Add Status in runtime interface and use it for runtime health check.

pkg/kubelet/container/runtime.go

@@ -57,7 +57,10 @@ type Runtime interface {
 	Version() (Version, error)
 	// APIVersion returns the API version information of the container
 	// runtime. This may be different from the runtime engine's version.
+	// TODO(random-liu): We should fold this into Version()
 	APIVersion() (Version, error)
+	// Status returns error if the runtime is unhealthy; nil otherwise.
+	Status() error
 	// GetPods returns a list containers group by pods. The boolean parameter
 	// specifies whether the runtime returns all containers including those already
 	// exited and dead containers (used for garbage collection).

pkg/kubelet/container/testing/fake_runtime.go

@@ -48,6 +48,7 @@ type FakeRuntime struct {
 	RuntimeType       string
 	Err               error
 	InspectErr        error
+	StatusErr         error
 }
 
 // FakeRuntime should implement Runtime.
@@ -108,6 +109,7 @@ func (f *FakeRuntime) ClearCalls() {
 	f.RuntimeType = ""
 	f.Err = nil
 	f.InspectErr = nil
+	f.StatusErr = nil
 }
 
 func (f *FakeRuntime) assertList(expect []string, test []string) error {
@@ -168,6 +170,14 @@ func (f *FakeRuntime) APIVersion() (Version, error) {
 	return &FakeVersion{Version: f.APIVersionInfo}, f.Err
 }
 
+func (f *FakeRuntime) Status() error {
+	f.Lock()
+	defer f.Unlock()
+
+	f.CalledFunctions = append(f.CalledFunctions, "Status")
+	return f.StatusErr
+}
+
 func (f *FakeRuntime) GetPods(all bool) ([]*Pod, error) {
 	f.Lock()
 	defer f.Unlock()

pkg/kubelet/container/testing/runtime_mock.go

@@ -53,6 +53,11 @@ func (r *Mock) APIVersion() (Version, error) {
 	return args.Get(0).(Version), args.Error(1)
 }
 
+func (r *Mock) Status() error {
+	args := r.Called()
+	return args.Error(0)
+}
+
 func (r *Mock) GetPods(all bool) ([]*Pod, error) {
 	args := r.Called(all)
 	return args.Get(0).([]*Pod), args.Error(1)

pkg/kubelet/dockertools/fake_docker_client.go

@@ -68,6 +68,26 @@ func NewFakeDockerClientWithVersion(version, apiVersion string) *FakeDockerClien
 	}
 }
 
+func (f *FakeDockerClient) InjectError(fn string, err error) {
+	f.Lock()
+	defer f.Unlock()
+	f.Errors[fn] = err
+}
+
+func (f *FakeDockerClient) InjectErrors(errs map[string]error) {
+	f.Lock()
+	defer f.Unlock()
+	for fn, err := range errs {
+		f.Errors[fn] = err
+	}
+}
+
+func (f *FakeDockerClient) ClearErrors() {
+	f.Lock()
+	defer f.Unlock()
+	f.Errors = map[string]error{}
+}
+
 func (f *FakeDockerClient) ClearCalls() {
 	f.Lock()
 	defer f.Unlock()
@@ -382,7 +402,7 @@ func (f *FakeDockerClient) PullImage(opts docker.PullImageOptions, auth docker.A
 }
 
 func (f *FakeDockerClient) Version() (*docker.Env, error) {
-	return &f.VersionInfo, nil
+	return &f.VersionInfo, f.popError("version")
 }
 
 func (f *FakeDockerClient) Info() (*docker.Env, error) {

pkg/kubelet/dockertools/manager.go

@@ -60,7 +60,7 @@ import (
 const (
 	DockerType = "docker"
 
-	MinimumDockerAPIVersion = "1.18"
+	minimumDockerAPIVersion = "1.18"
 
 	// ndots specifies the minimum number of dots that a domain name must contain for the resolver to consider it as FQDN (fully-qualified)
 	// we want to able to consider SRV lookup names like _dns._udp.kube-dns.default.svc to be considered relative.
@@ -941,6 +941,30 @@ func (dm *DockerManager) APIVersion() (kubecontainer.Version, error) {
 	return dockerAPIVersion(version), nil
 }
 
