node koa 怎么监听 connet 请求，实现代理？

如果是要在一个 koa app 里面，拦截请求，转发到另一个服务，可以这样

const http = require('http');
const Koa = require('koa');
const net = require('net');

const app = new Koa();
app.use((ctx, next) => {
  ctx.body = 'from koa app';
});
const koaServer = http.createServer(app.callback()).listen(3000);
// const koaServer = app.listen(3000);

// proxy server
http.createServer((req, res) => {
  console.log(req.method);
  console.log(req.url);
}).listen(3001);

koaServer.on('connection', socket => {
  const proxy_socket = net.createConnection(3001)
  socket.on('data', chunk => {
    proxy_socket.write(chunk);
  });
  socket.on('end', () => {
    proxy_socket.end();
  })
});