title: Rails: how to get the current host, or build a URL with it?
body: <p>I need to use the host to build a URL with a different port.</p>
  
  <p>For example, if the host is example.com, I need to generate a URL like <a href="http://example.com:8080/">http://example.com:8080/</a></p>
  
  <p>I need it to be portable, so when I'm in my local enviroment it shows <a href="http://localhost:8080/">http://localhost:8080/</a> instead.</p>
  
  <p>Any ideas?</p>