Merge pull request #45431 from DirectXMan12/feature/fake-dynamic-client

Automatic merge from submit-queue (batch tested with PRs 48224, 45431, 45946, 48775, 49396)

[client-go] Fake Dynamic Client

This commit converts `"k8s.io/client-go/dynamic".Client` to an interface, and implements fake versions of both `ClientPool` and `Client`.  This allows components which make uses of these clients to be tested in the same way that clientset-based components can be tested, using the standard `testing.Fake` machinery.

**Release note**:
```release-note
NONE
```

hack/.golint_failures

@@ -690,6 +690,7 @@ staging/src/k8s.io/apiserver/plugin/pkg/authorizer/webhook
 staging/src/k8s.io/client-go/discovery/cached
 staging/src/k8s.io/client-go/discovery/fake
 staging/src/k8s.io/client-go/dynamic
+staging/src/k8s.io/client-go/dynamic/fake
 staging/src/k8s.io/client-go/examples/workqueue
 staging/src/k8s.io/client-go/informers/internalinterfaces
 staging/src/k8s.io/client-go/kubernetes

pkg/controller/garbagecollector/graph_builder.go

@@ -97,7 +97,7 @@ type GraphBuilder struct {
 	ignoredResources map[schema.GroupResource]struct{}
 }
 
-func listWatcher(client *dynamic.Client, resource schema.GroupVersionResource) *cache.ListWatch {
+func listWatcher(client dynamic.Interface, resource schema.GroupVersionResource) *cache.ListWatch {
 	return &cache.ListWatch{
 		ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
 			// APIResource.Kind is not used by the dynamic client, so

pkg/controller/garbagecollector/rate_limiter_helper.go

@@ -46,7 +46,7 @@ func NewRegisteredRateLimiter(resources map[schema.GroupVersionResource]struct{}
 	return &RegisteredRateLimiter{rateLimiters: rateLimiters}
 }
 
-func (r *RegisteredRateLimiter) registerIfNotPresent(gv schema.GroupVersion, client *dynamic.Client, prefix string) {
+func (r *RegisteredRateLimiter) registerIfNotPresent(gv schema.GroupVersion, client dynamic.Interface, prefix string) {
 	once, found := r.rateLimiters[gv]
 	if !found {
 		return

pkg/controller/namespace/deletion/namespaced_resources_deleter.go

@@ -325,7 +325,7 @@ func (d *namespacedResourcesDeleter) finalizeNamespace(namespace *v1.Namespace)
 // it returns true if the operation was supported on the server.
 // it returns an error if the operation was supported on the server but was unable to complete.
 func (d *namespacedResourcesDeleter) deleteCollection(
-	dynamicClient *dynamic.Client, gvr schema.GroupVersionResource,
+	dynamicClient dynamic.Interface, gvr schema.GroupVersionResource,
 	namespace string) (bool, error) {
 	glog.V(5).Infof("namespace controller - deleteCollection - namespace: %s, gvr: %v", namespace, gvr)
 
@@ -370,7 +370,7 @@ func (d *namespacedResourcesDeleter) deleteCollection(
 //  a boolean if the operation is supported
 //  an error if the operation is supported but could not be completed.
 func (d *namespacedResourcesDeleter) listCollection(
-	dynamicClient *dynamic.Client, gvr schema.GroupVersionResource, namespace string) (*unstructured.UnstructuredList, bool, error) {
+	dynamicClient dynamic.Interface, gvr schema.GroupVersionResource, namespace string) (*unstructured.UnstructuredList, bool, error) {
 	glog.V(5).Infof("namespace controller - listCollection - namespace: %s, gvr: %v", namespace, gvr)
 
 	key := operationKey{operation: operationList, gvr: gvr}
@@ -406,7 +406,7 @@ func (d *namespacedResourcesDeleter) listCollection(
 
