Setup GitLab SaaS Runner

1. Start up a GitLab runner in docker by creating a docker-compose.yml file with the following:

   version: "3.7"
   
   services:
     gitlab-runner:
       image: gitlab/gitlab-runner:latest
       container_name: gitlab-runner
       volumes:
       - "./gitlab-runner/config:/etc/gitlab-runner"
       - "/var/run/docker.sock:/var/run/docker.sock"

2. Start up the container by typing docker-compose up. It is ok if you see error logs in the runner console; we will configure the token in the next step.
3. In GitLab; navigate to Project -> Settings -> CI/CD -> Runners. Copy the runner token.
4. Run this script replacing <<RUNNER TOKEN>> with the value you just copied

    #!/bin/bash
    docker exec -it gitlab-runner \
    gitlab-runner register \
        --non-interactive \
        --registration-token <<RUNNER TOKEN>> \
        --locked=false \
        --description docker-stable \
        --url https://gitlab.com \
        --executor docker \
        --docker-image openjdk:8 \
        --docker-volumes "/var/run/docker.sock:/var/run/docker.sock"
   

5. Refresh the GitLab Runner page; the runner should now be registered with a green status indicator.