Jan 30, 2021

Microk8s: rejoining a node after a reinstall of microk8s


If you are running a microk8s kubernetes cluster, you can hit the scenario, that you lost one node and you have to reinstall the complete os or just the microk8s.

In this case you want to join this node once again to your cluster. But removing the node does not work, because the rest of the cluster can not reach the node (because it is gone...):

root@zigbee:/home/ubuntu# microk8s.remove-node ubuntu
Removal failed. Node ubuntu is registered with dqlite. Please, run first 'microk8s leave' on the departing node.
If the node is not available anymore and will never attempt to join the cluster in the future use the '--force' flag
to unregister the node while removing it.

The solution is given in the failed answer: just add "--force"

root@zigbee:/home/ubuntu# microk8s.remove-node ubuntu --force
root@zigbee:/home/ubuntu# microk8s.add-node
From the node you wish to join to this cluster, run the following:
microk8s join
If the node you are adding is not reachable through the default interface you can use one of the following:
 microk8s join
 microk8s join
 microk8s join

And then the join works without any problem:

root@ubuntu:/home/ubuntu# microk8s join
Contacting cluster at
Waiting for this node to finish joining the cluster. ..  

1 comment:

  1. Thank you! Ran into this exact scenario after somehow blasting snap and screwing everything up.