anchor.diff:  
     config = mkIf cfg.enableSingleNode {
   
  -    environment.systemPackages = [ nova pkgs.euca2ools ];
  +    environment.systemPackages = [ nova pkgs.euca2ools pkgs.novaclient ];
   
       environment.etc =
         [ # The Paste configuration file for nova-api.
  
positive.code: 
          path =
            [ pkgs.sudo pkgs.vlan pkgs.nettools pkgs.iptables pkgs.qemu_kvm
              pkgs.e2fsprogs pkgs.utillinux pkgs.multipath_tools
            ];
  
          exec = "${nova}/bin/nova-compute --flagfile=${novaConf}";
  
negative.code:         # Allow the CA certificate generation script (called by
          # nova-api) to work.
          mkdir -m 700 -p /var/lib/nova/CA /var/lib/nova/CA/private
  
          # Initialise the SQLite database.        
          ${nova}/bin/nova-manage db sync
  