Signed-off-by: John Howard <jhoward@microsoft.com>
Addresses https://github.com/moby/moby/pull/35089#issuecomment-367802698.
This change enables the daemon to automatically select an image under LCOW
that can be used if the API doesn't specify an explicit platform.
For example:
FROM supertest2014/nyan
ADD Dockerfile /
And docker build . will download the linux image (not a multi-manifest image)
And similarly docker pull ubuntu will match linux/amd64
35193c0e7d