Multiarch Docker image

[theBNT]

hi,

is it possible to create a multi-arch docker image by e.g. using buildx at

kubectl-gs/Makefile.gen.go.mk

Line 162 in 54b3ce6

docker build -t ${APPLICATION}:${VERSION} .

Maybe its sufficient to build via:

docker buildx build --platform=linux/amd64 -t ${APPLICATION}:${VERSION} .

Im using this image as a base-image for giantswarm/devctl#1047 and i get the warning on a windows system using docker desktop:

1 warning found:
 - InvalidBaseImagePlatform: Base image quay.io/giantswarm/kubectl-gs was pulled with platform "linux/386", expected "linux/amd64" for current build (line 1)
Base image platform does not match expected target platform

Probably linux/386 is some default but outdated anyway?

Looking at quay i could not find information regarding arch:

https://quay.io/repository/giantswarm/kubectl-gs/manifest/sha256:02c628b7245ec7cdd4e3618a7112026720a2c25f2e5f4c7371cced3c17953636

It also doesnt help to use --platform=${BUILDPLATFORM} in the Dockerfile or --platform=linux/amd64 in the commandline.

[ljakimczuk]

Hey @theBNT, it seems the linux/386 is your platform, for as far as I can tell, the kubectl-gs has already been built for the linux/amd64, you can check that by inspecting it after pulling like:

> docker inspect quay.io/giantswarm/kubectl-gs:latest
[
    {
        ...
        "Architecture": "amd64",
        "Os": "linux",
        ...
    }
]

I'm checking the possibility to leverage the multi-arch build to provide the linux/386.

[ljakimczuk]

@theBNT I updated the pipelines to build both, thelinux/amd64 and the linux/386 images, both going to be available from the next release onward.

[theBNT]

just as a quick feedback, build runs without errors now on my end, thanks a lot!