title: Jenkins: setting env variable from shell script
body: <p>I have a bash script that I execute from a Jenkins job, using "execute shell".
  The script starts an EC2 instance and sets an <code>host</code> variable containing the host name of the new instance.</p>
  
  <p>I would like to set the host name of the new instance (script variable: <code>host</code> ) to a Jenkins environment variable so that I can pass it down to a downstream job (possibly using the Build Flow plugin).</p>
  
  <p>Any idea how to do so?</p>
  
  <p>Thanks</p>