I was in the same position, wanted to set one up - decided it was too much work.
https://github.com/spantaleev/matrix-docker-ansible-deploy/
Been hosting it alongside some bridges(like irc) for a while now.
Shameless plug - for people who'd rather not maintain their own server manually with Ansible, a few others and I are running https://etke.cc - a completely FOSS service service built on top of the Ansible playbook. Hopefully, this provides the best of both worlds - ease of getting started (on your own or on a rented server), everything built on top of FOSS, no vendor-lock-in (you can migrate to using the playbook yourself at any time, etc.).
But you want sysadmin pain points, here are some random pointers in no particular order:
- Familiarity with reverse proxies helps a lot. I recommend terminating both client (443) and federation (8448) traffic through nginx or similar.
- The Synapse Github (https://github.com/matrix-org/synapse/issues) is one of the first places I start trawling if something gets weird.
- Federation is the second-hardest part, and if something goes wrong and you're not watching the Synapse logs it can fail silently - here it helps to have friends on other instances there to check connectivity (and blame you when THEIR instance breaks federation, that's fun). https://federationtester.matrix.org and similar help a lot too, and it's good to at least have a couple of bots from matrix.org to poke at if you suspect something's amiss.
- Fuck everything about troubleshooting STUN/TURN. Newer playbooks may make coturn deployment easier.
- It's easy to test migrations/deployments with an update to your hosts file - you can verify that your clients connect to the new server and that data has been restored without doing anything to the original server.
EDIT - Keep in mind that a lot of the above went on from 2018-2019 (except the server migration, but that was easy) and the documentation/automation has improved quite a lot since then.
I'm hosting a small set of services (Nextcloud in particular) for a group of friends, and the same thing is happening here. At some point, I added an email reset to my LDAP system so that people can reset their passwords themselves. I don't know how "normal" people live like that. I can't remember the last time I used a password reset other than for technical reasons.
Amusingly, two of my co-workers from a previous job also run their own homeservers, one a smaller private instance similar to mine and the other a single-user node that bridges many different chat systems together for personal use. The two of them also interact with the users on my homeserver on a regular basis in various public and private channels.
I should note that only one of the active users in the channels on my server is from matrix.org - everyone else is from the same server or federated instances run by other people. Matrix.org could go down tomorrow and things for us would mostly keep running just fine.
I do wish Synapse had a proper account invite system for private servers, and not the "spin up a matrix.org account and chuck the hapless fool in the hopefully-federated room" method that was there the last time I tried.