distroless/base:debug doesn't work on Apple M1

[MrMYHuang]

Someones said Apple M1 doesn't support arm32:
https://news.ycombinator.com/item?id=27277351
However, Raspberry Pi 4 SoC supports both arm32 and arm64.

Container images claming with arm64 support but containing both arm32 and arm64 binaries DON'T work on Apple M1.
It seems that gcr.io/distroless/base:debug has the same problem.
On Ubuntu 21 arm64 on Parallels Desktop on Apple M1:

But on Ubuntu 20 arm64 on Raspberry Pi 4, it works well:

This problem causes some downstream images / apps won't work on Apple M1. For example, Tekton Pipeline:
https://github.com/tektoncd/pipeline/blob/dd3d0c24cd4870fce7d65ddc40a77d99fa8cab02/config/controller.yaml#L81

Please fix this problem. Thanks.

[MrMYHuang]

I find the problem comes from busybox:

distroless/busybox_archives.bzl

Lines 19 to 24 in 6028308

	http_file(
	name = "busybox_arm64",
	executable = True,
	sha256 = "141adb1b625a6f44c4b114f76b4387b4ea4f7ab802b88eb40e0d2f6adcccb1c3",
	urls = ["https://busybox.net/downloads/binaries/1.31.0-defconfig-multiarch-musl/busybox-armv8l"],
	)

The armv8l busybox binary is actually an arm32 one. I have sent a mail to busybox maillisting for help:
http://lists.busybox.net/pipermail/busybox/2022-February/089470.html

[loosebazooka]

Right, this is actually a dupe of #657, please update there.

[MrMYHuang]

Sorry, I find I was not very correct about the problem of distroless/base:debug with old armv8l busybox, because I find it works well on Docker on Apple M1. Please try this with Docker on Apple M1:

docker run -it gcr.io/distroless/base@sha256:cfdc553400d41b47fd231b028403469811fcdbc0e69d66ea8030c5a0b5fbac2b

However, it didn't work on Ubuntu 21 arm64 on Parallels Desktop on Apple M1. It would get this error

$ docker run -it gcr.io/distroless/base@sha256:cfdc553400d41b47fd231b028403469811fcdbc0e69d66ea8030c5a0b5fbac2b
standard_init_linux.go:228: exec user process caused: exec format error

Thus, the problem could not be what I said that was related to arm64 CPUs with no arm32 support.

Nevertheless, the arm64 busybox from docker-library does fix the "exec format error" problem on Ubuntu 21 arm64 on Parallels Desktop on Apple M1. Thus, the PR #960 is still meaningful.