Merge pull request #40770 from apilloud/clientset_interface

Automatic merge from submit-queue (batch tested with PRs 41103, 41042, 41097, 40946, 40770)

Use Clientset interface in KubeletDeps

**What this PR does / why we need it**:
This replaces the Clientset struct with the equivalent interface for the KubeClient injected via KubeletDeps. This is useful for testing and for accessing the Node and Pod status event stream without an API server.

**Special notes for your reviewer**:
Follow up to #4907

**Release note**:

`NONE`

cmd/kubelet/app/server.go

@@ -363,7 +363,7 @@ func run(s *options.KubeletServer, kubeDeps *kubelet.KubeletDeps) (err error) {
 	}
 
 	if kubeDeps == nil {
-		var kubeClient *clientset.Clientset
+		var kubeClient clientset.Interface
 		var eventClient v1core.EventsGetter
 		var externalKubeClient clientgoclientset.Interface
 		var cloud cloudprovider.Interface

pkg/kubelet/config/apiserver.go

@@ -29,7 +29,7 @@ import (
 )
 
 // NewSourceApiserver creates a config source that watches and pulls from the apiserver.
-func NewSourceApiserver(c *clientset.Clientset, nodeName types.NodeName, updates chan<- interface{}) {
+func NewSourceApiserver(c clientset.Interface, nodeName types.NodeName, updates chan<- interface{}) {
 	lw := cache.NewListWatchFromClient(c.Core().RESTClient(), "pods", metav1.NamespaceAll, fields.OneTermEqualSelector(api.PodHostField, string(nodeName)))
 	newSourceApiserverFromLW(lw, updates)
 }

pkg/kubelet/kubelet.go

@@ -220,7 +220,7 @@ type KubeletDeps struct {
 	ContainerManager   cm.ContainerManager
 	DockerClient       dockertools.DockerInterface
 	EventClient        v1core.EventsGetter
-	KubeClient         *clientset.Clientset
+	KubeClient         clientset.Interface
 	ExternalKubeClient clientgoclientset.Interface
 	Mounter            mount.Interface
 	NetworkPlugins     []network.NetworkPlugin
@@ -318,15 +318,6 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 		glog.V(2).Infof("cloud provider determined current node name to be %s", nodeName)
 	}
 
-	// TODO: KubeletDeps.KubeClient should be a client interface, but client interface misses certain methods
-	// used by kubelet. Since NewMainKubelet expects a client interface, we need to make sure we are not passing
-	// a nil pointer to it when what we really want is a nil interface.
-	var kubeClient clientset.Interface
-	if kubeDeps.KubeClient != nil {
-		kubeClient = kubeDeps.KubeClient
-		// TODO: remove this when we've refactored kubelet to only use clientset.
-	}
-
 	if kubeDeps.PodConfig == nil {
 		var err error
 		kubeDeps.PodConfig, err = makePodSourceConfig(kubeCfg, kubeDeps, nodeName)
@@ -384,16 +375,16 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 	}
 
 	serviceStore := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
-	if kubeClient != nil {
+	if kubeDeps.KubeClient != nil {
-		serviceLW := cache.NewListWatchFromClient(kubeClient.Core().RESTClient(), "services", metav1.NamespaceAll, fields.Everything())
+		serviceLW := cache.NewListWatchFromClient(kubeDeps.KubeClient.Core().RESTClient(), "services", metav1.NamespaceAll, fields.Everything())
 		cache.NewReflector(serviceLW, &v1.Service{}, serviceStore, 0).Run()
 	}
 	serviceLister := &listers.StoreToServiceLister{Indexer: serviceStore}
 
 	nodeStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
-	if kubeClient != nil {
+	if kubeDeps.KubeClient != nil {
 		fieldSelector := fields.Set{api.ObjectNameField: string(nodeName)}.AsSelector()
-		nodeLW := cache.NewListWatchFromClient(kubeClient.Core().RESTClient(), "nodes", metav1.NamespaceAll, fieldSelector)
+		nodeLW := cache.NewListWatchFromClient(kubeDeps.KubeClient.Core().RESTClient(), "nodes", metav1.NamespaceAll, fieldSelector)
 		cache.NewReflector(nodeLW, &v1.Node{}, nodeStore, 0).Run()
 	}
 	nodeLister := &listers.StoreToNodeLister{Store: nodeStore}
@@ -415,7 +406,7 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 	}
 	containerRefManager := kubecontainer.NewRefManager()
 
-	secretManager, err := secret.NewCachingSecretManager(kubeClient)
+	secretManager, err := secret.NewCachingSecretManager(kubeDeps.KubeClient)
 	if err != nil {
 		return nil, fmt.Errorf("failed to initialize secret manager: %v", err)
 	}
@@ -426,7 +417,7 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 		hostname:                       hostname,
 		nodeName:                       nodeName,
 		dockerClient:                   kubeDeps.DockerClient,
-		kubeClient:                     kubeClient,
+		kubeClient:                     kubeDeps.KubeClient,
 		rootDirectory:                  kubeCfg.RootDirectory,
 		resyncInterval:                 kubeCfg.SyncFrequency.Duration,
 		containerRefManager:            containerRefManager,
@@ -699,7 +690,7 @@ func NewMainKubelet(kubeCfg *componentconfig.KubeletConfiguration, kubeDeps *Kub
 	}
 	klet.imageManager = imageManager
 
-	klet.statusManager = status.NewManager(kubeClient, klet.podManager)
+	klet.statusManager = status.NewManager(klet.kubeClient, klet.podManager)
 
 	klet.probeManager = prober.NewManager(
 		klet.statusManager,