How to get websocket over SSL in Express app? - node.js

Question

After making my websocket work localy i deployed it and got security errors due to it not being over SSL. I am hosting a NodeJS Express app with Nginx and Certbot.
server.js
const express = require('express');
const app = express();
// unrelated imports
app.use(bodyParser.json());
app.use(cors());
app.use(express.static('public'));
app.use(bodyParser.json({ limit: '50mb' }))
require('./services/socket')(app)
// unrelated endpoints
app.listen(port);
socket.js
let WebSocket = require('ws');
module.exports = function(app) {
let ws_server = new WebSocket.Server();
ws_server.on('connection', (connection) => {
connection.on('message', (message) => {
ws_server.clients.forEach((client) => {
if (client.readyState === WebSocket.OPEN && client != connection) {
client.send(message);
}
});
});
});
}
Now the app is HTTPS but not the websocket, how can i get the socket to also use SSL/certs?

Answer 1

In such setup nginx needs to handle the SSL and be properly set up to work with web sockets. Here's an article from nginx blog NGINX as a WebSocket Proxy . The essential bits are:
location /wsapp/ {
proxy_pass http://wsbackend;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
proxy_set_header Host $host;
}
You might also want to set up timeouts for the connection.
And Express needs to trust the reverse proxy. Here's an article from them Express behind proxies
. If you are deploying in a secure environment you can just set it to app.set('trust proxy', ()=>true)
For reference here are the nginx timeouts I had to set up for my application:
proxy_connect_timeout 14d;
proxy_read_timeout 14d;
proxy_send_timeout 14d;