+// Status returns error if docker daemon is unhealthy, nil otherwise.
+// Now we do this by checking whether:
+// 1) `docker version` works
+// 2) docker version is compatible with minimum requirement
+func (dm *DockerManager) Status() error {
+	return dm.checkVersionCompatibility()
+}
+
+func (dm *DockerManager) checkVersionCompatibility() error {
+	version, err := dm.APIVersion()
+	if err != nil {
+		return err
+	}
+	// Verify the docker version.
+	result, err := version.Compare(minimumDockerAPIVersion)
+	if err != nil {
+		return fmt.Errorf("failed to compare current docker version %v with minimum support Docker version %q - %v", version, minimumDockerAPIVersion, err)
+	}
+	if result < 0 {
+		return fmt.Errorf("container runtime version is older than %s", minimumDockerAPIVersion)
+	}
+	return nil
+}
+
 // The first version of docker that supports exec natively is 1.3.0 == API 1.15
 var dockerAPIVersionWithExec = "1.15"
 

pkg/kubelet/dockertools/manager_test.go

@@ -546,7 +546,7 @@ func TestKillContainerInPodWithError(t *testing.T) {
 		},
 	}
 	fakeDocker.SetFakeRunningContainers(containers)
-	fakeDocker.Errors["stop"] = fmt.Errorf("sample error")
+	fakeDocker.InjectError("stop", fmt.Errorf("sample error"))
 
 	if err := manager.KillContainerInPod(kubecontainer.ContainerID{}, &pod.Spec.Containers[0], pod, "test kill container with error."); err == nil {
 		t.Errorf("expected error, found nil")
@@ -1744,7 +1744,7 @@ func TestSyncPodWithFailure(t *testing.T) {
 			ID:   "9876",
 			Name: "/k8s_POD." + strconv.FormatUint(generatePodInfraContainerHash(pod), 16) + "_foo_new_12345678_0",
 		}})
-		fakeDocker.Errors = test.dockerError
+		fakeDocker.InjectErrors(test.dockerError)
 		puller.ErrorsToInject = test.pullerError
 		pod.Spec.Containers = []api.Container{test.container}
 		result := runSyncPod(t, dm, fakeDocker, pod, nil, true)
@@ -1865,3 +1865,44 @@ func TestSecurityOptsAreNilWithDockerV19(t *testing.T) {
 	}
 	assert.NotContains(t, newContainer.HostConfig.SecurityOpt, "seccomp:unconfined", "Pods with Docker versions < 1.10 must not have seccomp disabled by default")
 }
+
+func TestCheckVersionCompatibility(t *testing.T) {
+	apiVersion, err := docker.NewAPIVersion(minimumDockerAPIVersion)
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	type test struct {
+		version    string
+		compatible bool
+	}
+	tests := []test{
+		// Minimum apiversion
+		{minimumDockerAPIVersion, true},
+		// Invalid apiversion
+		{"invalid_api_version", false},
+	}
+	for i := range apiVersion {
+		apiVersion[i]++
+		// Newer apiversion
+		tests = append(tests, test{apiVersion.String(), true})
+		apiVersion[i] -= 2
+		// Older apiversion
+		if apiVersion[i] >= 0 {
+			tests = append(tests, test{apiVersion.String(), false})
+		}
+		apiVersion[i]++
+	}
+
+	for i, tt := range tests {
+		testCase := fmt.Sprintf("test case #%d test version %q", i, tt.version)
+		dm, fakeDocker := newTestDockerManagerWithHTTPClientWithVersion(&fakeHTTP{}, "", tt.version)
+		err := dm.checkVersionCompatibility()
+		assert.Equal(t, tt.compatible, err == nil, testCase)
+		if tt.compatible == true {
+			// Get docker version error
+			fakeDocker.InjectError("version", fmt.Errorf("injected version error"))
+			err := dm.checkVersionCompatibility()
+			assert.NotNil(t, err, testCase+" version error check")
+		}
+	}
+}

pkg/kubelet/kubelet.go

@@ -457,7 +457,7 @@ func NewMainKubelet(
 	}
 
 	klet.pleg = pleg.NewGenericPLEG(klet.containerRuntime, plegChannelCapacity, plegRelistPeriod, klet.podCache, util.RealClock{})
-	klet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, configureCBR0, klet.isContainerRuntimeVersionCompatible)
+	klet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, configureCBR0)
 	klet.updatePodCIDR(podCIDR)
 
