Node.js获取请求IP地址

function getClientIp(req) {
      return req.headers['x-forwarded-for'] ||
      req.connection.remoteAddress ||
      req.socket.remoteAddress ||
      req.connection.socket.remoteAddress;
};

这里综合考虑了反向代理的有可能影响IP地址判断的因素，得出一个正确的IP地址，需要传入请求req