code: def gunicorn_run():
      try:
          from gunicorn.app.wsgiapp import WSGIApplication
      except ImportError as exc:
          args = exc.args
          arg0 = args[0] if args else ''
          arg0 += ' (are you sure `gunicorn` is installed?)'
          exc.args = (arg0,) + args[1:]
          raise
      class PecanApplication(WSGIApplication):
          def init(self, parser, opts, args):
              if len(args) != 1:
                  parser.error("No configuration file was specified.")
              self.cfgfname = os.path.normpath(
                  os.path.join(os.getcwd(), args[0])
              )
              self.cfgfname = os.path.abspath(self.cfgfname)
              if not os.path.exists(self.cfgfname):
                  parser.error("Config file not found: %s" % self.cfgfname)
              from pecan.configuration import _runtime_conf, set_config
              set_config(self.cfgfname, overwrite=True)
              cfg = {}
              if _runtime_conf.get('server'):
                  server = _runtime_conf['server']
                  if hasattr(server, 'host') and hasattr(server, 'port'):
                      cfg['bind'] = '%s:%s' % (
                          server.host, server.port
                      )
              return cfg
          def load(self):
              from pecan.deploy import deploy
              return deploy(self.cfgfname)
      PecanApplication("%(prog)s [OPTIONS] config.py").run()