How do I fix the CrashLoopBackOff error in my Kubernetes deployment?

All answers to this question.

The CrashLoopBackOff status usually indicates that the container is starting, crashing, and then Kubernetes is trying to restart it with an increasing delay. To diagnose this, start by running kubectl logs [pod-name] to see if the application is throwing an exception during initialization. If the logs are empty, use kubectl describe pod [pod-name] to check the "Events" section. Often, this is caused by incorrect environment variables, missing Secrets, or a liveness probe that is failing because the app takes too long to start. Check your resource limits as well.

   Answered 2024-10-14 by Linda Thompson

Have you verified if the container has enough memory allocated? Sometimes the OOMKiller terminates the process before it can even write to the logs, which makes it look like a configuration loop when it's actually a resource constraint issue.

   Answered 2024-10-15 by Mark Peterson

• Mark, you hit the nail on the head. I checked the describe output and saw the "Reason: OOMKilled" flag. It turns out the new Java runtime version required a bit more overhead than our previous baseline. I adjusted the memory limits in the deployment manifest from 256Mi to 512Mi, and the pods stabilized immediately. Thanks for pointing me toward resource constraints!

     Commented 2024-10-16 by Sarah Jenkins

Check your entrypoint command in the Dockerfile. If the script finishes execution, the container exits, causing K8s to restart it. Ensure your main process stays in the foreground.

   Answered 2024-10-17 by James Miller

• James is right; I’ve seen this happen often with shell scripts that don't use 'exec'. Adding a long-running process or fixing the script entrypoint usually resolves the loop.

     Commented 2024-10-18 by Linda Thompson