NGinx forward websocket from 80 to websocket port - nginx

Question

I am using Nginx as a web host and proxy for a websocket running on the same device listening on port 8888. Trying to find a way to have nginx listen on 80 and forward the websocket requests to the internal port. Without exposing a new port to the outside. Is this even possible?
UPDATE:
This is my current configuration:
error_log /var/log/nginx/error_log.log warn;
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}
upstream websocket {
server localhost:8888;
}
server {
listen 80;
#listen [::]:80 default_server;
# SSL configuration
#
# listen 443 ssl default_server;
# listen [::]:443 ssl default_server;
#
# Self signed certs generated by the ssl-cert package
# Don't use them in a production server!
#
# include snippets/snakeoil.conf;
root /var/www/html/EncoderAdmin;
# Add index.php to the list if you are using PHP
index index.php index.html index.htm index.nginx-debian.html;
server_name _;
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
try_files $uri $uri/ =404;
auth_basic "Restricted Content";
auth_basic_user_file /etc/nginx/.htpasswd;
}
location /ws {
proxy_pass http://localhost:8888;
proxy_http_version 1.1;
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}
}
When I try to connect to it with ws://[address]/ws I get:
WebSocket connection to 'ws://[address]/ws' failed: Error during WebSocket handshake: Unexpected response code: 400

Answer 1

Yes, it's possible assuming you can distinguish the normal HTTP requests and the socket ones.
The simplest solution is to match the socket uri with location, for example all the requests to /ws will be redirected to localhost:8888, any other url to localhost:8889. Here it is an example of configuration
server {
server_name _;
location /ws {
proxy_pass http://localhost:8888;
# this magic is needed for WebSocket
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
}
location / {
proxy_pass http://localhost:8889;
}
}
You should also remember to bind the websocket server to localhost:8888 and not to 0.0.0.0:8888. This step is not needed but with it the original port is not exposed!