Websocket connection on Google Compute Engine using a custom domain name - node.js

Question

I have a websocket server (node.js) which runs fine on localhost and on a previous heroku deployment. I am now migrating to google compute engine and running into some issues.
The websocket handshake is failing returning a 301 error. As pointed out in this answer this can be due to the request going through front end servers that do not support a websocket connection and can be worked around by targeting ws://my_external_gce_ip directly. I am wondering if there is some load balancing configuration I can update so that I can address my backend using the custom domain name.
While I understand the problem, it seems to me that the domain should be resolved to the external ip after a dns lookup so I don't understand the constraint really.
Sorry if this is very obvious. I'm new to GCE and have been googling all day trying to get this. I will paste my code below as well as the NGINX config but I don't think either are particularly helpful as all works fine addressing using the IP
index.js:
/* requirements */
var bodyParser = require("body-parser");
const WebSocket = require("ws");
const http = require("http");
const express = require("express");
const port = process.env.PORT || 3000;
/*
server definition and config
*/
const app = express();
app.use(bodyParser.json());
const server = http.createServer(app);
/*
web socket stuff
*/
const webSocketServer = new WebSocket.Server({
server,
});
webSocketServer.on("connection", (webSocket) => {
console.log("board trying to connect...");
webSocket.on("message", (data) => {
webSocketServer.clients.forEach((client) => {
if (client === webSocket && client.readyState === WebSocket.OPEN) {
client.send("[SERVER MESSAGE]: You are connected to the server :)");
}
});
});
});
/*
activate server
*/
server.listen(port, () => {
console.log(`Server is now running on port ${port}\n`);
});
nginx config
server {
listen 80 default_server;
listen [::]:80 default_server;
root /var/www/html;
index index.html index.htm index.nginx-debian.html;
server_name _;
location \ {
# we're actually going to proxy all requests to
# a Nodejs backend
proxy_pass http://localhost: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;
# I added this baby in
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
server
{
root /var/www/html;
index index.html index.htm index.nginx-debian.html;
server_name my_domain; # managed by Certbot
location / {
# we're actually going to proxy all requests to
# a Nodejs backend
proxy_pass http://localhost: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 $http_upgrade;
}
listen [::]:443 ssl ipv6only=on; # managed by Certbot
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/my_domain/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/my_domain/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}
server
{
if ($host = my_domain) {
return 301 https://$host$request_uri;
} # managed by Certbot
listen 80 ;
listen [::]:80 ;
server_name my_domain;
return 404; # managed by Certbot
}
Thanks very much in advance and sorry if this is a noob question. Total noob when it comes to load balancing

Answer 1

Solved. After a lot more googling I found this thread of people facing the same problem most either using apache servers or elastic beanstalk so not using nginx.
It seems that a lot of people get websockets to "work" using socket.io but they don't really have a duplex connection as it is falling back to long polling.
In my case the answer was simple, I didn't include the server name in my nginx (facepalm) and I may have forgot to include a header. The https forwarding now looks like this (and addressing using my domain works)
location / {
# we're actually going to proxy all requests to
# a Nodejs backend
proxy_pass http://localhost: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;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_read_timeout 90;
}
Don't forget to restart your nginx after you update
sudo systemctl restart nginx