When pulling an image by platform, it is possible for the image's
configured platform to not match what was in the manifest list.
The image itself is buggy because either the manifest list is incorrect
or the image config is incorrect. In any case, this is preventing people
from upgrading because many times users do not have control over these
buggy images.
This was not a problem in 19.03 because we did not compare on platform
before. It just assumed if we had the image it was the one we wanted
regardless of platform, which has its own problems.
Example Dockerfile that has this problem:
```Dockerfile
FROM --platform=linux/arm64 k8s.gcr.io/build-image/debian-iptables:buster-v1.3.0
RUN echo hello
```
This fails the first time you try to build after it finishes pulling but
before performing the `RUN` command.
On the second attempt it works because the image is already there and
does not hit the code that errors out on platform mismatch (Actually it
ignores errors if an image is returned at all).
Must be run with the classic builder (DOCKER_BUILDKIT=0).
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This enables image lookup when creating a container to fail when the
reference exists but it is for the wrong platform. This prevents trying
to run an image for the wrong platform, as can be the case with, for
example binfmt_misc+qemu.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
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
Since Go 1.7, context is a standard package. Since Go 1.9, everything
that is provided by "x/net/context" is a couple of type aliases to
types in "context".
Many vendored packages still use x/net/context, so vendor entry remains
for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
