GitLab and GitLab CI setup

First, configure the environment parameters:

cp docker/gitlab/env.example.gitlab-gitlabci.txt docker/gitlab/gitlab-gitlabci.env
vi docker/gitlab/gitlab-gitlabci.env

Run the following command to start GitLab and a GitLab Runner in a Docker container:

docker compose -f docker/gitlab-gitlabci.yml --env-file docker/gitlab/gitlab-gitlabci.env up --build -d

Then log on to http://localhost/ with the password (sudo docker exec -it gitlab grep 'Password:' /etc/gitlab/initial_root_password) and go to http://localhost/admin/runners. Click on "Register an instance runner" and copy the registration token. Open a shell into the gitlab-runner container:

docker exec -it gitlab-runner /bin/bash

Execute the following command with your token inside the container with the registration token generated above (If you use Linux, try --clone-url http://172.17.0.1:80 \, because gateway.docker.internal is only for Windows):

gitlab-runner register \
  --non-interactive \
  --executor "docker" \
  --docker-image alpine:latest \
  --url http://gitlab:80 \
  --clone-url http://gateway.docker.internal:80 \
  --registration-token "PROJECT_REGISTRATION_TOKEN" \
  --description "docker-runner" \
  --maintenance-note "Just a random local test runner" \
  --tag-list "docker,artemis" \
  --run-untagged="true" \
  --locked="false" \
  --access-level="not_protected"

If you experience problems while installing or registering the runner, you can have a look at the documentation for docker (https://docs.gitlab.com/runner/install/docker.html, https://docs.gitlab.com/runner/register/index.html#docker)