Gitlab-runner + Docker + Windows - Invalid volume specification

At the moment there isn't official support for the Docker executor in Windows. A work in progress issue is open at the moment, and it looks like some people have managed to get a windows docker executor working to varying success in that merge request.

This specific comment shows how they've managed to get it setup using a custom built gitlab-runner. I'm unsure how this will work with Services however, so YMMV.

Docker is not fully supported by GitLab Runner on Windows yet. The workaround is to use Windows Subsystem for Linux and install gitlab-runner there:

curl -L https://packages.gitlab.com/install/repositories/runner/gitlab-runner/script.deb.sh | sudo bash
sudo apt-get install gitlab-runner
gitlab-runner exec docker build