anchor.diff:  
         PidFile = ${pidFile}
   
  -      DBHost = ${cfg.dbServer}
  +      ${optionalString (cfg.dbServer != "localhost") ''
  +        DBHost = ${cfg.dbServer}
  +      ''}
   
         DBName = zabbix
   
  
positive.code: 
          description = "Zabbix server daemon";
  
          startOn = if cfg.dbServer == "localhost" then "started postgresql" else "filesystem";
          stopOn = if cfg.dbServer == "localhost" then "stopping postgresql" else "starting shutdown";
  
          preStart =
            ''
  
negative.code:         # just monitor `cat'.
          script =
            ''
              rm -f ${stateDir}/dummy
              mkfifo ${stateDir}/dummy
              cat ${stateDir}/dummy &
  