Kubelet: implement GetPodContainerID for new runtime API

pkg/kubelet/kuberuntime/kuberuntime_manager.go

@@ -404,7 +404,14 @@ func (m *kubeGenericRuntimeManager) GetNetNS(sandboxID kubecontainer.ContainerID
 
 // GetPodContainerID gets pod sandbox ID
 func (m *kubeGenericRuntimeManager) GetPodContainerID(pod *kubecontainer.Pod) (kubecontainer.ContainerID, error) {
-	return kubecontainer.ContainerID{}, fmt.Errorf("not implemented")
+	podFullName := kubecontainer.BuildPodFullName(pod.Name, pod.Namespace)
+	if len(pod.Sandboxes) == 0 {
+		glog.Errorf("No sandboxes are found for pod %q", podFullName)
+		return kubecontainer.ContainerID{}, fmt.Errorf("sandboxes for pod %q not found", podFullName)
+	}
+
+	// return sandboxID of the first sandbox since it is the latest one
+	return pod.Sandboxes[0].ID, nil
 }
 
 // Forward the specified port from the specified pod to the stream.

pkg/kubelet/kuberuntime/kuberuntime_manager_test.go

@@ -289,6 +289,54 @@ func TestGetPods(t *testing.T) {
 	}
 }
 
+func TestGetPodContainerID(t *testing.T) {
+	fakeRuntime, _, m, err := createTestRuntimeManager()
+	assert.NoError(t, err)
+
+	pod := &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			UID:       "12345678",
+			Name:      "foo",
+			Namespace: "new",
+		},
+		Spec: api.PodSpec{
+			Containers: []api.Container{
+				{
+					Name:  "foo1",
+					Image: "busybox",
+				},
+				{
+					Name:  "foo2",
+					Image: "busybox",
+				},
+			},
+		},
+	}
+	// Set fake sandbox and fake containers to fakeRuntime.
+	fakeSandbox, _, err := makeAndSetFakePod(m, fakeRuntime, pod)
+	assert.NoError(t, err)
+
+	// Convert fakeSandbox to kubecontainer.Container
+	sandbox, err := m.sandboxToKubeContainer(&runtimeApi.PodSandbox{
+		Id:        fakeSandbox.Id,
+		Metadata:  fakeSandbox.Metadata,
+		State:     fakeSandbox.State,
+		CreatedAt: fakeSandbox.CreatedAt,
+		Labels:    fakeSandbox.Labels,
+	})
+	assert.NoError(t, err)
+
+	expectedPod := &kubecontainer.Pod{
+		ID:         pod.UID,
+		Name:       pod.Name,
+		Namespace:  pod.Namespace,
+		Containers: []*kubecontainer.Container{},
+		Sandboxes:  []*kubecontainer.Container{sandbox},
+	}
+	actual, err := m.GetPodContainerID(expectedPod)
+	assert.Equal(t, fakeSandbox.GetId(), actual.ID)
+}
+
 func TestGetNetNS(t *testing.T) {
 	fakeRuntime, _, m, err := createTestRuntimeManager()
 	assert.NoError(t, err)