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vitobotta / hetzner-k3s

The easiest and fastest way to create and manage Kubernetes clusters in Hetzner Cloud using the lightweight distribution k3s by Rancher.
MIT License
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When replacing a worker node it doesn't join cluster (duplicate hostname) #390

Closed filidorwiese closed 1 month ago

filidorwiese commented 1 month ago

Hi! I'm running a k3s cluster (version v1.29.3+k3s1) using hetzner-k3s and had to replace a failing node. As found in the README of this project I did that with the kubectl delete node command. Followed by deleting the worker vm in Hetzner console and then running hetzner-k3s create --config ./hetzner-k3s.yml. However the process hangs when trying to start the k3s-agent on the node and never becomes available as a new worker node in k3s. I manually have to kill the hetzner-k3s script.

The systemctl status k3s-agent logs on the partially installed worker node gives a clue:

Waiting to retrieve agent configuration; server is not ready: Node password rejected, duplicate hostname or contents of '/etc/rancher/node/password' may not match server node-passwd entry, try enabling a unique node name with the --with-node-id flag

Probably the master nodes (I'm running in HA) still have the old worker password, while a new one has been generated on the worker node itself (which has the exact same hostname since I'm replacing the node). I probably need to clear the old config form the master nodes, but I'm not sure how achieve that and don't want to mess up my cluster.

Any help would be appreciated.

filidorwiese commented 1 month ago

Okay, I found the solution, which I'll post here for posterity.

After running kubectl delete node (and before you run hetzner-k3s create) make sure to also manually delete the worker node password that is stored as a kubernetes secret in the kube-system namespace with a name like your-node-k3s-ccx33-pool-v2-worker2.node-password.k3s. It will be re-created when running hetzner-k3s create.

This might be a good addition to the README. Keep up the good work!