slimtoolkit/slim · error

Container terminated

Error message

Container terminated

What it means

ErrContainerTerminated is returned from HandleKubernetesRuntime (and the debug runtime flow) when the specific container targeted for debugging has terminated. Even if the pod is running, an exited container cannot be attached to or instrumented.

Source

Thrown at pkg/app/master/command/debug/handle_kubernetes_runtime.go:1001

	err := wait.PollImmediate(2*time.Second, 2*time.Minute, isPodRunning)
	if err != nil {
		return nil, "", err
	}

	return outputPod, podName, nil
}

const (
	ctInit      = "init"
	ctStandard  = "standard"
	ctEphemeral = "ephemeral"
)

var (
	ErrPodTerminated       = errors.New("Pod terminated")
	ErrPodNotRunning       = errors.New("Pod not running")
	ErrContainerTerminated = errors.New("Container terminated")
)

func waitForContainer(
	logger *log.Entry,
	xc *app.ExecutionContext,
	ctx context.Context,
	api *kubernetes.Clientset,
	nsName string,
	podName string,
	containerName string,
	containerType string) error {
	logger.Tracef("waitForContainer(%s,%s,%s,%s)", nsName, podName, containerName, containerType)

	isContainerRunning := func() (bool, error) {
		pod, err := api.CoreV1().Pods(nsName).Get(ctx, podName, metav1.GetOptions{})
		if err != nil {
			return false, err
		}

View on GitHub (pinned to 81940d17fa)

Solutions

1. Check container state with kubectl describe pod and pick a currently running container name
2. Prevent the app from exiting during debugging or use an ephemeral debug container strategy
3. Re-run the debug command immediately after restarting the container

Example fix

kubectl debug -it my-pod --image=busybox --target=my-app  # debug via ephemeral container instead of attaching to the exited one

cs, _ := clientset.CoreV1().Pods(ns).Get(ctx, pod, metav1.GetOptions{})
for _, st := range cs.Status.ContainerStatuses {
	if st.Name == target && st.State.Running == nil {
		return fmt.Errorf("container %s is not running", target)
	}
}

// Go
if errors.Is(err, ErrContainerTerminated) {
	// re-run with a running container or use kubectl debug ephemeral container
}

When it happens

Trigger: Selecting a container that exited before the debug attach; the target process crashes during waitForContainer; naming a sidecar/ephemeral container that already finished.

Common situations: Debugging an app container that crashed; wrong container name passed (e.g. an init container); short-lived containers that finish before the debugger connects.

Related errors

• Pod terminated
• Pod not running
• malformed Kubernetes workload name
• not a terminal
• start monitor timeout

AI-assisted analysis of slimtoolkit/slim@81940d17fa (2026-08-31). Data as JSON: /api/errors/943430dd2791e80a. Report an issue: GitHub.