Janus does not work on M1 Macs

[simon-friedberger]

ARM is currently not support by Janus so M1 Macs cannot be used for development.
I was looking for a way to get around that.

I have set up podman with qemu in such a way that images for other architectures can be run.

Specifically, I have done

podman machine init --cpus=4 --memory=8192 -v $HOME:$HOME
podman machine ssh
sudo rpm-ostree install qemu-user-static
sudo systemctl reboot

testing that it works with e.g.

podman run --rm -it docker.io/amd64/alpine 

At this point the janus build still fails. So I made a few changes to replace calls to docker with calls to podman and specifying --arch=aarm64 (docker doesn't have that argument). That makes the build work.

cargo test is still failing when trying to create the ephemeral DB. I probably won't pursue this further but maybe this is useful information to somebody. At least it's possible (if a bit slow) to build.

[divergentdave]

I looked into using podman a while back for other reasons, and there were a few incompatibilities between testcontaners-rs and it. The last one I identified was containers/podman#13803. If you're not using a bleeding edge of podman, that's probably the issue.

[tgeoghegan]

I don't think we should commit to supporting any target unless we can run our CI on it. I think we can just add latest macOS to our test matrix, but AFAICT Apple Silicon VMs are not yet available in GitHub Actions (actions/runner-images#2187, github/roadmap#528). The prior art I'm aware of for GHA on Apple Silicon involves running your own fleet of runners, which is not something I think we should commit to doing.

[inahga]

I've had success on my M3 Macbook with developing Janus both locally and containerized. @simon-friedberger, let me know if you're still having problems.

Note that I use Colima as my container VM, but this is largely a matter of taste.