 // deleteEachItem is a helper function that will list the collection of resources and delete each item 1 by 1.
 func (d *namespacedResourcesDeleter) deleteEachItem(
-	dynamicClient *dynamic.Client, gvr schema.GroupVersionResource, namespace string) error {
+	dynamicClient dynamic.Interface, gvr schema.GroupVersionResource, namespace string) error {
 	glog.V(5).Infof("namespace controller - deleteEachItem - namespace: %s, gvr: %v", namespace, gvr)
 
 	unstructuredList, listSupported, err := d.listCollection(dynamicClient, gvr, namespace)

pkg/printers/internalversion/describe.go

@@ -180,13 +180,13 @@ func DescriberFor(kind schema.GroupKind, c clientset.Interface) (printers.Descri
 
 // GenericDescriberFor returns a generic describer for the specified mapping
 // that uses only information available from runtime.Unstructured
-func GenericDescriberFor(mapping *meta.RESTMapping, dynamic *dynamic.Client, events coreclient.EventsGetter) printers.Describer {
+func GenericDescriberFor(mapping *meta.RESTMapping, dynamic dynamic.Interface, events coreclient.EventsGetter) printers.Describer {
 	return &genericDescriber{mapping, dynamic, events}
 }
 
 type genericDescriber struct {
 	mapping *meta.RESTMapping
-	dynamic *dynamic.Client
+	dynamic dynamic.Interface
 	events  coreclient.EventsGetter
 }
 

staging/src/k8s.io/apiextensions-apiserver/test/integration/basic_test.go

@@ -75,7 +75,7 @@ func TestClusterScopedCRUD(t *testing.T) {
 	testSimpleCRUD(t, ns, noxuDefinition, noxuVersionClient)
 }
 
-func testSimpleCRUD(t *testing.T, ns string, noxuDefinition *apiextensionsv1beta1.CustomResourceDefinition, noxuVersionClient *dynamic.Client) {
+func testSimpleCRUD(t *testing.T, ns string, noxuDefinition *apiextensionsv1beta1.CustomResourceDefinition, noxuVersionClient dynamic.Interface) {
 	noxuResourceClient := NewNamespacedCustomResourceClient(ns, noxuVersionClient, noxuDefinition)
 	initialList, err := noxuResourceClient.List(metav1.ListOptions{})
 	if err != nil {
@@ -501,7 +501,7 @@ func TestCrossNamespaceListWatch(t *testing.T) {
 	checkNamespacesWatchHelper(t, ns2, noxuNamespacesWatch2)
 }
 
-func createInstanceWithNamespaceHelper(t *testing.T, ns string, name string, noxuNamespacedResourceClient *dynamic.ResourceClient, noxuDefinition *apiextensionsv1beta1.CustomResourceDefinition) *unstructured.Unstructured {
+func createInstanceWithNamespaceHelper(t *testing.T, ns string, name string, noxuNamespacedResourceClient dynamic.ResourceInterface, noxuDefinition *apiextensionsv1beta1.CustomResourceDefinition) *unstructured.Unstructured {
 	createdInstance, err := instantiateCustomResource(t, testserver.NewNoxuInstance(ns, name), noxuNamespacedResourceClient, noxuDefinition)
 	if err != nil {
 		t.Fatalf("unable to create noxu Instance:%v", err)

staging/src/k8s.io/apiextensions-apiserver/test/integration/registration_test.go

@@ -39,7 +39,7 @@ import (
 	"k8s.io/client-go/dynamic"
 )
 
-func instantiateCustomResource(t *testing.T, instanceToCreate *unstructured.Unstructured, client *dynamic.ResourceClient, definition *apiextensionsv1beta1.CustomResourceDefinition) (*unstructured.Unstructured, error) {
+func instantiateCustomResource(t *testing.T, instanceToCreate *unstructured.Unstructured, client dynamic.ResourceInterface, definition *apiextensionsv1beta1.CustomResourceDefinition) (*unstructured.Unstructured, error) {
 	createdInstance, err := client.Create(instanceToCreate)
 	if err != nil {
 		t.Logf("%#v", createdInstance)
@@ -66,7 +66,7 @@ func instantiateCustomResource(t *testing.T, instanceToCreate *unstructured.Unst
 	return createdInstance, nil
 }
 
