Restart the init container to not be stuck in created state

The main sync loop should have created and started the container in one
step. If the init container is in the 'created' state, it's likely that
the container runtime failed to start it. To prevent the container from
getting stuck in the 'created' state, restart it.

Author: gjkim42

pkg/kubelet/kuberuntime/kuberuntime_container.go

@@ -1084,7 +1084,12 @@ func (m *kubeGenericRuntimeManager) computeInitContainerActions(pod *v1.Pod, pod
 
 		switch status.State {
 		case kubecontainer.ContainerStateCreated:
-			// nothing to do but wait for it to start
+			// The main sync loop should have created and started the container
+			// in one step. If the init container is in the 'created' state,
+			// it is likely that the container runtime failed to start it. To
+			// prevent the container from getting stuck in the 'created' state,
+			// restart it.
+			changes.InitContainersToStart = append(changes.InitContainersToStart, i)
 
 		case kubecontainer.ContainerStateRunning:
 			if !types.IsRestartableInitContainer(container) {

pkg/kubelet/kuberuntime/kuberuntime_manager_test.go

@@ -1170,6 +1170,17 @@ func TestComputePodActions(t *testing.T) {
 				ContainersToStart: []int{1},
 			},
 		},
+		"Restart the container if the container is in created state": {
+			mutatePodFn: func(pod *v1.Pod) { pod.Spec.RestartPolicy = v1.RestartPolicyNever },
+			mutateStatusFn: func(status *kubecontainer.PodStatus) {
+				status.ContainerStatuses[1].State = kubecontainer.ContainerStateCreated
+			},
+			actions: podActions{
+				SandboxID:         baseStatus.SandboxStatuses[0].Id,
+				ContainersToKill:  map[kubecontainer.ContainerID]containerToKillInfo{},
+				ContainersToStart: []int{1},
+			},
+		},
 	} {
 		pod, status := makeBasePodAndStatus()
 		if test.mutatePodFn != nil {
@@ -1527,12 +1538,17 @@ func TestComputePodActionsWithRestartableInitContainers(t *testing.T) {
 				ContainersToKill:      getKillMapWithInitContainers(basePod, baseStatus, []int{}),
 			},
 		},
-		"initialization in progress; do nothing": {
+		"an init container is stuck in the created state; restart it": {
 			mutatePodFn: func(pod *v1.Pod) { pod.Spec.RestartPolicy = v1.RestartPolicyAlways },
 			mutateStatusFn: func(pod *v1.Pod, status *kubecontainer.PodStatus) {
 				status.ContainerStatuses[2].State = kubecontainer.ContainerStateCreated
 			},
-			actions: noAction,
+			actions: podActions{
+				SandboxID:             baseStatus.SandboxStatuses[0].Id,
+				InitContainersToStart: []int{2},
+				ContainersToStart:     []int{},
+				ContainersToKill:      getKillMapWithInitContainers(basePod, baseStatus, []int{}),
+			},
 		},
 		"restartable init container has started; start the next": {
 			mutatePodFn: func(pod *v1.Pod) { pod.Spec.RestartPolicy = v1.RestartPolicyAlways },