Postgresql's postmaster (Postgresql cluster [not cluster in the usual notion] manager), listens on TCP socket and also on UNIX domain socket (for localhost use only). Using UNIX doamin sockets to connect to Postgresql is very useful as it is bound to filesystem access only, no network socket involved. As a result, we get less overhead and less resource usage.
Often times we face the need to get our public IP address; in doing so, from time to time, we've used many URL endpoints, found in the wild - which seem to serve well for a while before disappearing suddenly, forever. As a permanent fix to this dilemma, i've written a tiny app and created couple of URL endpoints on my
BookShelfBD.com domain to get the public IP address and some HTTP request metadata over HTTP.