title: How can I convert a Docker image into a (vagrant) VirtualBox box?
body: <p>I've been looking at Packer.io, and would love to use it to provision/prepare the vagrant (VirtualBox) boxes used by our developers.</p>
  
  <p>I know I could build the boxes with VirtualBox using the VirtualBox Packer builder, but find the layer stacking of Docker to provide a much faster development process of the boxes.</p>
  
  <p>How do I produce the image with a Dockerfile and then export it as a Vagrant box?</p>