Hello,

It would be great to support "--from" like COPY but for ADD statement.
I build image in 2 separated images : 1 for compilation that output au rootfs archive, and another which ADD rootfs.tar as / from a scratch image.
I think that MSB is a good idea but ADD con't take "--from" parameter.

Sample Dockerfile used (https://gist.github.com/Zenithar/9209968).

Regards,