GitHub Actions Runner

Built on ubuntu:20.04, configured for rootless dind 🎉, impossible without invaluable advice from @kenichi-shibata and @sidick.

Inspiration from

• https://github.com/cruizba/ubuntu-dind showed me it was possible on ubuntu
• https://github.com/myoung34/docker-github-actions-runner showed it running docker outside docker - inspired API and wrote some README - rights theirs
• https://github.com/docker-library/docker/tree/master/20.10/dind-rootless for their outstanding work

Images

• msyea/ubuntu-docker
• msyea/ubuntu-dind
• msyea/github-actions-runner

Docker Github Actions Runner

This will run the new self-hosted github actions runners.

Environment Variables

Environment Variable	Description
RUNNER_NAME	The name of the runner to use. Supercedes (overrides) RUNNER_NAME_PREFIX
RUNNER_NAME_PREFIX	A prefix for a randomly generated name (followed by a random 13 digit string). You must not also provide RUNNER_NAME. Defaults to github-runner
ACCESS_TOKEN	A github PAT to use to generate RUNNER_TOKEN dynamically at container start. Not using this requires a valid RUNNER_TOKEN
ORG_RUNNER	Only valid if using ACCESS_TOKEN. This will set the runner to an org runner. Default is 'false'. Valid values are 'true' or 'false'. If this is set to true you must also set ORG_NAME and makes REPO_URL unneccesary
ORG_NAME	The organization name for the runner to register under. Requires ORG_RUNNER to be 'true'. No default value.
LABELS	A comma separated string to indicate the labels. Default is 'default'
REPO_URL	If using a non-organization runner this is the full repository url to register under such as 'https://github.com/msyea/repo'
RUNNER_TOKEN	If not using a PAT for ACCESS_TOKEN this will be the runner token provided by the Add Runner UI (a manual process). Note: This token is short lived and will change frequently. ACCESS_TOKEN is likely preferred.
RUNNER_WORKDIR	The working directory for the runner. Runners on the same host should not share this directory. Default is '/_work'. This must match the source path for the bind-mounted volume at RUNNER_WORKDIR, in order for container actions to access files.
RUNNER_GROUP	Name of the runner group to add this runner to (defaults to the default runner group)
GITHUB_HOST	Optional URL of the Github Enterprise server e.g github.mycompany.com. Defaults to github.com.

Manual

# org runner
docker run -d --restart always --name github-runner \
  -e RUNNER_NAME_PREFIX="myrunner" \
  -e ACCESS_TOKEN="footoken" \
  -e RUNNER_WORKDIR="/tmp/github-runner-your-repo" \
  -e RUNNER_GROUP="my-group" \
  -e ORG_RUNNER="true" \
  -e ORG_NAME="octokode" \
  -e LABELS="my-label,other-label" \
  msyea/github-actions-runner:latest
# per repo
docker run -d --restart always --name github-runner \
  -e REPO_URL="https://github.com/msyea/repo" \
  -e RUNNER_NAME="foo-runner" \
  -e RUNNER_TOKEN="footoken" \
  -e RUNNER_WORKDIR="/tmp/github-runner-your-repo" \
  -e RUNNER_GROUP="my-group" \
  msyea/github-actions-runner:latest

Or shell wrapper:

function github-runner {
    name=github-runner-${1//\//-}
    org=$(dirname $1)
    repo=$(basename $1)
    tag=${3:-latest}
    docker rm -f $name
    docker run -d --restart=always \
        -e REPO_URL="https://github.com/${org}/${repo}" \
        -e RUNNER_TOKEN="$2" \
        -e RUNNER_NAME="linux-${repo}" \
        -e RUNNER_WORKDIR="/tmp/github-runner-${repo}" \
        -e RUNNER_GROUP="my-group" \
        -e LABELS="my-label,other-label" \
        --name $name ${org}/github-runner:${tag}
}

github-runner your-account/your-repo       AARGHTHISISYOURGHACTIONSTOKEN
github-runner your-account/some-other-repo ARGHANOTHERGITHUBACTIONSTOKEN ubuntu-xenial

Or docker-compose.yml:

version: '2.3'

services:
  worker:
    image: msyea/github-actions-runner:latest
    environment:
      REPO_URL: https://github.com/example/repo
      RUNNER_NAME: example-name
      RUNNER_TOKEN: someGithubTokenHere
      RUNNER_GROUP: my-group
      ORG_RUNNER: 'false'
      LABELS: linux,x64,gpu

Usage From GH Actions Workflow

name: Package

on:
  release:
    types: [created]

jobs:
  build:
    runs-on: self-hosted
    steps:
    - uses: actions/checkout@v1
    - name: build packages
      run: make all

Automatically Acquiring a Runner Token

A runner token can be automatically acquired at runtime if ACCESS_TOKEN (a GitHub personal access token) is a supplied. This uses the GitHub Actions API. e.g.:

docker run -d --restart always --name github-runner \
  -e ACCESS_TOKEN="footoken" \
  -e RUNNER_NAME="foo-runner" \
  -e RUNNER_WORKDIR="/tmp/github-runner-your-repo" \
  -e RUNNER_GROUP="my-group" \
  -e ORG_RUNNER="true" \
  -e ORG_NAME="octokode" \
  -e LABELS="my-label,other-label" \
  msyea/github-actions-runner:latest

Create GitHub personal access token

Creating GitHub personal access token (PAT) for using by self-hosted runner make sure the following scopes are selected:

• repo (all)
• admin:org (all) (mandatory for organization-wide runner)
• admin:public_key - read:public_key
• admin:repo_hook - read:repo_hook
• admin:org_hook
• notifications
• workflow

Also, when creating a PAT for self-hosted runner which will process events from several repositories of the particular organization, create the PAT using organization owner account. Otherwise your new PAT will not have sufficient privileges for all repositories.