Cannot access AWS EC2 server from localhost (curl times out)

I'm trying to proxy a node.js server with an ngnix. My issue is that I can't access (curl nor nginx) my node.js server on localhost,

When opening its 3000 port to the exterior, I can see my node js server running. But curl and nginx cannot access it.

One weired thing is that we have a mongodb started and that one can be accessed on localhost without any issues

My instance id is the following : i-0fef394cbc350a4f4

Here's the link to the nginx server that cannot find localhost and therefore times out : http://ec2-54-246-136-64.eu-west-1.compute.amazonaws.com/

I cannot find another way to demonstrate that we cannot access curl localhost:3000

var sticky = require("socketio-sticky-session");
sticky(function () {
  // This code will be executed only in slave workers

  var http = require('http');
  var socketIO = require('socket.io');

  var server = http.createServer(app);

  var io = socketIO(server);
  require('./app_api/config/socketio')(io);

  io.on('connection', (socket) => {
    log.trace("new user connected");
    socket.on('disconnect', () => {
      log.trace("user disconnected");
    });
  });
  connectToDispatcher();

  process.title = "share_place";

  return server;
}).listen(3000, function () {
      console.log((cluster.worker ? 'WORKER ' + cluster.worker.id : 'MASTER') + '| PORT ' + 3000)

      app.domain.on('error', (er) => {
        log.error('error', er.stack);

        try {
          // make sure we close down within 30 seconds
          var killtimer = setTimeout(() => {
            process.exit(1);
          }, 30000);
          // But don't keep the process open just for that!
          killtimer.unref();

          // stop taking new requests.
          server.close();

          // Let the master know we're dead.  This will trigger a
          // 'disconnect' in the cluster master, and then it will fork
          // a new worker.
          cluster.worker.disconnect();

          // try to send an error to the request that triggered the problem
          res.statusCode = 500;
          res.setHeader('content-type', 'text/plain');
          res.end('Oops, there was a problem!\n');
        } catch (er2) {
          // oh well, not much we can do at this point.
          log.error('Error sending 500!', er2.stack);
        }
      });

    }
);

An even more weired situation : we installed the node code on a beanstalk instance.

We access the node server from the outside : http://share-place.eu-west-1.elasticbeanstalk.com:8081/

But the default nginx from amazon replies with a connection refused message (for public resources that we can access from the outside)

/var/log/nginx/error.log

2017/04/21 14:32:19 [warn] 3360#0: duplicate MIME type "text/html" in /etc/nginx/conf.d/00_elastic_beanstalk_proxy.conf:42 2017/04/21 14:37:48 [warn] 7358#0: duplicate MIME type "text/html" in /etc/nginx/conf.d/00_elastic_beanstalk_proxy.conf:42 2017/04/21 14:38:41 [error] 7362#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 41.226.2.5, server: , request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:8081/", host: "share-place.eu-west-1.elasticbeanstalk.com" 2017/04/21 14:38:41 [error] 7362#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 41.226.2.5, server: , request: "GET /favicon.ico HTTP/1.1", upstream: "http://127.0.0.1:8081/favicon.ico", host: "share-place.eu-west-1.elasticbeanstalk.com", referrer: "http://share-place.eu-west-1.elasticbeanstalk.com/" 2017/04/21 14:38:45 [error] 7362#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 41.226.2.5, server: , request: "GET / HTTP/1.1", upstream: "http://127.0.0.1:8081/", host: "share-place.eu-west-1.elasticbeanstalk.com"

Maybe you use net module that's why you can't make http request in some cases.

check if socketio-sticky-session use's the module net.createServer or http.createServer.