-func NewNamespacedCustomResourceClient(ns string, client *dynamic.Client, definition *apiextensionsv1beta1.CustomResourceDefinition) *dynamic.ResourceClient {
+func NewNamespacedCustomResourceClient(ns string, client dynamic.Interface, definition *apiextensionsv1beta1.CustomResourceDefinition) dynamic.ResourceInterface {
 	return client.Resource(&metav1.APIResource{
 		Name:       definition.Spec.Names.Plural,
 		Namespaced: definition.Spec.Scope == apiextensionsv1beta1.NamespaceScoped,

staging/src/k8s.io/apiextensions-apiserver/test/integration/testserver/resources.go

@@ -141,7 +141,7 @@ func NewCurletInstance(namespace, name string) *unstructured.Unstructured {
 	}
 }
 
-func CreateNewCustomResourceDefinition(crd *apiextensionsv1beta1.CustomResourceDefinition, apiExtensionsClient clientset.Interface, clientPool dynamic.ClientPool) (*dynamic.Client, error) {
+func CreateNewCustomResourceDefinition(crd *apiextensionsv1beta1.CustomResourceDefinition, apiExtensionsClient clientset.Interface, clientPool dynamic.ClientPool) (dynamic.Interface, error) {
 	_, err := apiExtensionsClient.Apiextensions().CustomResourceDefinitions().Create(crd)
 	if err != nil {
 		return nil, err
@@ -194,7 +194,7 @@ func CreateNewCustomResourceDefinition(crd *apiextensionsv1beta1.CustomResourceD
 	return dynamicClient, nil
 }
 
-func checkForWatchCachePrimed(crd *apiextensionsv1beta1.CustomResourceDefinition, dynamicClient *dynamic.Client) error {
+func checkForWatchCachePrimed(crd *apiextensionsv1beta1.CustomResourceDefinition, dynamicClient dynamic.Interface) error {
 	ns := ""
 	if crd.Spec.Scope != apiextensionsv1beta1.ClusterScoped {
 		ns = "aval"

staging/src/k8s.io/client-go/dynamic/client.go

@@ -40,8 +40,42 @@ import (
 	"k8s.io/client-go/util/flowcontrol"
 )
 
-// Client is a Kubernetes client that allows you to access metadata
+// Interface is a Kubernetes client that allows you to access metadata
 // and manipulate metadata of a Kubernetes API group.
+type Interface interface {
+	// GetRateLimiter returns the rate limiter for this client.
+	GetRateLimiter() flowcontrol.RateLimiter
+	// Resource returns an API interface to the specified resource for this client's
+	// group and version.  If resource is not a namespaced resource, then namespace
+	// is ignored.  The ResourceInterface inherits the paramater codec of this client.
+	Resource(resource *metav1.APIResource, namespace string) ResourceInterface
+	// ParameterCodec returns a client with the provided parameter codec.
+	ParameterCodec(parameterCodec runtime.ParameterCodec) Interface
+}
+
+// ResourceInterface is an API interface to a specific resource under a
+// dynamic client.
+type ResourceInterface interface {
+	// List returns a list of objects for this resource.
+	List(opts metav1.ListOptions) (runtime.Object, error)
+	// Get gets the resource with the specified name.
+	Get(name string, opts metav1.GetOptions) (*unstructured.Unstructured, error)
+	// Delete deletes the resource with the specified name.
+	Delete(name string, opts *metav1.DeleteOptions) error
+	// DeleteCollection deletes a collection of objects.
+	DeleteCollection(deleteOptions *metav1.DeleteOptions, listOptions metav1.ListOptions) error
+	// Create creates the provided resource.
+	Create(obj *unstructured.Unstructured) (*unstructured.Unstructured, error)
+	// Update updates the provided resource.
+	Update(obj *unstructured.Unstructured) (*unstructured.Unstructured, error)
+	// Watch returns a watch.Interface that watches the resource.
+	Watch(opts metav1.ListOptions) (watch.Interface, error)
+	// Patch patches the provided resource.
+	Patch(name string, pt types.PatchType, data []byte) (*unstructured.Unstructured, error)
+}
+
+// Client is a Kubernetes client that allows you to access metadata
+// and manipulate metadata of a Kubernetes API group, and implements Interface.
 type Client struct {
 	cl             *restclient.RESTClient
 	parameterCodec runtime.ParameterCodec
@@ -84,8 +118,8 @@ func (c *Client) GetRateLimiter() flowcontrol.RateLimiter {
 
