2.3 KiB
Shrinking a cluster
This document describes the method for shrinking a cluster, by removing a worker nodes.
Assumptions
It is assumed that you have already deployed a k3s cluster using this role, you have an appropriately configured inventory and playbook to create the cluster.
Below, our example inventory and playbook are as follows:
- inventory:
inventory.yml - playbook:
cluster.yml
Currently your inventory.yml looks like this, it has three nodes defined,
kube-0 (control node) and kube-1, kube-2 (worker nodes).
---
k3s_cluster:
hosts:
kube-0:
ansible_user: ansible
ansible_host: 10.10.9.2
ansible_python_interpreter: /usr/bin/python3
kube-1:
ansible_user: ansible
ansible_host: 10.10.9.3
ansible_python_interpreter: /usr/bin/python3
kube-2:
ansible_user: ansible
ansible_host: 10.10.9.4
ansible_python_interpreter: /usr/bin/python3
Method
We have our three nodes, one control, two workers. The goal is to shrink this to
remove excess capacity by offboarding the worker node kube-2. To do this we
will set kube-2 node to k3s_state: uninstalled in our inventory.
---
k3s_cluster:
hosts:
kube-0:
ansible_user: ansible
ansible_host: 10.10.9.2
ansible_python_interpreter: /usr/bin/python3
kube-1:
ansible_user: ansible
ansible_host: 10.10.9.3
ansible_python_interpreter: /usr/bin/python3
kube-2:
ansible_user: ansible
ansible_host: 10.10.9.4
ansible_python_interpreter: /usr/bin/python3
k3s_state: uninstalled
What you will typically see is changes to your control plane (kube-0) and the
node being removed (kube-2). The role will register the removal of the node
with the cluster by draining the node and removing it from the cluster.
PLAY RECAP *******************************************************************************************************
kube-0 : ok=55 changed=2 unreachable=0 failed=0 skipped=28 rescued=0 ignored=0
kube-1 : ok=40 changed=0 unreachable=0 failed=0 skipped=35 rescued=0 ignored=0
kube-2 : ok=23 changed=2 unreachable=0 failed=0 skipped=17 rescued=0 ignored=1