop collection.
+func (e *Store) startObservingCount(period time.Duration) func() {
+	prefix := e.KeyRootFunc(genericapirequest.NewContext())
+	resourceName := e.DefaultQualifiedResource.String()
+	glog.V(2).Infof("Monitoring %v count at <storage-prefix>/%v", resourceName, prefix)
+	stopCh := make(chan struct{})
+	go wait.JitterUntil(func() {
+		count, err := e.Storage.Count(prefix)
+		if err != nil {
+			glog.V(5).Infof("Failed to update storage count metric: %v", err)
+			metrics.UpdateObjectCount(resourceName, -1)
+		} else {
+			metrics.UpdateObjectCount(resourceName, count)
+		}
+	}, period, resourceCountPollPeriodJitter, true, stopCh)
+	return func() { close(stopCh) }
+}
+
+func (e *Store) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1beta1.Table, error) {
+	if e.TableConvertor != nil {
+		return e.TableConvertor.ConvertToTable(ctx, object, tableOptions)
+	}
+	return rest.NewDefaultTableConvertor(e.qualifiedResourceFromContext(ctx)).ConvertToTable(ctx, object, tableOptions)
+}
diff --git a/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/storage_decorator.go b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/storage_decorator.go
new file mode 100644
index 0000000..94a4794
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apiserver/pkg/registry/generic/storage_decorator.go
@@ -0,0 +1,60 @@
+/*
+Copyright 2015 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 generic
+
+import (
+	"github.com/golang/glog"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apiserver/pkg/storage"
+	"k8s.io/apiserver/pkg/storage/storagebackend"
+	"k8s.io/apiserver/pkg/storage/storagebackend/factory"
+)
+
+// StorageDecorator is a function signature for producing a storage.Interface
+// and an associated DestroyFunc from given parameters.
+type StorageDecorator func(
+	config *storagebackend.Config,
+	objectType runtime.Object,
+	resourcePrefix string,
+	keyFunc func(obj runtime.Object) (string, error),
+	newListFunc func() runtime.Object,
+	getAttrsFunc storage.AttrFunc,
+	trigger storage.TriggerPublisherFunc) (storage.Interface, factory.DestroyFunc)
+
+// UndecoratedStorage returns the given a new storage from the given config
+// without any decoration.
+func UndecoratedStorage(
+	config *storagebackend.Config,
+	objectType runtime.Object,
+	resourcePrefix string,
+	keyFunc func(obj runtime.Object) (string, error),
+	newListFunc func() runtime.Object,
+	getAttrsFunc storage.AttrFunc,
+	trigger storage.TriggerPublisherFunc) (storage.Interface, factory.DestroyFunc) {
+	return NewRawStorage(config)
+}
+
+// NewRawStorage creates the low level kv storage. This is a work-around for current
+// two layer of same storage interface.
+// TODO: Once cacher is enabled on all registries (event registry is special), we will remove this method.
+func NewRawStorage(config *storagebackend.Config) (storage.Interface, factory.DestroyFunc) {
+	s, d, err := factory.Create(*config)
+	if err != nil {
+		glog.Fatalf("Unable to create storage backend: config (%v), err (%v)", config, err)
+	}
+	return s, d
+}