WebSocket connection failed: Error during WebSocket handshake: Unexpected response code: 400

Question

I am trying to integrate Socket.io with Angular and I\'m having difficulties making a connection from the client-side to the server. I\'ve looked through other related quest

Answer 1

The problem for me was not got the port from process.env.PORT it is very important because Haruko and other services properly do a random port numbers to use.

So that is the code that work for me eventuly :

var app = require('express')();
var http = require('http').createServer(app);
const serverPort = process.env.PORT ; //<----- important 

const io = require('socket.io')(http,{
  cors: {
    origin: '*',
    methods: 'GET,PUT,POST,DELETE,OPTIONS'.split(','),
    credentials: true
  }
});

http.listen(serverPort,()=>{
  console.log(`server listening on port ${serverPort}`)
})