Add a kubelet /runningpods endpoint

/runningpods returns a list of pods currently running on the kubelet. The list
is composed by examining the container runtime, and may be different from the
desired pods to run known by kubelet.

This is useful for tests to verify that pods are indeed deleted on nodes.

pkg/kubelet/server_test.go

@@ -47,6 +47,7 @@ type fakeKubelet struct {
 	rawInfoFunc                        func(query *cadvisorApi.ContainerInfoRequest) (map[string]*cadvisorApi.ContainerInfo, error)
 	machineInfoFunc                    func() (*cadvisorApi.MachineInfo, error)
 	podsFunc                           func() []*api.Pod
+	runningPodsFunc                    func() ([]*api.Pod, error)
 	logFunc                            func(w http.ResponseWriter, req *http.Request)
 	runFunc                            func(podFullName string, uid types.UID, containerName string, cmd []string) ([]byte, error)
 	containerVersionFunc               func() (kubecontainer.Version, error)
@@ -91,6 +92,10 @@ func (fk *fakeKubelet) GetPods() []*api.Pod {
 	return fk.podsFunc()
 }
 
+func (fk *fakeKubelet) GetRunningPods() ([]*api.Pod, error) {
+	return fk.runningPodsFunc()
+}
+
 func (fk *fakeKubelet) ServeLogs(w http.ResponseWriter, req *http.Request) {
 	fk.logFunc(w, req)
 }