nodejs获取客户端IP Address

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

代码，第一段判断是否有反向代理IP(头信息：x-forwarded-for)，再判断connection的远程IP，以及后端的socket的IP。