This is an unsupported scenario, see rancher/rancher#14731 when there is an official solution.
When cattle-cluster-agent and/or cattle-node-agent are accidentally deleted, or when server-url/cacerts are changed.
- Generate API token in the UI (user -> API & Keys) and save the Bearer token
- Find the clusterid in the Rancher UI (format is
c-xxxxx), its in the address bar when the cluster is selected