title: How can I view the contents of Varnish's hash_data()?
body: <p>I know that in Varnish you can add data to the cache hash using hash_data() within vcl_hash, as per the <a href="https://www.varnish-cache.org/docs/trunk/users-guide/vcl-hashing.html" rel="nofollow">docs</a>.</p>
  
  <p>For debugging purposes, I would like to be able to see the entire contents of whatever is making up the hash.</p>
  
  <p>For example, it would be really useful if we could do:</p>
  
  <pre><code> # This won't work:
   set req.http.X-DEBUG = "HASH-DATA:" + hash_data();
  </code></pre>
  
  <p>Does anyone know if this is possible?</p>