papina/gitlab-runner repository overview

⁠Docker Compose

version: "3.7"
services:

  # Gitlab CI/CD can utilise Docker images with this running
  dind:
    image: docker:24-dind
    restart: always
    privileged: true
    environment:
      - DOCKER_TLS_CERTDIR=
      - DOCKER_HOST=tcp://0.0.0.0:2375
    command:
      - --storage-driver=overlay2
      - --tls=false

  # Register the GitLab Runner, and write to config.toml. Service not needed after this has run
  gitlab-register:
    image: gitlab/gitlab-runner:latest
    environment:
      - CI_SERVER_URL=${CI_SERVER_URL}            # Normally https://gitlab.com, change for Self-Hosted in .env
      - REGISTER_NON_INTERACTIVE=true             # Register without prompts
      - REGISTRATION_TOKEN=${REGISTRATION_TOKEN}  # This is the old way of registration, but here for backward compatibility
      - TOKEN=${TOKEN}                            # New way of registering Gitlab runners
    command: |
      register --token ${TOKEN} --executor docker --docker-image=docker:24-dind --docker-volumes=/var/run/docker.sock:/var/run/docker.sock
    volumes:
      - gitlab-runner:/etc/gitlab-runner

# Customised Runner image with some tools installed for Shell, and hook into the DIND service above
  gitlab-runner:
    restart: always
    image: papina/gitlab-runner:latest
    environment:
      - DOCKER_HOST=tcp://dind:2375
    volumes:
      - gitlab-runner:/etc/gitlab-runner

volumes:
  gitlab-runner:

⁠Service: dind

• Image: This service uses the "docker:24-dind" Docker image, which provides a Docker-in-Docker (DinD) environment.
• Restart: The service is configured to always restart automatically if it stops.
• Privileged: Setting "privileged" to true allows the service to run with additional privileges.
• Environment: The "DOCKER_TLS_CERTDIR" environment variable is set to an empty string, to disable TLS certificate for Docker.
• Command: The Docker daemon is launched with the "--storage-driver=overlay2" and "--tls=false" options

⁠Service: gitlab-register

A single run service that will create the config.toml file in the volume shared with the actual gitlab runner.

• Image: This service uses the gitlab/gitlab-runner:latest Docker image, which is used to register a GitLab Runner.
• Environment: Several environment variables are set, including
  • CI_SERVER_URL the GitLab server URL
  • REGISTRATION_TOKEN the legacy registration token
  • TOKEN the registration token
  • REGISTER_NON_INTERACTIVE is set to true to run the registration process non-interactively.
• Command: The service runs the "register" command to register the GitLab Runner with specific configurations, such as using the "docker" executor and the "docker:24-dind" image. It also specifies the Docker socket that will be available to the runner.
• Volumes: The service mounts the "gitlab-runner" volume into the container at "/etc/gitlab-runner"

⁠Service: gitlab-runner

• Restart: Like the "dind" service, this service is configured to always restart automatically if it stops.

• Image: This service uses the "papina/gitlab-runner:latest" Docker image, which is a customized GitLab Runner image with additional tools such as aws cli and ssm, terraform, and additional shell tools with the configurations.

• Environment: The "DOCKER_HOST" environment variable is set to "tcp://dind:2375," indicating that this GitLab Runner should communicate with the Docker daemon in the "dind" service.

• Volumes: The service mounts the "./gitlab-runner" directory into the container at "/etc/gitlab-runner."

• gitlab-runner: Shared volume, will have /etc/gitlab-runner/config.toml configured

This Docker Compose file is designed to create a Gitlab runner environment for GitLab CI/CD integration, including a Docker-in-Docker (DinD) service, a GitLab Runner registration service, and a customized GitLab Runner with specific Docker configurations and tools installed. The services are orchestrated to work together for automated CI/CD tasks, and allow for Gitlab Pipelines to be run locally without using Gitlab compute usage