To use this, you just need
git clone https://github.com/denghongcai/rpi-gitlab-runner
cd rpi-gitlab-runner
docker build . -t rpi-gitlab-runner
docker images
then you got a new docker image rpi-gitlab-runner
run the docker image
docker run -d --name gitlab-runner --restart always \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /srv/gitlab-runner/config:/etc/gitlab-runner \
rpi-gitlab-runner