 // Resource returns an API interface to the specified resource for this client's
 // group and version. If resource is not a namespaced resource, then namespace
-// is ignored. The ResourceClient inherits the parameter codec of c.
+// is ignored. The ResourceInterface inherits the parameter codec of c.
-func (c *Client) Resource(resource *metav1.APIResource, namespace string) *ResourceClient {
+func (c *Client) Resource(resource *metav1.APIResource, namespace string) ResourceInterface {
 	return &ResourceClient{
 		cl:             c.cl,
 		resource:       resource,
@@ -95,7 +129,7 @@ func (c *Client) Resource(resource *metav1.APIResource, namespace string) *Resou
 }
 
 // ParameterCodec returns a client with the provided parameter codec.
-func (c *Client) ParameterCodec(parameterCodec runtime.ParameterCodec) *Client {
+func (c *Client) ParameterCodec(parameterCodec runtime.ParameterCodec) Interface {
 	return &Client{
 		cl:             c.cl,
 		parameterCodec: parameterCodec,
@@ -103,7 +137,7 @@ func (c *Client) ParameterCodec(parameterCodec runtime.ParameterCodec) *Client {
 }
 
 // ResourceClient is an API interface to a specific resource under a
-// dynamic client.
+// dynamic client, and implements ResourceInterface.
 type ResourceClient struct {
 	cl             *restclient.RESTClient
 	resource       *metav1.APIResource

staging/src/k8s.io/client-go/dynamic/client_pool.go

@@ -28,10 +28,10 @@ import (
 type ClientPool interface {
 	// ClientForGroupVersionKind returns a client configured for the specified groupVersionResource.
 	// Resource may be empty.
-	ClientForGroupVersionResource(resource schema.GroupVersionResource) (*Client, error)
+	ClientForGroupVersionResource(resource schema.GroupVersionResource) (Interface, error)
 	// ClientForGroupVersionKind returns a client configured for the specified groupVersionKind.
 	// Kind may be empty.
-	ClientForGroupVersionKind(kind schema.GroupVersionKind) (*Client, error)
+	ClientForGroupVersionKind(kind schema.GroupVersionKind) (Interface, error)
 }
 
 // APIPathResolverFunc knows how to convert a groupVersion to its API path. The Kind field is
@@ -79,7 +79,7 @@ func NewDynamicClientPool(cfg *restclient.Config) ClientPool {
 
 // ClientForGroupVersionResource uses the provided RESTMapper to identify the appropriate resource. Resource may
 // be empty. If no matching kind is found the underlying client for that group is still returned.
-func (c *clientPoolImpl) ClientForGroupVersionResource(resource schema.GroupVersionResource) (*Client, error) {
+func (c *clientPoolImpl) ClientForGroupVersionResource(resource schema.GroupVersionResource) (Interface, error) {
 	kinds, err := c.mapper.KindsFor(resource)
 	if err != nil {
 		if meta.IsNoMatchError(err) {
@@ -92,7 +92,7 @@ func (c *clientPoolImpl) ClientForGroupVersionResource(resource schema.GroupVers
 
 // ClientForGroupVersion returns a client for the specified groupVersion, creates one if none exists. Kind
 // in the GroupVersionKind may be empty.
-func (c *clientPoolImpl) ClientForGroupVersionKind(kind schema.GroupVersionKind) (*Client, error) {
+func (c *clientPoolImpl) ClientForGroupVersionKind(kind schema.GroupVersionKind) (Interface, error) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 

staging/src/k8s.io/client-go/dynamic/client_test.go

@@ -58,7 +58,7 @@ func getObject(version, kind, name string) *unstructured.Unstructured {
 	}
 }
 
