Introduction

Forked from https://github.com/stgraber/lxd-github-actions

This repository contains some scripts to create LXD instances suitable to be used as Github Actions runners as well as tools to spawn a set of such instances.

This will use LXD with a set of ephemeral instances which will then be added as Github Runners. Each of those will process exactly one job and then self-destroy. This is to avoid running jobs in unclean environments, preventing one job from impacting or attacking the next.

Installing LXD

sudo apt-get install lxd-client

lxd init
#you can use all the defaults

#Add new storge pool called docker (docker needs btrfs to work properly, so we named its storage pool docker)
lxc storage create docker btrfs source=/var/lxd/disks size=30GB

Creating a suitable base instance

For example, for an Ubuntu 20.04 container, you'd use:

lxc launch images:ubuntu/20.04 gh-runner

Do Once :

Setup a PAT (Personal access token) with access to the repos and orgs you want serviced. https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token

• Enable the following scopes:
  • repo
  • workflow
  • admin:org
  • admin:repo_hook

Prepare the LXD container with all its depedencies (You might need to modify this to fit your needs)

./prepare-instance gh-runner

Starting some runners

Spawn LXD github-runners :

./respawn gh-runner RUNNER_COUNT https://github.com/ORG/REPO PAT label1,label2

• gh-runner (or the name of your base container)
• RUNNER_COUNT : (number of gh-runners that will run in parallel)
• repository address
• PAT (starting with ghg_...)
• LABELS (optinal)

Create a cronjob that executes job above once per minute to respawn any number of missing runners :

crontab -e
>>>
* * * * * /path/to/lxd-runner/respawn gh-runner RUNNER_COUNT https://github.com/ORG/REPO PAT