Ham

Posted on Oct 31

Edited on Oct 31

By default, when you setup your Kubernetes cluster, the certificates expires after one year.

The process to check is exactly like the process explained in https://dev.to/hatr0/fixing-expired-certificates-in-kubernetes-1oe2 .

I have copied and paste all the needed commands here so no need to visit the post.

Try to issue kubectl commands and you will notice connection refused errors.

The below commands requires 'root' privileged, so if you are login as non-root, you will need to prepend sudo before the commands.

Troubleshooting further, you noticed that your kubelet service is failing to start ( systemctl status kubelet ).

Upon checking logs related with kubelet ( journalctl | grep kubelet ), you noticed the belong error messages.

Since the kubelet service on worker nodes talks to control plane, an expired license will prevent the kubelet from authenticating with the API server.

Let's verify our issue with the 'openssl' command.

Let's check kubelet client…