access to runner from parent project in a fork?

Description

I have a project which has specific runners to process the build, running in a specific environment. I have collaborators who work on this project. I want them to be able to fork the project, develop, commit, and make merge requests against my parent project. I prefer not to give them direct commit access to the parent project.

For them to be able to test their builds, they need access to the runner that belongs to the parent project. I'm using gitlab.com, so I'm not an admin who can create shared runners.

It's too much to ask my collaborators to set up their own runners, they shouldn't have to do that.

At present, the only ways to allow other people to use my runner are:

• install a gitlab server myself, become administrator, and create shared runners
• grant my collaborators Developer or Master access, and have them commit directly to my repository, instead of using the fork/pull model which I prefer

Proposal

I would like to be able to give my collaborators access to my personal gitlab runner. This could sit somewhere in the permissions matrix, so I can choose whether Masters, Developers, or Reporters can use the runner.

Ideally, to enforce the fork/pull model, I'd grant most of my collaborators Reporter access to the repository, and allow them to use my runners from their forks.

There are of course security implications, which is why this needs to be a per-project controllable option, not a default that cannot be changed.