Can't access Node.js websocket service from Angular in production

Question

I'm facing a trouble while deploying a fullstack app into AWS EC2 instance.

I have my backend node.js app running on port 5000 I have my frontend Angular app handled by nginx on port 80 Both on the same instance.

I have managed to allow basics http calls but I didn't find the way to allow ws connection between my front and my backend.

Following code is the part I added in my nginx.conf file, in a server block, to allow communication between the 2 apps :

        listen       80;
        listen       [::]:80;
        server_name  _;

    #FRONTEND angular files
    location / {
        root /my_frontend_folder_path;
    }

    #BACKEND node/express proxy redirects
    location /api/ {
        proxy_pass http://localhost:5000/;
    }

    location /ws/ {
        proxy_pass http://localhost:5000/;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
    }

Angular side, here is how I connect to my websocket :

    this.socket = new WebSocket(ws://localhost:5000/ws);
    this.socket.onopen = () => {
      console.log('WebSocket connection established.');
    };

It works perfectly in my local machine but I got a "Connection refused" when I try to access it in my deployed app.

Apparently, the closest question I found here wasn't answered

I've tried different nginx conf that I found on web but none allows me to have a working service.

My expectation is to be able to connect to my websocket from my frontend hosted in the same instance.

EDIT : Finally I'm able to connect to my WS by changing his url client-side. I use the public IP address of my instance, I don't like this way but for now I just want to progress. But just after the connection is established successfully, it immediately closes with following error :

CloseEvent
bubbles: false
cancelBubble: false
cancelable: false
code: 1005
composed: false
currentTarget: null
defaultPrevented: false
eventPhase: 0
isTrusted: true
reason: ""
returnValue: true
srcElement: WebSocket {}
target: WebSocket {}
timeStamp: 482
type: "close"
wasClean: true

Any help would be very appreciated <3

Answer 1

Finally, I've found where was MY mistake...

nginx was "eating" a part of my url, so I've just added a '/ws' in my url...

this.socket = new WebSocket(ws://<INSTANCE_PUBLIC_IP>/ws/<NORMAL_WS_SERVER_ENDPOINT>);

Hope my brainless issue will help someone in the future xD