{
  network.description = "Web server";

  webserver =
    { config, pkgs, ... }:
    { services.httpd.enable = true;
      services.httpd.adminAddr = "alice@example.org";
      services.httpd.documentRoot = "${pkgs.valgrind.doc}/share/doc/valgrind/html";
      networking.firewall.allowedTCPPorts = [ 80 3000];

    services.hydra = {
       enable = true;
       hydraURL = "http://localhost:3000"; # externally visible URL
       notificationSender = "hydra@localhost"; # e-mail of hydra service
       # a standalone hydra will require you to unset the buildMachinesFiles list to avoid using a nonexistant /etc/nix/machines
       buildMachinesFiles = [];
       # you will probably also want, otherwise *everything* will be built from scratch
       useSubstitutes = true;
       #listenHost = "*";
    };



      #services.postgresql.enable = true;
      environment.systemPackages = with pkgs; [ wget vim git];


    };
}