anchor.diff:  { config, pkgs, ...}:
   let
     cfg = config.services.varnish;
  +
   in
   with pkgs.lib;
   {
  
positive.code:         default = false;
          description = "
            Enable the Varnish Server.
          ";
        };
  
  
negative.code:         chown -R varnish:varnish ${cfg.stateDir}
        '';
        path = [ pkgs.gcc ];
        serviceConfig.ExecStart = "${pkgs.varnish}/sbin/varnishd -a ${cfg.http_address} -f ${pkgs.writeText "default.vcl" cfg.config} -n ${cfg.stateDir} -u varnish";
        serviceConfig.Type = "forking";
      };
  
  