anchor.diff:  
           path =
             [ pkgs.sudo pkgs.vlan pkgs.nettools pkgs.iptables pkgs.qemu_kvm
  -            pkgs.e2fsprogs pkgs.utillinux pkgs.multipath_tools
  +            pkgs.e2fsprogs pkgs.utillinux pkgs.multipath_tools pkgs.iproute
  +            pkgs.bridge_utils
             ];
   
           exec = "${nova}/bin/nova-compute --flagfile=${novaConf}";
  
positive.code: 
          # `openssl' is required to generate the CA.  `openssh' is
          # required to generate key pairs.
          path = [ pkgs.openssl pkgs.openssh ];
            
          exec = "${nova}/bin/nova-api --flagfile=${novaConf}";
        };
  
      # `nova-objectstore' is a simple image server.  Useful if you're
  
negative.code: 
    config = mkIf cfg.enableSingleNode {
  
      environment.systemPackages = [ nova pkgs.euca2ools pkgs.novaclient ];
  
      environment.etc =
        [ # The Paste configuration file for nova-api.
  