How to use the docker gitlab-runner to exec stages locally

I have setup a gitlab runner in docker on my local machine. It all is working fine. When the pipeline starts, the runner seems to handle the workload

But, I would like to do this locally. For example, if you downloaded the gitlab-runner executable, you can run stages locally

$> gitlab-runner exec docker  linting

But in my case I have the runner started in docker and I don't have the executable gitlab-runner. So my question is, is there a docker equivalent for this?

Solution

gitlab-runner exec works as its own standalone command and runs the job in the context of where the executable is called -- it will not cause the job to be run on a registered runner. It is solely a local operation, so you must have the binary available.

You can run gitlab-runner exec inside of your runner container or a new container if you want.

For example (assuming Linux platform):

docker run --rm \
       -v $(pwd):/workspace \ # mount directory to the container
       --workdir /workspace \ # set working directory
       -v /var/run/docker.sock:/var/run/docker.sock \ # enable docker
       --privileged \
       --entrypoint="gitlab-runner" \ # set entrypoint
       gitlab/gitlab-runner:latest exec docker MY_JOB

Or use doker exec to run the command on your existing container:

docker exec -it my-running-container-name gitlab-runner exec docker linting

Though, you will want to make sure the .gitlab-ci.yml file and project files are present in the container when you start it...