Dead simple and has worked for me for years, now.

https://github.com/sabre-io/Baikal

I ran mine for a bit and it’s a resource hog, fragile, and images are a constant problem because the cache just keeps growing and growing so either you keep a limited timeframe of user images or you pay for storage elsewhere.

I was the only user so I didn’t have to deal with moderation, but what finally spooked me was the possibility of someone posting something illegal and it propagating over to my server. That was why I stopped hosting my Lemmy server, too.