Yesterday, my kubernetes cluster is suddenly down I tried to investigate as the follows but not sure what the reason was:
Unable to access Kube Dashboard, it returns HTTP ERROR 502
Unable to access deployed apps on cluster, it also returns 502 error
Cannot use kubectl command, it shows the message: "Unable to connect to the server: x509: certificate has expired or is not yet valid"
With this error, I googled and got the article. But I'm not sure if this is correct or not.
Can you please help to advise.
Thank you so much.
Environment: