RKE2 re-register existing nodes

[wrender]

Is your feature request related to a problem? Please describe.
In RKE1 we could re-provision ephemeral hosts and have them re-register into the cluster over top of the existing node name. Without changing the dns/nodeName to something new. This was great in our environment as we often re-use the dns name on the hosts as they are bare metal.

Describe the solution you'd like
Would it be possible to have an option with RKE2 to allow nodes re-registering in with the same dns/nodeName and basically overwrite the existing node that was registered in the cluster?

[brandond]

If you want to re-register with the same name, you need to either retain the node password file, or delete the node password secret. This is covered in the docs at https://docs.rke2.io/advanced

Agents register with the server using the cluster secret portion of the join token, along with a randomly generated node-specific password, which is stored on the agent at /etc/rancher/node/password. The server will store the passwords for individual nodes as Kubernetes secrets, and any subsequent attempts must use the same password. Node password secrets are stored in the kube-system namespace with names using the template .node-password.rke2. These secrets are deleted when the corresponding Kubernetes node is deleted.

If the /etc/rancher/node directory of an agent is removed, the password file should be recreated for the agent prior to startup, or the entry removed from the server or Kubernetes cluster (depending on the RKE2 version).