Always restart container in unknown state.

pkg/kubelet/container/helpers.go

@@ -57,6 +57,10 @@ func ShouldContainerBeRestarted(container *api.Container, pod *api.Pod, podStatu
 	if status.State == ContainerStateRunning {
 		return false
 	}
+	// Always restart container in unknown state now
+	if status.State == ContainerStateUnknown {
+		return true
+	}
 	// Check RestartPolicy for dead container
 	if pod.Spec.RestartPolicy == api.RestartPolicyNever {
 		glog.V(4).Infof("Already ran container %q of pod %q, do nothing", container.Name, format.Pod(pod))

pkg/kubelet/container/helpers_test.go

@@ -148,6 +148,7 @@ func TestShouldContainerBeRestarted(t *testing.T) {
 				{Name: "alive"},
 				{Name: "succeed"},
 				{Name: "failed"},
+				{Name: "unknown"},
 			},
 		},
 	}
@@ -175,6 +176,10 @@ func TestShouldContainerBeRestarted(t *testing.T) {
 				State:    ContainerStateExited,
 				ExitCode: 2,
 			},
+			{
+				Name:  "unknown",
+				State: ContainerStateUnknown,
+			},
 			{
 				Name:     "failed",
 				State:    ContainerStateExited,
@@ -192,6 +197,7 @@ func TestShouldContainerBeRestarted(t *testing.T) {
 		"alive":      {false, false, false},
 		"succeed":    {false, false, true},
 		"failed":     {false, true, true},
+		"unknown":    {true, true, true},
 	}
 	for _, c := range pod.Spec.Containers {
 		for i, policy := range policies {

pkg/kubelet/dockertools/manager.go

@@ -345,6 +345,7 @@ func (dm *DockerManager) inspectContainer(id string, podName, podNamespace strin
 		Hash:         hash,
 	}
 	if iResult.State.Running {
+		// Container that are running, restarting and paused
 		status.State = kubecontainer.ContainerStateRunning
 		status.StartedAt = iResult.State.StartedAt
 		if containerName == PodInfraContainerName {
@@ -355,6 +356,7 @@ func (dm *DockerManager) inspectContainer(id string, podName, podNamespace strin
 
 	// Find containers that have exited or failed to start.
 	if !iResult.State.FinishedAt.IsZero() || iResult.State.ExitCode != 0 {
+		// Containers that are exited, dead or created (docker failed to start container)
 		// When a container fails to start State.ExitCode is non-zero, FinishedAt and StartedAt are both zero
 		reason := ""
 		message := iResult.State.Error
@@ -394,8 +396,8 @@ func (dm *DockerManager) inspectContainer(id string, podName, podNamespace strin
 		status.StartedAt = startedAt
 		status.FinishedAt = finishedAt
 	} else {
-		// Non-running containers that are not terminatd could be pasued, or created (but not yet
-		// started), etc. Kubelet doesn't handle these scenarios yet.
+		// Non-running containers that are created (not yet started or kubelet failed before calling
+		// start container function etc.) Kubelet doesn't handle these scenarios yet.
 		status.State = kubecontainer.ContainerStateUnknown
 	}
 	return &status, "", nil