Multi Architeture docker

[QuantumEntangledAndy]

In issue #73 we had a request for a docker image sutable for a raspberry pi (armhf architecture).

I looked into getting such an image to work on github actions. The solution was to build the docker with xbuild and qemu.

I went to the trouble of creating a multiarch build that supports all architectures that rust supports.

• amd64
• i386
• arm64
• armhf

It works in two stages:

• BUILD which runs on the host arch and cross compiles neolink (p.s. are there any archs that we should build for in the CI?)
• Publish which runs on the target arch using qemu which copies over neolink from the build machine.

I could not do this on alpine as that is amd64 only, so it is on debian buster. What I did was publish two tags

• :branchname which is the multiarch debian build
• :branchname-alpine which is the amd64 only alpine build

closes #73

[thirtythreeforty]

Thanks for looking at this.

It works in two stages:

• BUILD which runs on the host arch and cross compiles neolink (p.s. are there any archs that we should build for in the CI?)
• Publish which runs on the target arch using qemu which copies over neolink from the build machine.

I appreciate the attempt to use buildx; I think I would like to try to let someone else handle abstracting away the various platforms. I am concerned that the build/publish workflow might be tricky to maintain.

I did some looking into the bug you hit; seems it's something others are starting to hit. The root cause is based on a bad interaction with the Qemu 32-bit guest API and the host 64-bit ext4 kernel driver, which uses 64-bit inode numbers.

The workaround seems to be creating a small filesystem for Cargo's Git repo, which will prevent the host from using 64-bit inodes.

I think this should be possible to integrate with buildx, or with an Actions plugin like run-on-arch-action. What do you think?

[QuantumEntangledAndy]

I would certainly like to not have to cross compile too if possible. I will try the tmpfs route

mkdir ~/.cargo
mount -t tmpfs -o size=2048m tmpfs ~/.cargo

Then see how it goes

[QuantumEntangledAndy]

I have gotten it to build via tmpfs so the cross compile isn't needed anymore.
It supports the following

• amd64
• armhf
• arm64

Does not support

• armv6 (rasp pi 1)

We could probable do this all in alpine as pointed out in #84 which would make the armv6 maybe possible

[QuantumEntangledAndy]

@thirtythreeforty Probably ready for review when you have the time

[QuantumEntangledAndy]

With no progress on my PRs in years I am closing them in favour of working on my own fork. If your interested in these features please see there