Build a Kubernetes cluster using k3s via Ansible

Author: https://github.com/itwars

K3s Ansible Playbook

Build a Kubernetes cluster using Ansible with k3s. The goal is easily install a Kubernetes cluster on machines running:

• Debian
• Ubuntu
• CentOS

on processor architecture:

• x64
• arm64
• armhf

System requirements

Deployment environment must have Ansible 2.4.0+ Master and nodes must have passwordless SSH access

Variables

Variable	Example	Description
ansible_user	ubuntu	user to connect via ssh to to master
ansible_ssh_private_key_file	./secrets/id_rsa	ssh private key file
k3s_version	1.25.9+k3s1	k3s version from https://github.com/k3s-io/k3s/releases
systemd_dir	/etc/systemd/system	path to systemd
master_address	192.168.1.2	master node address or FQDN (used only for single node)

Single node cluster

Edit inventory/single_node/group_vars/all.yml to match your environment.

ansible-playbook site.yml -i inventory/single_node/hosts.ini --extra-vars "master_address=192.168.1.2"

Multiple nodes cluster

First create a new directory based on the sample directory within the inventory directory:

cp -R inventory/sample inventory/my-cluster

Second, edit inventory/my-cluster/hosts.ini to match the system information gathered above. For example:

[master]
192.16.35.12

[node]
192.16.35.[10:11]

[k3s_cluster:children]
master
node

If needed, you can also edit inventory/my-cluster/group_vars/all.yml to match your environment.

Start provisioning of the cluster using the following command:

ansible-playbook site.yml -i inventory/my-cluster/hosts.ini

Reset node

Run the following playbook against the original inventory used to deploy the nodes, ex.

ansible-playbook reset.yml -i inventory/my-cluster/hosts.ini

or

ansible-playbook reset.yml -i inventory/single_node/hosts.ini --extra-vars "master_address=192.168.1.2"

Kubeconfig

To get access to your Kubernetes cluster just

scp ubuntu@master_ip:~/.kube/config ~/.kube/config