Investigate why arm images contain x86 binaries

[sveitser]

Not a very high priority as the images still work on ARM macs but it seems weird to me.

Currently affected are I think the docker image in this repo and the one built here:

https://github.com/EspressoSystems/arbitrum-token-bridge/blob/integration/.github/workflows/espresso-docker.yml

[Ayiga]

Do you know which binaries are x86?

[sveitser]

I think last time I checked the entire image was affected. Also noticed during the docker build it looked like no arm image is actually being built. You don't observe this?

[sveitser]

There also seems to be only the amd64 builder invoked here: https://github.com/EspressoSystems/espresso-block-explorer/actions/runs/10353125028/job/28655279276 even though --platforms is passed to build on both architectures.

[Ayiga]

I'm not sure what you're seeing / looking at at the moment. In the link you provided, I only see this:

Which indicates that the job succeeded. If I look at the summary on that page, and I take a look at the build inputs, I see both architectures supplied:

context: .
file: ./docker/block-explorer.Dockerfile
labels:
  - org.opencontainers.image.created=2024-08-12T13:47:00.484Z
  - org.opencontainers.image.description=A repository for the Espresso Block Explorer Project
  - org.opencontainers.image.licenses=
  - org.opencontainers.image.revision=9eeeda9e2e9676865d1552460b777aee90d0a93c
  - org.opencontainers.image.source=https://github.com/EspressoSystems/espresso-block-explorer
  - org.opencontainers.image.title=espresso-block-explorer
  - org.opencontainers.image.url=https://github.com/EspressoSystems/espresso-block-explorer
  - org.opencontainers.image.version=pr-132
platforms:
  - linux/amd64
  - linux/arm64
tags:
  - ghcr.io/espressosystems/espresso-block-explorer:pr-132

That doesn't necessarily mean that the image is / will be arm64 / amd64, but it does look like it's trying to build both.

docker pull ghcr.io/espressosystems/espresso-block-explorer:main
docker inspect ghcr.io/espressosystems/espresso-block-explorer:main

On my local Mac it does seem to indicate that the image is an arm64 image:

{
...
        "Architecture": "arm64",
        "Os": "linux",
        "Size": 648259241,
...
}

So all of that looks like what I would expect more-or-less. But I'm not sure where you're seeing the x86 values come into play, and I want to make sure we're comparing / seeing the same thing.

[Ayiga]

So I attached an interactive shell to the resulting docker image:

docker run -it --rm --entrypoint=sh ghcr.io/espressosystems/espresso-block-explorer:main

And after installing file I inspected tini and node, and they both seem to not be arm64 files:

/app # which tini
/sbin/tini
/app # file /sbin/tini
/sbin/tini: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-musl-x86_64.so.1, BuildID[sha1]=a2e9d68ffa48ebf3d5c4917095ba70d378e92a06, stripped
/app # which node
/usr/local/bin/node
/app # file /usr/local/bin/node
/usr/local/bin/node: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-musl-x86_64.so.1, with debug_info, not stripped

[Ayiga]

node:alpine-20 itself does seem to have the correctly architected binary:

/ # which node
/usr/local/bin/node
/ # file /usr/local/bin/node 
/usr/local/bin/node: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-musl-aarch64.so.1, BuildID[sha1]=8fab97863a403efd8f8fb58c9294c9c278b6a72c, with debug_info, not stripped

[Ayiga]

Alright, at least in the case of the the block-explorer image the reason is due to this line here:

espresso-block-explorer/.github/workflows/docker.yml

Line 49 in 8cdc0ae

platforms: linux/amd64,linux/arm64 #arm64 timing out currently

Which was modified by @Ancient123 due to the arm64 job timing out.

[Ayiga]

Interesting.

ghcr.io/espressosystems/arbitrum-token-bridge:integration doesn't have that section commented out, but still has x86_64 binaries in the arm64 images. Which Is what this whole issue is about. Sorry it took me so long to get to what you were pointing out.

[Ayiga]

There's reference to this particular issue here:
docker/setup-buildx-action#183

which references this issue here:
actions/runner-images#2187

It seems that the platform passed is just the platform of the underlying runner's architecture.

I don't think we have any arm64 builders, otherwise we could perform the matrix strategy as proposed here:
https://docs.docker.com/build/ci/github-actions/multi-platform/

[Ancient123]

We have buildjet.com , you should be able to log on with your credentials for github. You can give those builders a try for ARM @Ayiga

[Ayiga]

We were able to determine that the linux/arm64 images contained linux/amd64 binaries due to the platform flag in the Dockerfile:

FROM --platform=$BUILDPLATFORM node:20-alpine AS builder

This setups the image to be built on the native platform of the runner, and exposes the BUILDPLATFORM as a native argument for cross compilation reasons. It does not indicate to the buildx platform which platform to build the image with.