title: How do I make a lib module method available project-wide and also specific to a class in Ruby on Rails?
body: <p>For example I would like to create a <code>current_server_host</code> method that returns the current host the application is currently running from.  </p>
  
  <p>lib/utility.rb:</p>
  
  <pre><code>module Utility
    def current_server_host
      request.env['HTTP_HOST']
    end
  end
  </code></pre>
  
  <p>How do I make it available project-wide where I don't need to include anything but can just call via  <code>Utility.current_server_host</code>?</p>
  
  <p>How do I make it specific to the class (model/controller/view) where I do need to call <code>include</code>?</p>
  
  <p>Please answer for RoR 3.2+.</p>
  
  <p>Thanks!</p>