index.js

const express = require('express')
const app = express()
const server = require('http').Server(app)
const net = require('net')
const pty = require('node-pty')
const WebSocket = require('ws')

app.use('/', express.static('.'))
const wss = new WebSocket.Server({ server })

wss.on('connection', ws => {
  ws.send('Hi there, I am a WebSocket server')
  let ptyProcess = pty.spawn('bash', ['--login'], {
    name: 'xterm-color',
    cols: 80,
    rows: 24,
    cwd: process.env.HOME,
    env: process.env
  })
  ptyProcess.on('data', data => ws.send(JSON.stringify({ output: data })))
  ws.on('message', message => {
    console.log('received: %s', message)
    m = JSON.parse(message)

    if (m.input) {
      ptyProcess.write(m.input)
    } else if (m.resize) {
      ptyProcess.resize(m.resize[0], m.resize[1])
    }
  })
})

server.listen(process.env.PORT || 8999, () => {
  console.log(`Server started on port ${server.address().port} :)`)
})