Comment by vdijkbas

I wrote a PR[1] for NixOS that adds a postage service. Just add the following to your configuration.nix to enable a postage web server:

  {
   services.postage = {
     enable = true;
     connections = {
       "local" = "hostaddr=127.0.0.1 port=5432 dbname=postgres";
     };
   };
  }

BTW the postage devs were very helpful in fixing packaging issues.

[1] https://github.com/NixOS/nixpkgs/pull/27796