Getting the Office 365 Private CDN to work

After my big-ol' post yesterday (elsewhere in this thread) I've learned a few things and managed to get this to work with assets [haven't tried to host SPFx web parts yet, that's a task for tomorrow :) ].

The first thing I learned was that I need to pay attention to details when I read blog posts/documentation: it's pretty clear that this is a publishing feature and I didn't have the site collection and web publishing features enabled in my SPO dev site.  That's now taken care of.

Additionally, I realized that while the "https://dev.office.com/blogs/general-availability-of-office-365-cdn" post is a little unclear about it, I think the private CDN feature is still considered preview only at the moment.  I'm sure this will change soon, but in the mean time, I went to the settings page of my tenant-admin site and made sure that Preview Features setting was set to "Enable preview features".

The CDN now works everywhere I put the relative asset URL in a publishing page layout: in the page picture area, content area, even in a Content Editor Web Part where I have edited the HTML to have an <img> tag explicitly reference the item in the origin library.

Picture is now coming from the private CDN