title: Automating wildcard subdomain for users GAE
body: <p>I have an app engine instance project under let's say: <code>cloud.domain.com</code></p>
  
  <p>My goal is to be able to give a user of my a unique url that they can then map to their own domain using a CNAME record. Basically how you would connect to a <a href="https://support.squarespace.com/hc/en-us/articles/205812378-Connecting-a-domain-to-your-Squarespace-site#toc-step-5---add-the-first-cname-record">domain to a squarespace account</a>.</p>
  
  <p>It could really be anything like so:</p>
  
  <pre><code>userid.cloud.domain.com
  userid.domain.com
  </code></pre>
  
  <p>Is this even possible with GAE? I've researched <a href="https://cloud.google.com/appengine/docs/php/console/using-custom-domains-and-ssl#wildcard_mappings">wildcard mappings</a> but there really isn't any solid advice on the topic.</p>
  
  <p>Is this even possible or should I look elsewhere to accomplish this kind of task?</p>