bogus EADDRINUSE on web socket opening (nodeJS on a droplet)

Hello,

I have a nodeJS app which works fine locally. It listens to localhost:3001 for Http/web traffic, and then establishes a websocket connection on localhost:3002 for web sockets. Everything works fine when running locally, and the nginx proxy through to localhost:3001 works fine for the http connection.

The problem is the websocket connection. The statement const wsS = new WebSocketServer({ 3002, clientTracking: true }); works fine locally.

But on my Droplet it barfs with:

WSServer.e: {"code":"EADDRINUSE","errno":-98,"syscall":"listen","address":"::","port":3002}

I am sure that there is nobody else using that port - I can run this right after a machine reboot and get the error. also (thanks to an old support thread for this) “lsof -i:3002” shows nothing. And “pm2 list” also shows nothing.

So what’s it bitching about? :). Any attempt to then use that web socket fails. I’m getting the error running “node index.js” on the box without even pinging it from outside. I can ping the web server from outside, so I think the nginx proxying is ok, BTW.

Oh and here’s the ufw output:

To                         Action      From
--                         ------      ----
22/tcp                     LIMIT       Anywhere
Nginx Full                 ALLOW       Anywhere
OpenSSH                    ALLOW       Anywhere
80/tcp                     ALLOW       Anywhere
22/tcp (v6)                LIMIT       Anywhere (v6)
Nginx Full (v6)            ALLOW       Anywhere (v6)
OpenSSH (v6)               ALLOW       Anywhere (v6)
80/tcp (v6)                ALLOW       Anywhere (v6)

Thanks in advance!