Add ssh keys to host automatically

We have an automated process for building out new hosts for our kubernetes cluster. When we build out new hosts we need to clone a gitlab repo and run it. Is there an automated way to add the ssh keys to gitlab when a host is created. The gitlab server is self-hosted, the repo is private and the user does have access to clone, but not to push. What is the best way to do this?

In that case I would probably make something adding the SSH-keys through the users API, see: