DataHUB: automate creation of gitlab runner

[Zalfsten]

Our DataHUB instance needs a gitlab runner for the CI/CD pipeline. Currently this runner is created as kubernetes pod by the helm chart. But it needs to be registered in gitlab. Currently this cannot be done via helm. The awkward workflow is:

• sync datahub application in argocd (or apply helm chart). This will setup datahub, but the gitlab runner setup will fail.
• Ask gitlab (either via web interface or API) for a gitlab runner registration token.
• Enter the token either into argocd directly or add it to the basic_infrastructure project.
• Sync datahub in argocd
• Now the gitlab runner should come up successfully.

There are gitlab runner operators available for kubernetes. Maybe they are able to offer a workflow compatible to helm/argocd. This should be tries out.