response.socket

• <stream.Duplex>

对底层套接字的引用。 通常用户不会想要访问这个属性。 特别是，由于协议解析器附加到套接字的方式，套接字将不会触发 'readable' 事件。 在 response.end() 之后，该属性为空。

const http = require('http');
const server = http.createServer((req, res) => {
  const ip = res.socket.remoteAddress;
  const port = res.socket.remotePort;
  res.end(`Your IP address is ${ip} and your source port is ${port}.`);
}).listen(3000);

该属性保证是 <net.Socket> 类（<stream.Duplex> 的子类）的实例，除非用户指定了 <net.Socket> 以外的套接字类型。

• <stream.Duplex>

Reference to the underlying socket. Usually users will not want to access this property. In particular, the socket will not emit 'readable' events because of how the protocol parser attaches to the socket. After response.end(), the property is nulled. The socket may also be accessed via response.connection.

const http = require('http');
const server = http.createServer((req, res) => {
  const ip = res.socket.remoteAddress;
  const port = res.socket.remotePort;
  res.end(`Your IP address is ${ip} and your source port is ${port}.`);
}).listen(3000);

This property is guaranteed to be an instance of the <net.Socket> class, a subclass of <stream.Duplex>, unless the user specified a socket type other than <net.Socket>.