Talk: PostgreSQL

The instructions are incomplete and lead to a system that never runs because it 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.