Support Github Enterprise Server

[eberkut]

Add support for Github Enterprise Server.

The API is usually nearly identical to github.com and in the context of this plugin, it's very likely to require no changes other than allowing to specify a base URL.

https://docs.github.com/en/enterprise-server@3.15/rest?apiVersion=2022-11-28
https://docs.github.com/en/enterprise-server@3.15/graphql

Authentication also usually works the same as github.com (including Github Apps, PAT, fine-grained PAT or device login).

[Paul-AUB]

Would be nice indeed, now Obsidian is usable freely even in enterprises !

[nathonius]

I think this is a great enhancement. However, it's going to require a bit more work than may be expected:

• Add option (per-account? globally?) to set a base API url
• Ensure all API calls use the base url configured for that account
  • If we cannot determine an account, what then?
• Currently a plain regex is used to decide if a link is a github link; with this change, we would have to run multiple different regexes, one for each account with a custom url as well as the default.
• Url parsing logic needs to be rewritten to not rely on the structure of the url before the actual REST path
  • For example, https://github.com/nathonius/obsidian-github-link/issues/169 is this issue on github, but if it was on a github enterprise server it could have any number of path segments before nathonius/obsidian-github-link...
• Do enterprise servers have different requirements for auth? Need to investigate.

[eberkut]

After a cursory review of the docs and from our experience, it seems that GitHub Enterprise Server URLs follow the same structure as those on GitHub.com or Enterprise Cloud—for example, see About remote repositories for Enterprise Server.

We also haven’t identified any significant differences in authentication between Enterprise Cloud and Enterprise Server (e.g. both support GitHub Apps, PATs, fine-grained PATs as outlined in the docs).

Based on this, I think an initial implementation could simply allow a configurable base URL for Enterprise Server without modifying the URL parsing logic for extra path segments. This could be revisited and refined later if needed.