Kubernetes Sidecar Pattern Lab Issue - initContainer with infinite loop keeps Pod in Init state

Kubernetes
#1

Hi KodeKloud Team,

I am facing an issue with the “Sidecar Pattern” Kubernetes task.

The task asks to:

  • Create a pod named webserver

  • Create an emptyDir volume named shared-logs

  • Create:

    • a regular container nginx-container using nginx:latest
    • an init container sidecar-container using ubuntu:latest

  • Add this command to the sidecar container:

"sh","-c","while true; do cat /var/log/nginx/access.log /var/log/nginx/error.log; sleep 30; done"

The problem is:

  • sidecar-container is defined as an initContainer
  • but the command contains while true
  • init containers never complete because of the infinite loop
  • therefore the main nginx container never starts
  • pod remains stuck in:
Init:0/1

If I move sidecar-container to regular containers, the pod works correctly (2/2 Running), but the validator fails saying the init container does not exist.

Could you please clarify whether:

  1. sidecar-container should actually be a regular container instead of an init container?
  2. or if the validator/task definition needs correction?

Thanks.

#2

The problem you’re having here: if you use an initContainer as a sidecar, you must set “restartPolicy: Always” for that initContainer, or you’ll get the problem you’re having. So that is the likely fix. See this doc page for more info.

#3

Thank you for the clarification.

You were absolutely right - adding: restartPolicy: Always to the sidecar-container initContainer fixed the issue.

After applying that configuration, both containers came up successfully and the pod reached 2/2 Running.

I also learned about restartable sidecar init containers from the Kubernetes documentation you shared. Thanks for pointing me in the right direction.