Yesterday I got many issue accessing my Cluster, it was not the DNS this time, I didn't know what is the issue, the error message was not clear

You must be logged in to the server (Unauthorized)

Trying to access the cluster via kubctl throw an error, as if the first one was not clear the second one was even more mysterious for me

couldn't get current server API group list: the server has asked for the client to provide credentials

I tried to redownload the credential file, I thought that the one I have locally was damaged or something, but with no luck.

While searching for a solution, I stumbled with an article about  the same issue, so I tried to check and YAY, the certificate is indeed has been expired.

So, after some more digging into K3s documentation, I found the solution in 3 steps:

1. Stop the Cluster Server

systemctl stop k3s

2. Rotate your certificate

k3s certificate rotate

3. Start the Cluster Server

systemctl start k3s

You can read more about it here, and this is my tip for today.