title: How to pass argument in packer provision script?
body: <p>I am struggling to pass input parameter to packer provisioning script. I have tried various options but no joy. </p>
  
  <p>Objective is my provision.sh should accept input parameter which I send during packer build.</p>
  
  <p>packer build -var role=abc test.json</p>
  
  <p>I am able to get the user variable in json file however I am unable to pass it provision script. I have to make a decision based on the input parameter. </p>
  
  <p>I tried something like </p>
  
  <pre><code>"provisioners": 
  {
    "type": "shell",
    "scripts": [
    "provision.sh {{user `role`}}"
   ]
  }
  </code></pre>
  
  <p>But packer validation itself is failed with no such file/directory error message. </p>
  
  <p>It would be real help if someone can help me on this.</p>
  
  <p>Thanks in advance.</p>