We use Varnish to serve a common header and footer for our site using ESI tags. These look something like:
<esi:include src="http://www.xyz.abc/esi_parts/footer" />
When discourse serveres the page back to Varnish it will inject the content into the page. However when we customize our theme (using the editor within the admin panel) and add the line above to the footer then on page load we see in the page source that its converted the above to:
Or sometimes (it seems random) it doesn’t show up in the page source at all.
Is there some parser that is mangling/removing it and if so how can we disable it or workaround it?