glauth VS sqlightning

I would go with ldap server such as https://github.com/glauth/glauth. As for apps directly configure with ldap or add a proxy such as https://github.com/authelia/authelia

I was thinking about something along the lines of https://github.com/glauth/glauth - but that tool doesn't support the exact use case, I think. Are there any alternatives?

Another project, glauth: https://github.com/glauth/glauth. it's written in Go and has a declarative config--you can define users and groups in yaml. Makes it really easy to do HA etc.

I'm guessing you mean "and the software is fast enough", because OpenLDAP itself has been the world's fastest distributed database for over a decade, and nothing else even comes close.

Since you built on top of SQLite, then you're already at least an order of magnitude slower. You could speed it up a bit by using SQLightning, which replaces SQLite's Btree engine with OpenLDAP's.

https://github.com/LMDB/sqlightning

This has been shared without context but I guess the SQLite team is starting to modularize the btree code in order to facilitate work like SQLightning: https://github.com/LMDB/sqlightning

At the time SQLightning greatly improved SQLite performance but due to LMDB's requirement to have keys fit in 2/3 of a page it wasn't really useful as a general purpose replacement of SQLite's internal b-tree implementation.