Multi-node MicroK8s

Adding a node

To create a cluster out of two or more already-running MicroK8s instances, use the microk8s.add-node command. The MicroK8s instance on which this command is run will be the master of the cluster and will host the Kubernetes control plane:

> microk8s.add-node
Join node with: microk8s.join ip-172-31-20-243:25000/DDOkUupkmaBezNnMheTBqFYHLWINGDbf

If the node you are adding is not reachable through the default
interface you can use one of the following:
 microk8s.join 10.1.84.0:25000/DDOkUupkmaBezNnMheTBqFYHLWINGDbf
 microk8s.join 10.22.254.77:25000/DDOkUupkmaBezNnMheTBqFYHLWINGDbf

The add-node command prints a microk8s.join command which should be executed on the MicroK8s instance that you wish to join to the cluster:

> microk8s.join ip-172-31-20-243:25000/DDOkUupkmaBezNnMheTBqFYHLWINGDbf

Joining a node to the cluster should only take a few seconds. Afterwards you should be able to see the node has joined:

> microk8s.kubectl get no
NAME               STATUS   ROLES    AGE   VERSION
10.22.254.79       Ready    <none>   27s   v1.15.3
ip-172-31-20-243   Ready    <none>   53s   v1.15.3

Removing a node

To remove a node from the cluster, use microk8s.remove-node:

> microk8s.remove-node 10.22.254.79

Finally, on the removed node, run microk8s.leave. MicroK8s will restart its own control plane and resume operations as a full single node cluster:

> microk8s.leave