title: Netty as "proxy": outbound channel with different port number
body: <p>I implemented a middleware in Netty based on the HexDumpProxy example:</p>
  
  <pre><code>BROWSER ------&gt; WEBAPP ------&gt; MW-NETTY ------&gt; SERVER
          [http]         [http]           [tcp]
  </code></pre>
  
  <p>Each customer has a dedicated WEBAPP but the MW-NETTY is a unique instance. The SERVER is listening to different port numbers, one per customer.</p>
  
  <p>From the MW-NETTY, how could I dynamically access the server, with the right port number, using an information in the HTTP header.</p>
  
  <p>As the channels are created before messages arrive, what would be the best strategy to implement it?</p>
  
  <p>Thanks,</p>
  
  <p>--nick</p>