Having build a K8s 1.21 cluster a week or so back, I'd removed my Compute Node with: -
kubeadm reset
( run on the Compute Node itself )
I then wanted to find the command that I'd previously used to join the Compute Node to the cluster.
Now kubeadm init generates a token etc. which lives for 24 hours.
So finding the command from hist or from documentation ain't gonna cut it.
Thankfully, we have this: -
kubeadm token create --print-join-command
which generates output such as this: -
kubeadm join 10.51.16.135:6443 --token isahtxb.nfv74gu4yxbxxq2j --discovery-token-ca-cert-hash sha256:1375f426f376b99240ed34bf952f4c026cc0afaad4adbba816187ff5bcc384b6
with which I can then join the Compute Node into the cluster, and we're back up and running ...
Thanks as ever to StackOverflow, who've got my back with: -