WebSocket connection to 'ws://…/socket.io/' failed: Error during WebSocket handshake: net::ERR_CONNECTION_RESET

Question

I am using nginx and proxying to my app that uses socket.io on node.js for the websocket connection.

I get the error above when accessing the app through the domain.

I have configured nginx according to https://github.com/socketio/socket.io/issues/1942 to ensure that websockets are properly proxied to the node.js backend.

My nginx configuration is below:

server {
    listen 80;
    server_name domain.com;

    location / {
        proxy_pass http://xxx.xx.xx.xx:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

In my react client, I start the websocket connection this way:

import io from 'socket.io-client';

componentWillMount() {
    this.socket = io();
    this.socket.on('data', (data) => {
        this.state.output.push(data);
        this.setState(this.state);
    });
}

Any advice is appreciated!

edit 1:

After more investigation.

My server set up is as follows:

Domain accessible from internet: web-facing.domain.com
Domain accessible from intranet: internal.domain.com

When I access the app from the intranet, it works fine, but get the error when accessing from the internet.

I suspect it's due to the creation of the socket using this.socket = io() which sets up a socket connection with the current domain.

Since the socket in node is listening to ws://internal.domain.com , when connecting via web-facing.domain.com, the wrong socket, ws://web-facing.domain.com , is created.

So now the question is, how can I create a socket to the internal domain when accessing from a different domain?

edit 2:

I have added app.set('trust proxy', true) to configure Express to accept proxy connections, but it still does not work.

Answer 1

Turns out there was another reverse proxy in front of my server that I had no control of. Changed my server set up to be directly internet facing and it works as expected.