View crashed Pod logs (previous logs)

[illume]

When I am troubleshooting a Pod that has crashed or restarted, I want to be able to view the logs from its previous container instance, so I can understand what caused the failure and take corrective action.

With kubectl you can see the logs for a crashed Pod like this:

kubectl logs <pod-name> --previous
kubectl logs <pod-name> -c <container-name> --previous

API:

GET /api/v1/namespaces/{namespace}/pods/{pod}/log?previous=true

previous=true: fetches logs from the previous container instance, which is useful when the container has crashed or restarted.

We need to design and agree a UI before implementation:

• Maybe an option on the log viewer page?
• Or a separate action "View previous logs" button?

Additional context

See:

• kubectl logs command reference: https://kubernetes.io/docs/reference/kubectl/generated/kubectl_logs/
• Debugging running or crashing pods: https://kubernetes.io/docs/tasks/debug/debug-application/debug-running-pod/
• Logging architecture overview (includes --previous usage): https://kubernetes.io/docs/concepts/cluster-administration/logging/
• For example yaml to make a Pod terminate "termination-demo" https://kubernetes.io/docs/tasks/debug/debug-application/determine-reason-pod-failure/

This was one of the most requested features in dashboard: kubernetes/dashboard#1393 https://github.com/kubernetes/dashboard/pull/2392/files and is a commonly used feature of kubectl.

[karankoder]

Hello @illume
Can i work on this issue?

[illume]

@karankoder sure!

Please type /assign in a comment to assign yourself if you want to do it.

[eyeaadil]

/assign