There’s no forgetting where I have something hosted. If I ssh to service.domain.tld I’m on the right server. My services are all in docker compose. All in a ~/docker/service folder, that contains all the volumes for the service. If there’s anything that needed doing, like setting up a docker network or adding a user in the cli, I have a readme file in the service’s root directory. If I need to remember literally anything about the server or service, there’s an appropriately named text file in the directory I would be in when I need to remember it.

If you just want a diagram or something, there are plenty of services online that will generate one in ASCII for you so you can make yourself a nice “network topology” readme to drop in your servers’ home directory.