@jd For your own repos, I think the easiest way is to actually self-host Gitea, not GitLab.
You can run it with minimal resources, even on a Raspberry Pi 3
Then just go to https://dl.gitea.io/gitea and download the binary for your OS+architecture
Next, run the binary with ./gitea web
Open your browser on the URL + port it tells you
Configure with sqlite, so you don't have to maintain a database.
Enjoy!