 	// setup containerGC
@@ -2659,7 +2659,7 @@ func (kl *Kubelet) GetPodByName(namespace, name string) (*api.Pod, bool) {
 }
 
 func (kl *Kubelet) updateRuntimeUp() {
-	if _, err := kl.containerRuntime.Version(); err != nil {
+	if err := kl.containerRuntime.Status(); err != nil {
 		glog.Errorf("Container runtime sanity check failed: %v", err)
 		return
 	}
@@ -3076,26 +3076,6 @@ func SetNodeStatus(f func(*api.Node) error) Option {
 	}
 }
 
-// FIXME: Why not combine this with container runtime health check?
-func (kl *Kubelet) isContainerRuntimeVersionCompatible() error {
-	switch kl.GetRuntime().Type() {
-	case "docker":
-		version, err := kl.GetRuntime().APIVersion()
-		if err != nil {
-			return nil
-		}
-		// Verify the docker version.
-		result, err := version.Compare(dockertools.MinimumDockerAPIVersion)
-		if err != nil {
-			return fmt.Errorf("failed to compare current docker version %v with minimum support Docker version %q - %v", version, dockertools.MinimumDockerAPIVersion, err)
-		}
-		if result < 0 {
-			return fmt.Errorf("container runtime version is older than %s", dockertools.MinimumDockerAPIVersion)
-		}
-	}
-	return nil
-}
-
 // tryUpdateNodeStatus tries to update node status to master. If ReconcileCBR0
 // is set, this function will also confirm that cbr0 is configured correctly.
 func (kl *Kubelet) tryUpdateNodeStatus() error {

pkg/kubelet/kubelet_test.go

@@ -102,7 +102,8 @@ type TestKubelet struct {
 
 func newTestKubelet(t *testing.T) *TestKubelet {
 	fakeRuntime := &containertest.FakeRuntime{}
-	fakeRuntime.VersionInfo = "1.15"
+	fakeRuntime.RuntimeType = "test"
+	fakeRuntime.VersionInfo = "1.5.0"
 	fakeRuntime.ImageList = []kubecontainer.Image{
 		{
 			ID:       "abc",
@@ -123,7 +124,7 @@ func newTestKubelet(t *testing.T) *TestKubelet {
 
 	kubelet.hostname = testKubeletHostname
 	kubelet.nodeName = testKubeletHostname
-	kubelet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, false, func() error { return nil })
+	kubelet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, false)
 	kubelet.networkPlugin, _ = network.InitNetworkPlugin([]network.NetworkPlugin{}, "", nettest.NewFakeHost(nil))
 	if tempDir, err := ioutil.TempDir("/tmp", "kubelet_test."); err != nil {
 		t.Fatalf("can't make a temp rootdir: %v", err)
@@ -2654,9 +2655,6 @@ func updateDiskSpacePolicy(kubelet *Kubelet, mockCadvisor *cadvisortest.Mock, ro
 func TestUpdateNewNodeStatus(t *testing.T) {
 	testKubelet := newTestKubelet(t)
 	kubelet := testKubelet.kubelet
-	fakeRuntime := testKubelet.fakeRuntime
-	fakeRuntime.RuntimeType = "docker"
-	fakeRuntime.VersionInfo = "1.5.0"
 	kubeClient := testKubelet.fakeKubeClient
 	kubeClient.ReactionChain = fake.NewSimpleClientset(&api.NodeList{Items: []api.Node{
 		{ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}},
@@ -2710,7 +2708,7 @@ func TestUpdateNewNodeStatus(t *testing.T) {
 				BootID:                  "1b3",
 				KernelVersion:           "3.16.0-0.bpo.4-amd64",
 				OSImage:                 "Debian GNU/Linux 7 (wheezy)",
-				ContainerRuntimeVersion: "docker://1.5.0",
+				ContainerRuntimeVersion: "test://1.5.0",
 				KubeletVersion:          version.Get().String(),
 				KubeProxyVersion:        version.Get().String(),
 			},
@@ -2852,197 +2850,9 @@ func TestUpdateNewNodeOutOfDiskStatusWithTransitionFrequency(t *testing.T) {
 	}
 }
 
