Why doesn't socket.io return connection on nuxt always 404?

Question

Node.js

so in nuxt I connect the plugin

plugins: [
    { src: '~/plugins/socket.io.js', ssr: false }
  ],

Errors are thrown into the console:

vendors.app.js:2332 GET localhost:3000/socket.io/?EIO=3&transport=polling&... 404 (OK)

When I connect the plugin like this, it still does not plow:

// plugins/socket.io.js
import Vue from 'vue';
import io from 'socket.io-client';
import VueSocketIOExt from 'vue-socket.io-extended';
 
const socket = io('http://localhost:3000');
 
export default ({ store }) => {
  Vue.use(VueSocketIOExt, socket, { store });
}

serve.js

import Koa from 'koa'
import { Nuxt, Builder } from 'nuxt'
import * as _io from 'socket.io'
import http from 'http'
import rootRouter from './routes'

const app = new Koa(),
      host = process.env.HOST || '127.0.0.1',
      port = process.env.PORT || 3000,
      server = http.createServer(app.callback()),
      io = _io(server)

io.on('connection', socket => {
  console.log('io Connected')
  socket.emit('newMessage', {
    text: 'WHAT'
  })
})

var start = async function() {
  const config = require('../nuxt.config.js')
  config.dev = !(app.env === 'production')
  const nuxt = new Nuxt(config)
  if (config.dev) {
    const builder = new Builder(nuxt)
    await builder.build()
  }
  app.use(rootRouter.routes()).use(ctx => {
    ctx.status = 200
    ctx.respond = false
    ctx.req.ctx = ctx 
    nuxt.render(ctx.req, ctx.res)
  })
  app.listen(port, host)
  console.log('Server listening on ' + host + ':' + port) 
}
start()

Answer 1

I was listening through the app and not through the server... For some reason it didn't bother me last time..
server.listen(port, host)