-func getClientServer(gv *schema.GroupVersion, h func(http.ResponseWriter, *http.Request)) (*Client, *httptest.Server, error) {
+func getClientServer(gv *schema.GroupVersion, h func(http.ResponseWriter, *http.Request)) (Interface, *httptest.Server, error) {
 	srv := httptest.NewServer(http.HandlerFunc(h))
 	cl, err := NewClient(&restclient.Config{
 		Host:          srv.URL,

staging/src/k8s.io/client-go/dynamic/fake/BUILD

@@ -0,0 +1,29 @@
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "client.go",
+        "client_pool.go",
+    ],
+    tags = ["automanaged"],
+    deps = [
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1/unstructured:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/watch:go_default_library",
+        "//vendor/k8s.io/client-go/dynamic:go_default_library",
+        "//vendor/k8s.io/client-go/testing:go_default_library",
+        "//vendor/k8s.io/client-go/util/flowcontrol:go_default_library",
+    ],
+)

staging/src/k8s.io/client-go/dynamic/fake/client.go

@@ -0,0 +1,163 @@
+/*
+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 fake provides a fake client interface to arbitrary Kubernetes
+// APIs that exposes common high level operations and exposes common
+// metadata.
+package fake
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/testing"
+	"k8s.io/client-go/util/flowcontrol"
+)
+
+// FakeClient is a fake implementation of dynamic.Interface.
+type FakeClient struct {
+	GroupVersion schema.GroupVersion
+
+	*testing.Fake
+}
+
+// GetRateLimiter returns the rate limiter for this client.
+func (c *FakeClient) GetRateLimiter() flowcontrol.RateLimiter {
+	return nil
+}
+
+// Resource returns an API interface to the specified resource for this client's
+// group and version.  If resource is not a namespaced resource, then namespace
+// is ignored.  The ResourceClient inherits the paramater codec of this client
+func (c *FakeClient) Resource(resource *metav1.APIResource, namespace string) dynamic.ResourceInterface {
+	return &FakeResourceClient{
+		Resource:  c.GroupVersion.WithResource(resource.Name),
+		Kind:      c.GroupVersion.WithKind(resource.Kind),
+		Namespace: namespace,
+
+		Fake: c.Fake,
+	}
+}
+
+// ParameterCodec returns a client with the provided parameter codec.
+func (c *FakeClient) ParameterCodec(parameterCodec runtime.ParameterCodec) dynamic.Interface {
+	return &FakeClient{
+		Fake: c.Fake,
+	}
+}
+
+// FakeResourceClient is a fake implementation of dynamic.ResourceInterface
+type FakeResourceClient struct {
+	Resource  schema.GroupVersionResource
+	Kind      schema.GroupVersionKind
+	Namespace string
+
+	*testing.Fake
+}
+
+// List returns a list of objects for this resource.
+func (c *FakeResourceClient) List(opts metav1.ListOptions) (runtime.Object, error) {
+	obj, err := c.Fake.
+		Invokes(testing.NewListAction(c.Resource, c.Kind, c.Namespace, opts), &unstructured.UnstructuredList{})
+
+	if obj == nil {
+		return nil, err
+	}
+
+	label, _, _ := testing.ExtractFromListOptions(opts)
+	if label == nil {
+		label = labels.Everything()
+	}
+	list := &unstructured.UnstructuredList{}
+	for _, item := range obj.(*unstructured.UnstructuredList).Items {
+		if label.Matches(labels.Set(item.GetLabels())) {
+			list.Items = append(list.Items, item)
+		}
+	}
+	return list, err
+}
+
+// Get gets the resource with the specified name.
+func (c *FakeResourceClient) Get(name string, opts metav1.GetOptions) (*unstructured.Unstructured, error) {
+	obj, err := c.Fake.
+		Invokes(testing.NewGetAction(c.Resource, c.Namespace, name), &unstructured.Unstructured{})
+
+	if obj == nil {
+		return nil, err
+	}
+
+	return obj.(*unstructured.Unstructured), err
+}
+
+// Delete deletes the resource with the specified name.
+func (c *FakeResourceClient) Delete(name string, opts *metav1.DeleteOptions) error {
+	_, err := c.Fake.
+		Invokes(testing.NewDeleteAction(c.Resource, c.Namespace, name), &unstructured.Unstructured{})
+
+	return err
+}
+
+// DeleteCollection deletes a collection of objects.
+func (c *FakeResourceClient) DeleteCollection(deleteOptions *metav1.DeleteOptions, listOptions metav1.ListOptions) error {
+	_, err := c.Fake.
+		Invokes(testing.NewDeleteCollectionAction(c.Resource, c.Namespace, listOptions), &unstructured.Unstructured{})
+
+	return err
+}
+
+// Create creates the provided resource.
+func (c *FakeResourceClient) Create(inObj *unstructured.Unstructured) (*unstructured.Unstructured, error) {
+	obj, err := c.Fake.
+		Invokes(testing.NewCreateAction(c.Resource, c.Namespace, inObj), &unstructured.Unstructured{})
+
+	if obj == nil {
+		return nil, err
+	}
+	return obj.(*unstructured.Unstructured), err
+}
+
+// Update updates the provided resource.
+func (c *FakeResourceClient) Update(inObj *unstructured.Unstructured) (*unstructured.Unstructured, error) {
+	obj, err := c.Fake.
+		Invokes(testing.NewUpdateAction(c.Resource, c.Namespace, inObj), &unstructured.Unstructured{})
+
+	if obj == nil {
+		return nil, err
+	}
+	return obj.(*unstructured.Unstructured), err
+}
+
+// Watch returns a watch.Interface that watches the resource.
+func (c *FakeResourceClient) Watch(opts metav1.ListOptions) (watch.Interface, error) {
+	return c.Fake.
+		InvokesWatch(testing.NewWatchAction(c.Resource, c.Namespace, opts))
+}
+
+// Patch patches the provided resource.
+func (c *FakeResourceClient) Patch(name string, pt types.PatchType, data []byte) (*unstructured.Unstructured, error) {
+	obj, err := c.Fake.
+		Invokes(testing.NewPatchAction(c.Resource, c.Namespace, name, data), &unstructured.Unstructured{})
+
+	if obj == nil {
+		return nil, err
+	}
+	return obj.(*unstructured.Unstructured), err
+}

