Docker BuildX support Currently, when I build an AWS Lambda container compatible with AWS Graviton (arm64) it works fine on my laptop but GitHub Actions doesn't seem to support building arm64 images natively. A few people on blogs & forums seem to suggest that the workaround is to use the docker buildx action to build images, but that's incompatible with using

pulumi-docker

as a build system for the containers. Are there plans to support buildx in

pulumi-docker

? 🙏 @orange-policeman-59119 @shy-arm-32391 Also, if anybody has feedback struggling with arm images with their CI I'm happy to discuss it in this thread 🙂

It's supported in v4.

How so ? I thought the only

builderVersion

options where "BuilderBuildKit" and "BuilderV1" (vanilla docker)

BuilderBuildKit and BuildX share a common foundation, though it looks like more improvements are coming down the line for that functionality. You may need to install binfmt emulators to make cross platform builds work: https://github.com/tonistiigi/binfmt#installing-emulators

You can also explicitly specify the platform in the FROM directive in the Dockerfile if an image is only designed to be built for a single platform. https://docs.docker.com/engine/reference/builder/#from

But we do support setting the

platform

field to another architecture, just as Docker supports.

(Getting a single image to work with both arm and amd can be tricky, depending on what you're installing.)

I get what you're saying Josh but my based image was 100% arm64 and I did specify the

platform

argument to linux/arm64

Yes, unfortunately Docker does not yet have a multi-architecture API that is high level. We're waiting for improvements in Buildkit/BuildX.

The error I'm getting in GitHub Actions is:

exec /bin/sh: exec format error

With little more than that in terms of logging... but it does sounds to me like an arch mismatch somewhere

Perhaps, I'm only familiar with the

binfmt

install method. If you find that works, please let us know so we can update documentation!

Yup was gonna say exactly that 🙂