Windows Container support in the Docker feeds?

I've been experimenting with the Docker feed functionality in ProGet to host Docker images. These images are built on Windows Containers, and while I didn't think that mattered, I'm seeing the following output when I try to push:

6414040ae497: Pushed
d4e75a41b2dc: Pushed
408403a891ac: Pushed
4029baf7c8ec: Pushed
74ef148425f5: Pushed
3fd27ecef6a3: Skipped foreign layer
manifest invalid: manifest invalid

I'm able to confirm that I can push regular Linux Docker images just fine; this is only an issue with the Windows Container images. I wouldn't have thought this to be an issue, but apparently it is. Are Windows Containers supported? If so, what needs to be done to push them to the Docker feed?

Product: ProGet
Version: 4.3.1

It should work, but we're still in the process of setting up a test environment for Windows Containers. We'll investigate this and get it working.

Is there an expected time frame of when that might be?

Unfortunately not; everything is still quite unstable (e.g. Docker client does not yet support Windows containers, unless you use a beta build), and everything on the implementation side of things is completely undocumented. Even the private registries from Dockers have issues support Windows containers it would seem...

If you're working with the Docker folks at Microsoft, or Windows folks at Docker, we'd love to get in touch and get a feel for their specifications so that we don't have to reverse engineer everything; thus we have not been able to get in touch with anyone via the partner engagement teams.

We will have full support for Windows containers in ProGet 4.7.10, which is scheduled for release tomorrow.