title: Passing user-data to EMR EC2 instances
body: <p>EC2 has a well documented way, in StackOverflow and on AWS, to providing UserData:</p>
  <ul>
  <li><a href="https://stackoverflow.com/questions/61902553/set-hostname-on-ec2-using-cloud-init-and-instance-tags">Set hostname on EC2 using cloud-init and instance tags?</a></li>
  <li><a href="https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html</a></li>
  </ul>
  <p>This allows developers to launch a script early in the machine's boot-up.</p>
  <p>However when launching an EMR cluster there doesn't appear to be support for passing along this kind of information. The next best thing would be creating one's own AMI but it would of-course be preferable to avoid that.</p>
  <p>My goal is to manually set the hostname of the EMR EC2 machines.</p>