nodes.md

Adding/replacing a node

Modified from comments in #3471

Limitation: Removal of first kube_control_plane and etcd-master

Currently you can't remove the first node in your kube_control_plane and etcd-master list. If you still want to remove this node you have to:

1) Change order of current masters

Modify the order of your master list by pushing your first entry to any other position. E.g. if you want to remove node-1 of the following example:

  children:
    kube_control_plane:
      hosts:
        node-1:
        node-2:
        node-3:
    kube_node:
      hosts:
        node-1:
        node-2:
        node-3:
    etcd:
      hosts:
        node-1:
        node-2:
        node-3:

change your inventory to:

  children:
    kube_control_plane:
      hosts:
        node-2:
        node-3:
        node-1:
    kube_node:
      hosts:
        node-2:
        node-3:
        node-1:
    etcd:
      hosts:
        node-2:
        node-3:
        node-1:

2) Upgrade the cluster

run upgrade-cluster.yml or cluster.yml. Now you are good to go on with the removal.

Adding/replacing a worker node

This should be the easiest.

1) Add new node to the inventory

2) Run scale.yml

You can use --limit=NODE_NAME to limit Kubespray to avoid disturbing other nodes in the cluster.

Before using --limit run playbook facts.yml without the limit to refresh facts cache for all nodes.

3) Remove an old node with remove-node.yml

With the old node still in the inventory, run remove-node.yml. You need to pass -e node=NODE_NAME to the playbook to limit the execution to the node being removed.

If the node you want to remove is not online, you should add reset_nodes=false to your extra-vars: -e node=NODE_NAME -e reset_nodes=false. Use this flag even when you remove other types of nodes like a master or etcd nodes.