Gitlab runner in airgaped environment


I’m running Gitlab and Gitlab runner as docker containers. The connection between both of them is successfully established.

I have created a basic .gitlab-ci.yml to test Docker executor for now only echo “Test”.

When I look in the log, this fails because the Gitlab runner is trying to pull from
The setup is running in an airgapped environment so no direct access to internet.

I can download the docker images via a nexus proxy repository with username/password.

How can I configure authentication when using gitlab-runner to configure the docker image to be used?