title: ruby sinatra remote connection
body: <p>I'm trying to get hello world working remotely in sinatra:</p>
  
  <pre><code>require 'sinatra'
  
  get '/' do
    "hello world"
  end
  </code></pre>
  
  <p>locally it works fine:</p>
  
  <pre><code>curl localhost:4567
  hello world
  </code></pre>
  
  <p>but when I try to access it remotely, I get a 404 error.
  The server is visible; I have other web applications running just fine (but not on nonstandard ports). this is a near-stock ubuntu install so there aren't any iptables rules that would block access to port 4567. Is there something I'm missing? I've had difficulty googling this.</p>