NGINX Websockets, and SSL Configuration

Question

I'm trying to setup a websocket connection (wss). My domain uses ssl (certbot) and is powered by Nginx. I am unsure how to configure my /etc/nginx/sites-available/domain.com file.

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
...
}

I added the following into my config block:

location /websocket {
    proxy_pass         https://domain.com;
    proxy_http_version 1.1;
    proxy_set_header   Upgrade $http_upgrade;
    proxy_set_header   Connection "upgrade";
    proxy_set_header   Host $host;
}

When connecting via: wss://domain.com/, I am getting an error of

WebSocket connection to 'wss://domain.com/' failed: 
Error during WebSocket handshake: Unexpected response code: 200

Most of the examples out there are using a nodejs framework to serve their sites, but I am using php.

Answer 1

Your websocket endpoint is configured in the provided nginx configuration as hosted at the location /websocket within the server, but you are attempting to connect to the root URL wss://domain.com.

The websocket connection is an ordinary HTTP (with a TLS wrapper in this case) session until the upgrade takes place, so you must ensure the URL used to access the service includes all relevant path designators, e.g. wss://domain.com/websocket.