Sinatra EC2 Deployment Security Group Error - ruby

Question

I am trying to deploy a Ruby Sinatra api onto port 4567 of an EC2 micro instance.
I have created a Security Group with the following rules (and created the instance with said security group):
--------------------------------
| Ports | Protocol | Source |
--------------------------------
| 22 | tcp | 0.0.0.0/0 |
| 80 | tcp | 0.0.0.0/0 |
| 443 | tcp | 0.0.0.0/0 |
| 4567 | tcp | 0.0.0.0/0 |
--------------------------------
I bound myapp.rb on port 4567 (the default, but for verbosity):
set :port, 4567
and ran the service:
ruby myapp.rb
[2013-09-05 03:12:54] INFO WEBrick 1.3.1
[2013-09-05 03:12:54] INFO ruby 1.9.3 (2013-01-15) [x86_64-linux]
== Sinatra/1.4.3 has taken the stage on 4567 for development with backup from WEBrick
[2013-09-05 03:12:54] INFO WEBrick::HTTPServer#start: pid=1811 port=4567
Used nmap while ssh'd in the EC2 instance on localhost:
Starting Nmap 6.00 ( http://nmap.org ) at 2013-09-05 03:13 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.00019s latency).
PORT STATE SERVICE
4567/tcp open tram
Nmap done: 1 IP address (1 host up) scanned in 0.08 seconds
Used nmap while ssh'd in the EC2 instance on the external ip:
Starting Nmap 6.00 ( http://nmap.org ) at 2013-09-05 03:15 UTC
Nmap scan report for <removed>
Host is up (0.0036s latency).
PORT STATE SERVICE
4567/tcp closed tram
Nmap done: 1 IP address (1 host up) scanned in 0.11 seconds
How do I change the state of the port from closed to open?

Answer 1

You’re starting Sinatra in the development environment. When running in development Sinatra only listens to requests from the local machine.
There a few ways to change this, the simplest is probably to run in the production environment, e.g.:
$ ruby myapp.rb -e production
You could also explicitly set the bind variable if you wanted to keep running in development:
set :bind, '0.0.0.0' # to listen on all interfaces

Answer 2

There are two possible causes for your problem.
Your service is only listening to connections on the loopback interface.
A software firewall is running and is blocking connections from outside on that port.