-func TestDockerRuntimeVersion(t *testing.T) {
-	testKubelet := newTestKubelet(t)
-	kubelet := testKubelet.kubelet
-	fakeRuntime := testKubelet.fakeRuntime
-	fakeRuntime.RuntimeType = "docker"
-	fakeRuntime.VersionInfo = "1.10.0-rc1-fc24"
-	fakeRuntime.APIVersionInfo = "1.22"
-	kubeClient := testKubelet.fakeKubeClient
-	kubeClient.ReactionChain = fake.NewSimpleClientset(&api.NodeList{Items: []api.Node{
-		{
-			ObjectMeta: api.ObjectMeta{Name: testKubeletHostname},
-			Spec:       api.NodeSpec{},
-			Status: api.NodeStatus{
-				Conditions: []api.NodeCondition{
-					{
-						Type:               api.NodeOutOfDisk,
-						Status:             api.ConditionFalse,
-						Reason:             "KubeletHasSufficientDisk",
-						Message:            fmt.Sprintf("kubelet has sufficient disk space available"),
-						LastHeartbeatTime:  unversioned.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
-						LastTransitionTime: unversioned.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
-					},
-					{
-						Type:               api.NodeReady,
-						Status:             api.ConditionTrue,
-						Reason:             "KubeletReady",
-						Message:            fmt.Sprintf("kubelet is posting ready status"),
-						LastHeartbeatTime:  unversioned.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
-						LastTransitionTime: unversioned.Date(2012, 1, 1, 0, 0, 0, 0, time.UTC),
-					},
-				},
-				Capacity: api.ResourceList{
-					api.ResourceCPU:    *resource.NewMilliQuantity(3000, resource.DecimalSI),
-					api.ResourceMemory: *resource.NewQuantity(20E9, resource.BinarySI),
-					api.ResourcePods:   *resource.NewQuantity(0, resource.DecimalSI),
-				},
-				Allocatable: api.ResourceList{
-					api.ResourceCPU:    *resource.NewMilliQuantity(2800, resource.DecimalSI),
-					api.ResourceMemory: *resource.NewQuantity(19900E6, resource.BinarySI),
-					api.ResourcePods:   *resource.NewQuantity(0, resource.DecimalSI),
-				},
-			},
-		},
-	}}).ReactionChain
-	mockCadvisor := testKubelet.fakeCadvisor
-	mockCadvisor.On("Start").Return(nil)
-	machineInfo := &cadvisorapi.MachineInfo{
-		MachineID:      "123",
-		SystemUUID:     "abc",
-		BootID:         "1b3",
-		NumCores:       2,
-		MemoryCapacity: 20E9,
-	}
-	mockCadvisor.On("MachineInfo").Return(machineInfo, nil)
-	versionInfo := &cadvisorapi.VersionInfo{
-		KernelVersion:      "3.16.0-0.bpo.4-amd64",
-		ContainerOsVersion: "Debian GNU/Linux 7 (wheezy)",
-	}
-	mockCadvisor.On("VersionInfo").Return(versionInfo, nil)
-
-	// Make kubelet report that it has sufficient disk space.
-	if err := updateDiskSpacePolicy(kubelet, mockCadvisor, 500, 500, 200, 200, 100, 100); err != nil {
-		t.Fatalf("can't update disk space manager: %v", err)
-	}
-
-	expectedNode := &api.Node{
-		ObjectMeta: api.ObjectMeta{Name: testKubeletHostname},
-		Spec:       api.NodeSpec{},
-		Status: api.NodeStatus{
-			Conditions: []api.NodeCondition{
-				{
-					Type:               api.NodeOutOfDisk,
-					Status:             api.ConditionFalse,
-					Reason:             "KubeletHasSufficientDisk",
-					Message:            fmt.Sprintf("kubelet has sufficient disk space available"),
-					LastHeartbeatTime:  unversioned.Time{},
-					LastTransitionTime: unversioned.Time{},
-				},
-				{
-					Type:               api.NodeReady,
-					Status:             api.ConditionTrue,
-					Reason:             "KubeletReady",
-					Message:            fmt.Sprintf("kubelet is posting ready status"),
-					LastHeartbeatTime:  unversioned.Time{},
-					LastTransitionTime: unversioned.Time{},
-				},
-			},
-			NodeInfo: api.NodeSystemInfo{
-				MachineID:               "123",
-				SystemUUID:              "abc",
-				BootID:                  "1b3",
-				KernelVersion:           "3.16.0-0.bpo.4-amd64",
-				OSImage:                 "Debian GNU/Linux 7 (wheezy)",
-				ContainerRuntimeVersion: "docker://1.10.0-rc1-fc24",
-				KubeletVersion:          version.Get().String(),
-				KubeProxyVersion:        version.Get().String(),
-			},
-			Capacity: api.ResourceList{
-				api.ResourceCPU:    *resource.NewMilliQuantity(2000, resource.DecimalSI),
