Installation of Docker

https://docs.docker.com/engine/installation/linux/debian/

Install gitlab-ci-multi-runner

https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/blob/master/docs/install/linux-repository.md

Add gitlab-runner user to docker group:

# gpasswd -a gitlab-runner docker

Restart Docker service:

# service docker restart

Create a runner

Register a runner

# gitlab-runner register

Put the ...