anchor.diff:        ];
         networking.extraHosts = ''
           ${config.networking.primaryIPAddress} example.com
  +        ${config.networking.primaryIPAddress} conference.example.com
  +        ${config.networking.primaryIPAddress} uploads.example.com
         '';
         networking.firewall.enable = false;
         services.prosody = {
  
positive.code:       environment.systemPackages = [
          (pkgs.callPackage ./xmpp-sendmessage.nix { connectTo = nodes.server.config.networking.primaryIPAddress; })
        ];
      };
      server = { config, pkgs, ... }: {
        nixpkgs.overlays = [
  
negative.code:         virtualHosts.test = {
            domain = "example.com";
            enabled = true;
          };
          muc = [
            {
              domain = "conference.example.com";
            }
          ];
          uploadHttp = {
            domain = "uploads.example.com";
          };
        };
      };
  