Well. That was some hard time to get that running.

These ways of building docker images with gitlab-runner(s) can be found online:

• just binding the docker executable into your build image and the socket
• using docker-in-docker (dind)
• using docker-in-docker with own entrypoint

But no one mentioned just using a bare gitlab-runner on your server with standard shell access and the gitlab-runner user added to the docker group. In the end it’s the simplest variant and the most obvious from my view but not the first propagated.

I tried the whole bunch mentioned above only to fail after hours of playing around, so I chose to get back to good oldschool gitlab-runner-without-docker and voila, everything runs smooth.