staging/src/k8s.io/client-go/dynamic/fake/client_pool.go

@@ -0,0 +1,48 @@
+/*
+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 fake provides a fake client interface to arbitrary Kubernetes
+// APIs that exposes common high level operations and exposes common
+// metadata.
+package fake
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/dynamic"
+	"k8s.io/client-go/testing"
+)
+
+// FakeClientPool provides a fake implementation of dynamic.ClientPool.
+// It assumes resource GroupVersions are the same as their corresponding kind GroupVersions.
+type FakeClientPool struct {
+	testing.Fake
+}
+
+// ClientForGroupVersionKind returns a client configured for the specified groupVersionResource.
+// Resource may be empty.
+func (p *FakeClientPool) ClientForGroupVersionResource(resource schema.GroupVersionResource) (dynamic.Interface, error) {
+	return p.ClientForGroupVersionKind(resource.GroupVersion().WithKind(""))
+}
+
+// ClientForGroupVersionKind returns a client configured for the specified groupVersionKind.
+// Kind may be empty.
+func (p *FakeClientPool) ClientForGroupVersionKind(kind schema.GroupVersionKind) (dynamic.Interface, error) {
+	// we can just create a new client every time for testing purposes
+	return &FakeClient{
+		GroupVersion: kind.GroupVersion(),
+		Fake:         &p.Fake,
+	}, nil
+}