title: How to use !FindInMap in !Sub | userdata section
body: <p>Currently I  am converting CFT from JSON to Yaml. Everything works fine until Userdata section.I am having hard time to use any of functions like !Ref or !FindInMap in userdata section.</p>
  
  <p><strong>UserData:</strong>    </p>
  
  <pre><code>Fn::Base64: !Sub |
          #!/bin/bash -v
          /command {Fn::FindInMap: [ "url", Ref: AWS::Region, Ref: EnvironmentType ] } 
  </code></pre>
  
  <p>It would be very helpful, If anyone can share any snippet of code.</p>