title: Setting environment variables in cloudformation using command module within cfn-init
body: <p>I'm trying to set environment variables through the commands module within cfn-init.</p>
  
  <pre><code>"commands": {
                "set-env": {
                  "env": {
                    "HOSTNAME": "fb-iaas.elevatebilling.com"
                  },
                  "cwd": "~",
                  "command": "echo \"$HOSTNAME\" &gt; test.txt"
                }
              },
  </code></pre>
  
  <p>And this is the output I see in cfn-init.log</p>
  
  <pre><code>2016-09-22 10:26:53,638 DEBUG Running command set-env
  2016-09-22 10:26:53,639 DEBUG No test for command set-env
  2016-09-22 10:26:53,655 INFO Command set-env succeeded
  2016-09-22 10:26:53,655 DEBUG Command set-env output: 
  </code></pre>
  
  <p>But environment variable HOSTNAME doesn't get updated. Can someone please explain what am I doing wrong?</p>
  
  <p>Thanks</p>