title: Pass command line argument to vagrant shell script provisioner
body: <p>Similar to this question: <a href="https://stackoverflow.com/questions/15461898/passing-variable-to-a-shell-script-provisioner-in-vagrant">Passing variable to a shell script provisioner in vagrant</a></p>
  
  <p>I want to pass variables to a shell script provisioner but I want to set these variables on the command line when I call the provisioner. Is this possible?</p>