How To Resolve The Kubernetes CrashLoopBackOff Pod State

Background

CrashLoopBackOff is a Kubernetes state that indicates that a pod is in a restart loop; a container in the pod is started but crashes or is terminated, the container is restarted, but it crashes or is terminated over and over again. The CrashLoopBackOff is not, in itself, an error but rather it indicates that there is an error that is preventing a pod from starting properly. Kubernetes will wait for longer and longer periods between each restart (the back-off time) to give you an opportunity to address the underlying error. A CrashLoopBackOff state can be caused by issues that include:

• Misconfigurations in the application
• Application resources are not available
• Application bugs and exceptions
• Attempting to bind to an existing port
• Memory limits that are too low
• Liveness probe errors that prevent reporting the pod as ready
• Incorrect permissions to access required resources

Solution

• Check the pod description: Check for misconfigurations in:
• • The pod definition
  • The container
  • The image pulled for the container
  • The resources allocated for the container
  • Any wrong or missing arguments
• Check the logs: Look at the logs of the failing container to see if there are any helpful error messages, stack traces, or events listed.
• Debug the container: If the logs don't provide enough information, try to debug the container by running it locally or by attaching to a running instance of the container using kubectl exec or kubectl attach.
• If there is a deployment that defines the desired pod state, verify that there are no misconfigurations that are causing the CrashLoopBackOff.