-				api.ResourceMemory: *resource.NewQuantity(20E9, resource.BinarySI),
-				api.ResourcePods:   *resource.NewQuantity(0, resource.DecimalSI),
-			},
-			Allocatable: api.ResourceList{
-				api.ResourceCPU:    *resource.NewMilliQuantity(1800, resource.DecimalSI),
-				api.ResourceMemory: *resource.NewQuantity(19900E6, resource.BinarySI),
-				api.ResourcePods:   *resource.NewQuantity(0, resource.DecimalSI),
-			},
-			Addresses: []api.NodeAddress{
-				{Type: api.NodeLegacyHostIP, Address: "127.0.0.1"},
-				{Type: api.NodeInternalIP, Address: "127.0.0.1"},
-			},
-			Images: []api.ContainerImage{
-				{
-					Names:     []string{"gcr.io/google_containers:v1", "gcr.io/google_containers:v2"},
-					SizeBytes: 123,
-				},
-				{
-					Names:     []string{"gcr.io/google_containers:v3", "gcr.io/google_containers:v4"},
-					SizeBytes: 456,
-				},
-			},
-		},
-	}
-
-	kubelet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, false, kubelet.isContainerRuntimeVersionCompatible)
-	kubelet.updateRuntimeUp()
-	if err := kubelet.updateNodeStatus(); err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-	actions := kubeClient.Actions()
-	if len(actions) != 2 {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	if !actions[1].Matches("update", "nodes") || actions[1].GetSubresource() != "status" {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	updatedNode, ok := actions[1].(testclient.UpdateAction).GetObject().(*api.Node)
-	if !ok {
-		t.Errorf("unexpected object type")
-	}
-	for i, cond := range updatedNode.Status.Conditions {
-		if cond.LastHeartbeatTime.IsZero() {
-			t.Errorf("unexpected zero last probe timestamp")
-		}
-		if cond.LastTransitionTime.IsZero() {
-			t.Errorf("unexpected zero last transition timestamp")
-		}
-		updatedNode.Status.Conditions[i].LastHeartbeatTime = unversioned.Time{}
-		updatedNode.Status.Conditions[i].LastTransitionTime = unversioned.Time{}
-	}
-
-	// Version skew workaround. See: https://github.com/kubernetes/kubernetes/issues/16961
-	if updatedNode.Status.Conditions[len(updatedNode.Status.Conditions)-1].Type != api.NodeReady {
-		t.Errorf("unexpected node condition order. NodeReady should be last.")
-	}
-
-	if !api.Semantic.DeepEqual(expectedNode, updatedNode) {
-		t.Errorf("expected \n%v\n, got \n%v", expectedNode, updatedNode)
-	}
-
-	// Downgrade docker version, node should be NotReady
-	fakeRuntime.RuntimeType = "docker"
-	fakeRuntime.VersionInfo = "1.5.0"
-	fakeRuntime.APIVersionInfo = "1.17"
-	kubelet.updateRuntimeUp()
-	if err := kubelet.updateNodeStatus(); err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-	actions = kubeClient.Actions()
-	if len(actions) != 4 {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	if !actions[1].Matches("update", "nodes") || actions[1].GetSubresource() != "status" {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	updatedNode, ok = actions[3].(testclient.UpdateAction).GetObject().(*api.Node)
-	if !ok {
-		t.Errorf("unexpected object type")
-	}
-	if updatedNode.Status.Conditions[1].Reason != "KubeletNotReady" &&
-		!strings.Contains(updatedNode.Status.Conditions[1].Message, "container runtime version is older than") {
-		t.Errorf("unexpect NodeStatus due to container runtime version")
-	}
-}
-
 func TestUpdateExistingNodeStatus(t *testing.T) {
 	testKubelet := newTestKubelet(t)
 	kubelet := testKubelet.kubelet
-	fakeRuntime := testKubelet.fakeRuntime
-	fakeRuntime.RuntimeType = "docker"
-	fakeRuntime.VersionInfo = "1.5.0"
 	kubeClient := testKubelet.fakeKubeClient
 	kubeClient.ReactionChain = fake.NewSimpleClientset(&api.NodeList{Items: []api.Node{
 		{
@@ -3129,7 +2939,7 @@ func TestUpdateExistingNodeStatus(t *testing.T) {
 				BootID:                  "1b3",
 				KernelVersion:           "3.16.0-0.bpo.4-amd64",
 				OSImage:                 "Debian GNU/Linux 7 (wheezy)",
-				ContainerRuntimeVersion: "docker://1.5.0",
+				ContainerRuntimeVersion: "test://1.5.0",
 				KubeletVersion:          version.Get().String(),
 				KubeProxyVersion:        version.Get().String(),
 			},
@@ -3350,13 +3160,11 @@ func TestUpdateExistingNodeOutOfDiskStatusWithTransitionFrequency(t *testing.T)
 	}
 }
 
