What is the best way to connect to socket.io?

Question

Nginx

Goodnight.

// подключение проходит на ура и по ws
let chat = io.connect('http://domain.ru:33333', {transports: ['websocket', 'flashsocket', 'xhr-polling']}); // (1)
// подключение отваливается, потому что пытается юзать ws
let chat = io.connect('http://domain.ru', {transports: ['websocket', 'flashsocket', 'xhr-polling']}); // (2)
// подключение по ws отваливается, и начинает работать по xhr-polling
let chat = io.connect('http://domain.ru'); // (3)

Everywhere they write that the problem is in crooked proxy servers.
I have the following nginx settings:

#...
location /socket.io/ {       
    proxy_pass http://localhost:33333;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";        
}
#...

Is the problem mine or somewhere on the side (and nothing can be done about it)?
(1) the option suits me perfectly, BUT sometimes non-standard ports are closed and then the client will not be able to connect ... can this be somehow bypassed?

Answer 1

Nginx is configured correctly, here is how to set up the server side
https://www.npmjs.com/package/socket.io
Here as a client side
https://www.npmjs.com/package/socket.io-client
Non-standard ports no need to use.