anchor.diff:  let
     cfg = config.services.graphite;
     writeTextOrNull = f: t: if t == null then null else pkgs.writeText f t;
  -
     dataDir = "/var/db/graphite";
  -
   in {
   
     ###### interface
  
positive.code:         GRAPHITE_STORAGE_DIR = "${dataDir}";
        };
        serviceConfig = {
          ExecStart = "${pkgs.pythonPackages.carbon}/bin/carbon-aggregator.py --debug --pidfile /tmp/carbonAggregator.pid start";
          User = "graphite";
          Group = "graphite";
        };
  
negative.code:         fi
        '';
        restartTriggers = [
          pkgs.python27Packages.graphite_web
          pkgs.python27Packages.waitress
        ];
      };
  
      environment.systemPackages = [
        pkgs.pythonPackages.carbon
        pkgs.python27Packages.graphite_web
        pkgs.python27Packages.waitress
      ];
  
  