List all places where a repo is used as a submodule (on the same gitlab instance)
We run our own gitlab ee instance, where we host a couple of hundred repositories. Some of these projects have interdependencies. This means we have libraries, common code, etc. which we develop in repository A and use in application repository B, C, E, F. To keep track of changes and not have error-prone manual copying involved we use submodules to include the libraries in the application repository. That way the app developer can simply check for updates of the submodules they are using and decide to update. Easy enough.
But there's no link the other way around. The library developer has no (easy) way to figure out who is using their code and to e.g. use this information to check if an upcoming change might affect their userbase or to alarm everyone who is using the code of a breaking change, security update etc.
(of course there are other solutions to this, like keeping a separate mailing list, or using issue mentions, etc.)
Gitlab already supports submodules and displays them in the UI with a link to the referenced rpository and the referenced commit. This should be extended to have the parent repo A display every other repository listing it as a submodule within the local gitlab instance.
graph TD; RepositoryB-- src/subrepos/A -->SubmoduleA; RepositoryC-- src/subrepos/A -->SubmoduleA;
graph TD; SubmoduleA-- list all repos -->RepositoryB; SubmoduleA-- list all repos -->RepositoryC;
Links / references
I haven't found any, besides maybe packet managers which do similar things but none (I'm aware of) that do it for git.