I use authelia. It’s pretty straight forward to get started with, I just use the yaml user file and a SQLite database for sessions. I’m running it in podman with auto updates enabled for the tag I’m using (can’t remember which tag, but not latest).
I then use their tutorials as a base for the systems I want to use oidc with (grafana, miniflux…), or just redirect traffic through my reverse proxy to services that lacks proper authentication (looking at you, *arr stack).
I use caddy and traefik for reverse proxy, and it’s very simple to use forward_auth and similar with it.
It took an evening to figure it out but it’s well worth it!