Talk: PostgreSQL
From NixOS Wiki
The instructions are incomplete and lead to a systm that never runs because is missing the local part. This is what worked for me.
services.postgresql = { settings = { listen_addresses = "*"; }; enable = true; enableTCPIP = true; authentication = pkgs.lib.mkOverride 10 '' local all all trust host all all ::1/128 trust host all postgres 127.0.0.1/32 trust ''; };
if you just do the part that accepts TCP connections WITHOUT the local, it just doesn't run because it is missing it.