code: def daemonize(self):
          
          try:
              pid = os.fork()
              if pid > 0:
                  # exit first parent
                  sys.exit(0)
          except OSError as e:
              self.logger.error("Fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
              sys.exit(1)
  
          # decouple from parent environment
          os.chdir("/")
          os.setsid()
          os.umask(0)
  
          # do second fork
          try:
              pid = os.fork()
              if pid > 0:
                  # exit from second parent
                  sys.exit(0)
          except OSError as e:
              self.logger.error("Fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
              sys.exit(1)
  
          # write pidfile
          atexit.register(self.delpid)
          pid = str(os.getpid())
          with open(self.pidfile,'w+') as f:
              f.write("%s\n" % pid)
  
          sys.stdout = LoggerProxy(self.logger.info)
          sys.stderr = LoggerProxy(self.logger.error)
docs: do the UNIX double-fork magic, see Stevens' "Advanced
          Programming in the UNIX Environment" for details (ISBN 0201563177)
          http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16