Running Gitlab simultaneously on two domains
The problem So you have a Gitlab instance running and you are thinking about migrating it to a new domain, without breaking existing functionality (such as the registry, links in a broad, hard-to-batch-edit documentation etc.) What you will probably find after a bit of searching is this six year old feature request on the Gitlab issue tracker, from which you will quickly understand that this is not supported. So, what to do?...