NGINX proxy to anycable websocket server causing "111: Connection refused" - nginx

Question

This is my NGINX config:
upstream app {
server 127.0.0.1:3000;
}
upstream websockets {
server 127.0.0.1:3001;
}
server {
listen 80 default_server deferred;
root /home/malcom/dev/scrutiny/public;
server_name localhost 127.0.0.1;
try_files $uri #app;
location #app {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://app;
}
location /cable {
proxy_pass http://websockets/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "Upgrade";
}
}
"app" is a puma server serving a Rails app, and "websockets" points to an anycable-go process as the backend for CableReady.
The Rails app is working fine, apart from the websockets.
The browser says:
WebSocket connection to 'ws://127.0.0.1/cable' failed:
And the NGINX error_log the following:
2021/07/14 13:47:59 [error] 16057#16057: *14 connect() failed (111: Connection refused) while connecting to upstream, client: 127.0.0.1, server: localhost, request: "GET /cable HTTP/1.1", upstream: "http://127.0.0.1:3001/", host: "127.0.0.1"
The websocket setup per se is working, since everything's fine if I point the ActionCable config directly to 127.0.0.1:3001. It's trying to pass it through NGINX that's giving me headaches.
All the documentation and advice I've found so far makes me believe that this config should do the trick, but it's really not.
Thanks in advance!

Answer 1

So the problem seemed to be the trailing slash in
proxy_pass http://websockets/;
Looks like it's working now.