Pass platform constraint for oci layout

[giggsoff]

In case of oci layout FROM --platform= notation does not pass platform
constraint. In case of pointing onto digest of multi-platform index we
try to resolve target platform, which is wrong.

fixes #3396

Signed-off-by: Petr Fedchenkov giggsoff@gmail.com

[jedevc]

Good catch @giggsoff! I've been playing with the OCI layout code and didn't catch this one myself 😮‍💨

I can see similar logic implemented for docker-container, so I'm happy with the implementation 🎉

[deitch]

Thank you for the fix @giggsoff and the rapid merge @jedevc

[deitch]

@jedevc when does this end up in moby/buildkit? I am asking both in terms of a moby/buildkit image I can reference directly (i.e. that buildkitd will have this built-in, not just via # syntax=docker/dockerfile-upstream:master, and in terms of semver?

[jedevc]

Should be released in v0.11 - we've already done a release candidate RC1, we aim to do a full release soon.

Just a note, API compatibility won't necessarily be preserved between RCs and dev branches, we only have our API compatibility guarantees between our actual releases.

[deitch]

v0.11

Is there an ETA?

In the meantime, I probably can just use a reference to a specific digest, which is what I have done in the past.

API compatibility won't necessarily be preserved between RCs and dev branches, we only have our API compatibility guarantees between our actual releases

Hopefully, I haven't used anything that will break. If I do, we will fix it.

[deitch]

probably can just use a reference to a specific digest, which is what I have done in the past

Am I correct that this tag includes it?

[jedevc]

Is there an ETA?

When it's done 😉 Likely sometime this/next month, but can't say for sure.

Am I correct that this tag includes it?

Correct. Likewise with docker/dockerfile-upstream:master for frontend-side changes, like this one.

Hopefully, I haven't used anything that will break. If I do, we will fix it.

Any issues will likely be avoided by making sure that you don't mix and match development versions of buildx/buildkit/dockerfiles.

[deitch]

Cool, thanks.

Looks like it is moby/buildkit@sha256:daadc9f6dc5829c9dfa68ef9f4292c2d5b2fddf848046e02e43db53037373dda, which I can reference.

While on the topic, did the frontend ADD <git> ever make it into anything other than docker/dockerfile-upstream:master-lab?