-func TestUpdateNodeStatusWithoutContainerRuntime(t *testing.T) {
+func TestUpdateNodeStatusWithRuntimeStateError(t *testing.T) {
 	testKubelet := newTestKubelet(t)
 	kubelet := testKubelet.kubelet
+	clock := testKubelet.fakeClock
 	kubeClient := testKubelet.fakeKubeClient
-	fakeRuntime := testKubelet.fakeRuntime
-	fakeRuntime.RuntimeType = "docker"
-	fakeRuntime.VersionInfo = "1.5.0"
 	kubeClient.ReactionChain = fake.NewSimpleClientset(&api.NodeList{Items: []api.Node{
 		{ObjectMeta: api.ObjectMeta{Name: testKubeletHostname}},
 	}}).ReactionChain
@@ -3394,14 +3202,7 @@ func TestUpdateNodeStatusWithoutContainerRuntime(t *testing.T) {
 					LastHeartbeatTime:  unversioned.Time{},
 					LastTransitionTime: unversioned.Time{},
 				},
-				{
-					Type:               api.NodeReady,
-					Status:             api.ConditionFalse,
-					Reason:             "KubeletNotReady",
-					Message:            fmt.Sprintf("container runtime is down"),
-					LastHeartbeatTime:  unversioned.Time{},
-					LastTransitionTime: unversioned.Time{},
-				},
+				{}, //placeholder
 			},
 			NodeInfo: api.NodeSystemInfo{
 				MachineID:               "123",
@@ -3409,7 +3210,7 @@ func TestUpdateNodeStatusWithoutContainerRuntime(t *testing.T) {
 				BootID:                  "1b3",
 				KernelVersion:           "3.16.0-0.bpo.4-amd64",
 				OSImage:                 "Debian GNU/Linux 7 (wheezy)",
-				ContainerRuntimeVersion: "docker://1.5.0",
+				ContainerRuntimeVersion: "test://1.5.0",
 				KubeletVersion:          version.Get().String(),
 				KubeProxyVersion:        version.Get().String(),
 			},
@@ -3439,42 +3240,77 @@ func TestUpdateNodeStatusWithoutContainerRuntime(t *testing.T) {
 			},
 		},
 	}
-	kubelet.runtimeState = newRuntimeState(time.Duration(0), false, func() error { return nil })
+
+	checkNodeStatus := func(status api.ConditionStatus, reason, message string) {
+		kubeClient.ClearActions()
+		if err := kubelet.updateNodeStatus(); err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		actions := kubeClient.Actions()
+		if len(actions) != 2 {
+			t.Fatalf("unexpected actions: %v", actions)
+		}
+		if !actions[1].Matches("update", "nodes") || actions[1].GetSubresource() != "status" {
+			t.Fatalf("unexpected actions: %v", actions)
+		}
+		updatedNode, ok := actions[1].(testclient.UpdateAction).GetObject().(*api.Node)
+		if !ok {
+			t.Errorf("unexpected action type.  expected UpdateAction, got %#v", actions[1])
+		}
+
+		for i, cond := range updatedNode.Status.Conditions {
+			if cond.LastHeartbeatTime.IsZero() {
+				t.Errorf("unexpected zero last probe timestamp")
+			}
+			if cond.LastTransitionTime.IsZero() {
+				t.Errorf("unexpected zero last transition timestamp")
+			}
+			updatedNode.Status.Conditions[i].LastHeartbeatTime = unversioned.Time{}
+			updatedNode.Status.Conditions[i].LastTransitionTime = unversioned.Time{}
+		}
+
+		// Version skew workaround. See: https://github.com/kubernetes/kubernetes/issues/16961
+		if updatedNode.Status.Conditions[len(updatedNode.Status.Conditions)-1].Type != api.NodeReady {
+			t.Errorf("unexpected node condition order. NodeReady should be last.")
+		}
+		expectedNode.Status.Conditions[1] = api.NodeCondition{
+			Type:               api.NodeReady,
+			Status:             status,
+			Reason:             reason,
+			Message:            message,
+			LastHeartbeatTime:  unversioned.Time{},
+			LastTransitionTime: unversioned.Time{},
+		}
+		if !api.Semantic.DeepEqual(expectedNode, updatedNode) {
+			t.Errorf("unexpected objects: %s", util.ObjectDiff(expectedNode, updatedNode))
+		}
+	}
+
+	readyMessage := "kubelet is posting ready status"
+	downMessage := "container runtime is down"
+
+	// Should report kubelet not ready if the runtime check is out of date
+	clock.SetTime(time.Now().Add(-maxWaitForContainerRuntime))
 	kubelet.updateRuntimeUp()
-	if err := kubelet.updateNodeStatus(); err != nil {
-		t.Errorf("unexpected error: %v", err)
-	}
-	actions := kubeClient.Actions()
-	if len(actions) != 2 {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	if !actions[1].Matches("update", "nodes") || actions[1].GetSubresource() != "status" {
-		t.Fatalf("unexpected actions: %v", actions)
-	}
-	updatedNode, ok := actions[1].(testclient.UpdateAction).GetObject().(*api.Node)
-	if !ok {
-		t.Errorf("unexpected action type.  expected UpdateAction, got %#v", actions[1])
-	}
+	checkNodeStatus(api.ConditionFalse, "KubeletNotReady", downMessage)
 
