I set up friendica as my first foray on to the fediverse. It worked well, but as it turns out doesn’t work that well with Lemmy, which was my main usecase. Well whilst trying to fix DNS issues setting up a Lemmy instance instead, I noticed my DNS logs were rather full. My Unbound DNS was getting 40k requests every 10 mins to *.activitypub-troll.cf. I don’t know who or what that is, but blocking it didn’t reduce the activity. At first I thought it was something to do with Lemmy as I’d forgotten I still had Friendica running. Thankfully stopping the Friendica service reduced the DNS request back to normal.
So if you’ve set something up recently, you might want to check if there have been any consequences in your service logs
While it’s true that their tutorial contains some errors, it’s not all that hard to set up imo.
Basically, they expose the wrong ports in the nginx section (should be 80, not the ui / backend ports). Also, the compose file assumes you are building the Lemmy image yourself, to change this, you have to comment out the lines in the “build” section under Lemmy and enable the “image” line. And you have to set the database user and pw in the Lemmy config file.
Regarding your usage of nginx: while I use apache myself, the config should be comparable and comes down to setting up a reverse proxy to the port which you have bound the nginx container to (so whatever you expose container port 80 as). While this means that you will effectively have two instances of nginx running, one as the internal proxy for Lemmy and one as the reverse proxy for external access, it will work flawlessly in my experience.