Clojure app running only in tcp6 - websocket

Question

So I'm in over my head, but I nearly have a working Clojure app with WebSocket connection deployed to a prod-like environment, but there are a few things that I can't seem to work out. When I hit the endpoint with curl from localhost I get the response I was hoping for, so far so good. But when I try access it from my domain, I don't get a connection. When I checked netstat to make sure the port (8001) is open, I see the following:
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 3283/nginx: master
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 3218/sshd
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 3283/nginx: master
tcp6 0 0 :::8001 :::* LISTEN 3260/java
tcp6 0 0 :::80 :::* LISTEN 3283/nginx: master
tcp6 0 0 :::22 :::* LISTEN 3218/sshd
tcp6 0 0 :::443 :::* LISTEN 3283/nginx: master
I am running ufw but I already allowed the port, so I'm not sure if there is something I need to do when running the app to make it available as a normal tcp service? Or am I barking up the wrong tree?
Here is the command that is currently running:
java -jar test.jar 8001
Also I was torn between here and serverfault, but opted for stackoverflow because I think it's Clojure-centric. Please feel free to correct me.

Answer 1

looks like you have a good setup where nginx is providing a reverse proxy to your app, this is a solid way to go about it.
A tcp6 listener on :::8001 is likely also listening on ipv4 as well as ipv6 it just doesn't print both of them
At lest at a first glance it looks like nginx is missing a forward rule for /* to localhost:8001/*
they look something like this in ngins.conf
location ~ ^/.* {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_set_header X-Forwarded-Proto $fwd_proto;
proxy_redirect off;
proxy_pass http://localhost:8001;
}