-	for i, cond := range updatedNode.Status.Conditions {
-		if cond.LastHeartbeatTime.IsZero() {
-			t.Errorf("unexpected zero last probe timestamp")
-		}
-		if cond.LastTransitionTime.IsZero() {
-			t.Errorf("unexpected zero last transition timestamp")
-		}
-		updatedNode.Status.Conditions[i].LastHeartbeatTime = unversioned.Time{}
-		updatedNode.Status.Conditions[i].LastTransitionTime = unversioned.Time{}
-	}
+	// Should report kubelet ready if the runtime check is updated
+	clock.SetTime(time.Now())
+	kubelet.updateRuntimeUp()
+	checkNodeStatus(api.ConditionTrue, "KubeletReady", readyMessage)
 
-	// Version skew workaround. See: https://github.com/kubernetes/kubernetes/issues/16961
-	if updatedNode.Status.Conditions[len(updatedNode.Status.Conditions)-1].Type != api.NodeReady {
-		t.Errorf("unexpected node condition order. NodeReady should be last.")
-	}
+	// Should report kubelet not ready if the runtime check is out of date
+	clock.SetTime(time.Now().Add(-maxWaitForContainerRuntime))
+	kubelet.updateRuntimeUp()
+	checkNodeStatus(api.ConditionFalse, "KubeletNotReady", downMessage)
 
