socket-io-chat/index.js

const express = require('express');
const app = express();
const http = require("http");
const server = http.createServer(app);
const { Server } = require("socket.io");
const io = new Server(server);

app.get('/', (req, res) => {
	res.sendFile(__dirname + '/index.html');
});

io.on('connection', (socket) => {
	console.log('a new user connected');
	socket.on('disconnect', () => {
		console.log('user disconnected');
	});
	socket.on('chat message', (msg) =>{
		console.log('message: ' + msg);
		io.emit('chat message', msg);
	});

});

server.listen(3030, () => {
	console.log('listening on beaglebone.local:3030');
});