Setup k3s

This ansible role downloads, installs and starts k3s, a lightweight Kubernetes distribution.

What's special about this role

There are a few other k3s Ansible roles available on Ansible Galaxy. These points make this script special:

• when downloading k3s binaries, the old ones remain in the subdirectory within k3s_install_path. Only the links from /usr/local/bin/ are updated. This means, that if you want to go to a specific version, you are always free to go back to the other version just by replacing the symlinks 'k3s', 'kubectl' and 'crictl' in /usr/local/bin.

• this role uses the same terminology as k3s does: server, agent, etc.

• fully tested with Molecule

Prerequisites

Variables

You might want to override the following variables (i.e. in group_vars or host_vars):

• k3s_install_path: "/opt/k3s"
• k3s_server_options:
• k3s_agent_options:
• k3s_version:

Server group

Make sure to declare the host, which should act as server, in the following group: [k3s_server].

Example

Hosts file:

[k3s]
192.168.2.90
192.168.2.91
192.168.2.92

[k3s_server]
192.168.2.90

Playbook:

- hosts: k3s
  become: true
  roles:
    - role: k3s

Test

• Run molecule test --all
  • Scenarios exist for Debian (default), Ubuntu and CentOS

Debugging tests

1. Run molecule test --destroy=never to run the default scenario.
2. Then login to the machine with molecule login -h <molecule-k3s-agent|molecule-k3s-master>.
3. Destroy the machines afterwards with molecule destroy.