add build-arg ARCH

[andyzhangx]

this PR is for kubernetes-csi/csi-driver-nfs#166 to build multi-arch images
original error:

#7 [3/3] RUN apt update && apt install ca-certificates mount nfs-common nfs...
#7 0.115 /bin/sh: Invalid ELF image for this architecture
#7 ERROR: executor failed running [/dev/.buildkit_qemu_emulator /bin/sh -c apt update && apt install ca-certificates mount nfs-common nfs-kernel-server -y || true]: exit code: 255

https://prow.k8s.io/view/gcs/kubernetes-jenkins/logs/post-csi-driver-nfs-push-images/1363278699297771520

Does this PR introduce a user-facing change?:

none

[andyzhangx]

/release-label-none

[andyzhangx]

/release-label none

[pohly]

Why is this only relevant for the csi-driver-nfs? Can it break some other project when we merge this?

[andyzhangx]

Why is this only relevant for the csi-driver-nfs? Can it break some other project when we merge this?

@pohly nfs Dockerfile add nfs package which is distro relevant, --build-arg a=b just add a new arg for Dockerfile, if ARG a does not exist in Dockerfile, it just ignore and won't break.

• csi-driver-nfs Dockerfile

ARG ARCH
FROM k8s.gcr.io/build-image/debian-base-${ARCH}:v2.1.3
...

Add an ARCH in build arg is necessary since not all CSI drivers could use gcr.io/distroless/static:latest base image since some CSI drivers needs to install some packages which is distro relevant

[pohly]

That explanation makes sense. Can you put it into the commit message?

[andyzhangx]

That explanation makes sense. Can you put it into the commit message?

done, I set commit msg like this:

add build-arg ARCH for building multi-arch images, e.g. …

ARG ARCH
FROM k8s.gcr.io/build-image/debian-base-${ARCH}:v2.1.3

[pohly]

This is not how commit messages are normally written (https://chris.beams.io/posts/git-commit/), but okay.

[pohly]

/lgtm

[pohly]

/approve

[k8s-ci-robot]

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