Failed to verify certificate: x509

[clickersmudge]

Hello Kubermatic team.
We have a big problem with one of the oldest clusters. Certificates stopped renewing on it, which resulted in some pods not working

When logging into kubectl we get an error

Unable to connect to the server: tls: failed to verify certificate: x509: certificate has expired or is not yet valid: current time 2025-03-28T15:30:37+01:00 is after 2024-09-26T19:52:49Z

Can we ask for help? We don't know where to start. How to renew these certificates?

[kron4eg]

Hello!

Please take a look at the docs page: https://docs.kubermatic.com/kubeone/v1.9/guides/certificate-management/

[clickersmudge]

Hi @kron4eg ,

The problem is that, our version is KubeOne 1.7 and a working cluster.

After firing up:

kubeone apply -credentials credentials.yaml --manifest kubeone.yaml --tfjson tf.json --force-upgrade

Please help to fix this. Probably the update won't run either.

[kron4eg]

OK, then seems like you will need to go over each node over ssh and run

kubeadm certs renew all

see more https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-certs/#manual-certificate-renewal

[clickersmudge]

@kron4eg Thanks, you saved us a cluster.