XDT Transform not working for applicationHost.xdt on Azure - Environment variables are ignored

Question

It seems like environment variables are being ignored in my xdt transform for applicationHost.

I've created the following file applicationHost.xdt on azure in the \home\site folder. It does NOT perform the transform on applicationHost.config

<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">>
  <system.applicationHost>
    <applicationPools>
      <add name="%WEBSITE_SITE_NAME%" xdt:Locator="Match(name)">
        <recycling disallowOverlappingRotation="true" xdt:Transform="Insert" />
      </add>
      <add name="%WEBSITE_IIS_SITE_NAME%" xdt:Locator="Match(name)">
        <recycling disallowOverlappingRotation="true" xdt:Transform="Insert" />
      </add>
    </applicationPools>
  </system.applicationHost>
</configuration>

If I adjust the %WEBSITE_SITE_NAME% to say "dev-mysitename.com" the transforms work properly.

Why are the Environment variables not working properly? I need this to work so my different environments will work properly.

Answer 1

You cannot use Environment Variables like this. Its just not possible.