GitHub Runner

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GitHub allows developers to run GitHub Actions workflows on your own runners. This Docker image allows you to create your own runners on Docker.

For now, there is only a Debian Buster image, but I may add more variants in the future. Feel free to create an issue if you want another base image.

Important notes

GitHub recommends that you do NOT use self-hosted runners with public repositories, for security reasons.

Usage

Basic usage

Use the following command to start listening for jobs:

docker run -it --name my-runner \
    -e RUNNER_NAME=my-runner \
    -e GITHUB_ACCESS_TOKEN=token \
    -e RUNNER_REPOSITORY_URL=https://github.com/... \
    sdigit/github-runner

Using Docker inside your Actions

If you want to use Docker inside your runner (ie, build images in a workflow), you can enable Docker siblings by binding the host Docker daemon socket. Please keep in mind that doing this gives your actions full control on the Docker daemon.

docker run -it --name my-runner \
    -e RUNNER_NAME=my-runner \
    -e GITHUB_ACCESS_TOKEN=token \
    -e RUNNER_REPOSITORY_URL=https://github.com/... \
    -v /var/run/docker.sock:/var/run/docker.sock \
    sdigit/github-runner

Using docker-compose.yml

In docker-compose.yml :

version: "3.7"

services:
    runner:
      image: sdigit/github-runner:latest
      environment:
        RUNNER_NAME: "my-runner"
        RUNNER_REPOSITORY_URL: ${RUNNER_REPOSITORY_URL}
        GITHUB_ACCESS_TOKEN: ${GITHUB_ACCESS_TOKEN}
      volumes:
        - /var/run/docker.sock:/var/run/docker.sock

You can create a .env to provide environment variables when using docker-compose :

RUNNER_REPOSITORY_URL=https://github.com/your_url/your_repo
GITHUB_ACCESS_TOKEN=the_runner_token

Environment variables

The following environment variables allows you to control the configuration parameters.

Name	Description	Default value
RUNNER_REPOSITORY_URL	The runner will be linked to this repository URL	Required
GITHUB_ACCESS_TOKEN	Personal Access Token created on your settings page with repo scole. Used to dynamically fetch a new runner token (recommended).	Required if RUNNER_TOKEN is not provided.
RUNNER_TOKEN	Runner token provided by GitHub in the Actions page. These tokens are valid for a short period.	Required if GITHUB_ACCESS_TOKEN is not provided
RUNNER_WORK_DIRECTORY	Runner's work directory	"_work"
RUNNER_NAME	Name of the runner displayed in the GitHub UI	Hostname of the container
RUNNER_REPLACE_EXISTING	"true" will replace existing runner with the same name, "false" will use a random name if there is conflict	"true"

Runner auto-update behavior

The GitHub runner (the binary) will update itself when receiving a job, if a new release is available. In order to allow the runner to exit and restart by itself, the binary is started by a supervisord process.

Runner expectations

This modified version of docker-github-runner is intended to be run under kubernetes. It writes the acquired runner token to /runner/token for later use in deprovisioning. It expects a volume mounted at /runner to exist, and will write its runner registration token to /runner/token for use in deprovisioning the runner.