-	if !api.Semantic.DeepEqual(expectedNode, updatedNode) {
-		t.Errorf("unexpected objects: %s", util.ObjectDiff(expectedNode, updatedNode))
-	}
+	// Should report kubelet not ready if the runtime check failed
+	fakeRuntime := testKubelet.fakeRuntime
+	// Inject error into fake runtime status check, node should be NotReady
+	fakeRuntime.StatusErr = fmt.Errorf("injected runtime status error")
+	clock.SetTime(time.Now())
+	kubelet.updateRuntimeUp()
+	checkNodeStatus(api.ConditionFalse, "KubeletNotReady", downMessage)
 }
 
 func TestUpdateNodeStatusError(t *testing.T) {

pkg/kubelet/rkt/rkt.go

@@ -184,13 +184,6 @@ func New(config *Config,
 		rkt.imagePuller = kubecontainer.NewImagePuller(recorder, rkt, imageBackOff)
 	}
 
-	if err := rkt.checkVersion(minimumRktBinVersion, recommendedRktBinVersion, minimumAppcVersion, minimumRktApiVersion, minimumSystemdVersion); err != nil {
-		// TODO(yifan): Latest go-systemd version have the ability to close the
-		// dbus connection. However the 'docker/libcontainer' package is using
-		// the older go-systemd version, so we can't update the go-systemd version.
-		rkt.apisvcConn.Close()
-		return nil, err
-	}
 	return rkt, nil
 }
 
@@ -1062,7 +1055,12 @@ func (r *Runtime) Version() (kubecontainer.Version, error) {
 }
 
 func (r *Runtime) APIVersion() (kubecontainer.Version, error) {
-	return r.binVersion, nil
+	return r.apiVersion, nil
+}
+
+// Status returns error if rkt is unhealthy, nil otherwise.
+func (r *Runtime) Status() error {
+	return r.checkVersion(minimumRktBinVersion, recommendedRktBinVersion, minimumAppcVersion, minimumRktApiVersion, minimumSystemdVersion)
 }
 
 // SyncPod syncs the running pod to match the specified desired pod.

pkg/kubelet/runtime.go

@@ -30,7 +30,6 @@ type runtimeState struct {
 	internalError            error
 	cidr                     string
 	initError                error
-	runtimeCompatibility     func() error
 }
 
 func (s *runtimeState) setRuntimeSync(t time.Time) {
@@ -85,16 +84,12 @@ func (s *runtimeState) errors() []string {
 	if s.internalError != nil {
 		ret = append(ret, s.internalError.Error())
 	}
-	if err := s.runtimeCompatibility(); err != nil {
-		ret = append(ret, err.Error())
-	}
 	return ret
 }
 
 func newRuntimeState(
 	runtimeSyncThreshold time.Duration,
 	configureNetwork bool,
-	runtimeCompatibility func() error,
 ) *runtimeState {
 	var networkError error = nil
 	if configureNetwork {
@@ -105,6 +100,5 @@ func newRuntimeState(
 		baseRuntimeSyncThreshold: runtimeSyncThreshold,
 		networkError:             networkError,
 		internalError:            nil,
-		runtimeCompatibility:     runtimeCompatibility,
 	}
 }