TIL: How do I find the requisite information to join a Compute Node to an existing K8s Cluster ?

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: -

How do I find the join command for kubeadm on the master?