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.