Merge pull request #4907 from ddysher/kubelet-client-interface

kubelet should take a client interface

cmd/kubelet/app/server.go

@@ -389,12 +389,20 @@ type KubeletConfig struct {
 func createAndInitKubelet(kc *KubeletConfig, pc *config.PodConfig) (*kubelet.Kubelet, error) {
 	// TODO: block until all sources have delivered at least one update to the channel, or break the sync loop
 	// up into "per source" synchronizations
-
+	// TODO: KubeletConfig.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 client.Interface
+	if kc.KubeClient == nil {
+		kubeClient = nil
+	} else {
+		kubeClient = kc.KubeClient
+	}
 	k, err := kubelet.NewMainKubelet(
 		kc.Hostname,
 		kc.DockerClient,
 		kc.EtcdClient,
-		kc.KubeClient,
+		kubeClient,
 		kc.RootDirectory,
 		kc.PodInfraContainerImage,
 		kc.SyncFrequency,

pkg/client/cache/listwatch.go

@@ -37,7 +37,7 @@ type ListWatch struct {
 	WatchFunc WatchFunc
 }
 
-// ListWatchFromClient creates a new ListWatch from the specified client, resource, namespace and field selector
+// NewListWatchFromClient creates a new ListWatch from the specified client, resource, namespace and field selector.
 func NewListWatchFromClient(client *client.Client, resource string, namespace string, fieldSelector labels.Selector) *ListWatch {
 	listFunc := func() (runtime.Object, error) {
 		return client.Get().Namespace(namespace).Resource(resource).SelectorParam("fields", fieldSelector).Do().Get()

pkg/kubelet/kubelet.go

@@ -42,10 +42,12 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/volume"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/probe"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/errors"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 	"github.com/fsouza/go-dockerclient"
 	"github.com/golang/glog"
 )
@@ -76,7 +78,7 @@ func NewMainKubelet(
 	hostname string,
 	dockerClient dockertools.DockerInterface,
 	etcdClient tools.EtcdClient,
-	kubeClient *client.Client,
+	kubeClient client.Interface,
 	rootDirectory string,
 	podInfraContainerImage string,
 	resyncInterval time.Duration,
@@ -103,12 +105,17 @@ func NewMainKubelet(
 
 	serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
 	if kubeClient != nil {
-		cache.NewReflector(
-			cache.NewListWatchFromClient(kubeClient, "services", api.NamespaceAll, labels.Everything()),
-			&api.Service{},
-			serviceStore,
-			0,
-		).Run()
+		// TODO: cache.NewListWatchFromClient is limited as it takes a client implementation rather
+		// than an interface. There is no way to construct a list+watcher using resource name.
+		listWatch := &cache.ListWatch{
+			ListFunc: func() (runtime.Object, error) {
+				return kubeClient.Services(api.NamespaceAll).List(labels.Everything())
+			},
+			WatchFunc: func(resourceVersion string) (watch.Interface, error) {
+				return kubeClient.Services(api.NamespaceAll).Watch(labels.Everything(), labels.Everything(), resourceVersion)
+			},
+		}
+		cache.NewReflector(listWatch, &api.Service{}, serviceStore, 0).Run()
 	}
 	serviceLister := &cache.StoreToServiceLister{serviceStore}
 
@@ -173,7 +180,7 @@ type Kubelet struct {
 	hostname               string
 	dockerClient           dockertools.DockerInterface
 	dockerCache            dockertools.DockerCache
-	kubeClient             *client.Client
+	kubeClient             client.Interface
 	rootDirectory          string
 	podInfraContainerImage string
 	podWorkers             *podWorkers