title: Ubuntu on Managed VMs using custom runtime
body: <p>Is it possible to deploy a managed vm with Ubuntu instead of Debian? I tried using:</p>
  
  <pre><code>FROM ubuntu:latest
  </code></pre>
  
  <p>at the top of the Dockerfile, but when it deploys and I ssh into from the compute engine console I still see Debian. I am know I am doing something wrong, my app.yaml file has what I think are the correct lines:</p>
  
  <pre><code>runtime: custom
  api_version: 1
  threadsafe: true
  vm: true
  </code></pre>
  
  <p>Thanks!</p>