Nodejs和socket.io服务器端口冲突

Question

I have NodeJS app (which also serves the client), and I'm trying to implement real time communication between the client and the server, so I'm using socket.io for this.

I added the following code in my server.js file:

const app = express();

const server = http.createServer(app);
realtime.connect(server);
server.listen(3002, () => {
  console.log(`Listening on port 3002`)
});

but whenever I'm changing my nodejs code, the server crash:

Error: listen EADDRINUSE: address already in use :::3002

How I can fix this and avoid reloading the listen code of my socket.io server when browsersync reload my nodejs app?

Answer 1

You can run the socket server in a separate port. And also you can use separate functions as middleware for the authentication.

Here is a simple example

> index.js

import express from 'express';
import Socket from './socket';

const app = express();
const port = process.env.PORT || 3000;
const socketPort = process.env.SOCKET_PORT || 8001;
const io = require('socket.io')(socketPort);

// User Authentication
// app.use(verifyToken);

// Socket Authentication
// io.use(socketTokenVerification);
    
const socket = new Socket(io);
socket.modelLoaded();

app.listen(port, () => {
  log.info(`HTTP server is running 🚀 on port ${port}
Socket service running 🚀 on port ${socketPort}
Process Pid: ${process.pid}`);
});

> socket.js

export default class {
  constructor(io) {
    this.io = io;
    this.connections = {};  // should be updated on connect and disconnect
  }

  addConnection(socket) {
    // your code here
  }

  removeConnection(socket) {
    // your code here
  }

  socketDisconnect(socket) {
    // your code here
  }

  modelLoaded() {
    const { io, connections } = this;
    io.on('connection', socket => {
      addConnection(socket);
      // any code here
    });
  }
}