title: Referencing env variables from Elastic Beanstalk .ebextensions config files
body: <p>Is it posssible to reference the PARAM1 / PARAM2 etc.. container environment properties from the .ebextensions config files. If so, how? I tried $PARAM1 but it seemed to be an empty value.</p>
  
  <p>I want to set the hostname on startup to contain DEV, QA or PROD, which I pass to my container via the PARAM1 environment variable.</p>
  
  <pre><code>commands:
    01-set-correct-hostname:
      command: hostname myappname{$PARAM1}.com
  </code></pre>