title: filter outgoing requests in node.js for logging
body: <p>I am building an Express app which on certain requests has to make its own HTTP calls. I could use Superagent, request or node's own <code>http.request</code>.
  Thing is, I need to log all of those server originating requests and their respective responses. Calling <code>log.info</code> before each and every of those seems silly.</p>
  
  <p>How can you add a pre-filter for all outgoing HTTP calls, and ideally access both <code>req</code> and <code>res</code>?</p>
  
  <p><strong>NOTE:</strong> I am not interested in logging requests coming in to the server I am building, only in the requests that the server itself kicks off. Think of my server as a client to another black box server.</p>