Request for answers/documentation about binfmt

[justincormack]

The upstream for the Go binfmt code is https://github.com/linuxkit/linuxkit/tree/master/pkg/binfmt not here.

[justincormack]

1. yes this is shipped and automatically installed on Docker Dekstop for Mac and Windows
2. we do not support mips, probably docs need an update
3. this project is largely for Mac and Windows; generally we expect Linux users to use their distro provided versions or some other means of configuring.
4. there is no point in providing mips or mips64el as there are no Docker base images for those architectures. There might be some reason to provide arm32v6 but there have been no asks for it that I am aware of, all the binaries will generally run on arm32v7
5. Changing the target set is not a request we have had; users can re-register handlers if they know what they are doing.

[umarcor]

@justincormack, thanks a lot!

1. yes this is shipped and automatically installed on Docker Dekstop for Mac and Windows
2. we do not support mips, probably docs need an update

Should I open a PR somewhere else or will you track it on your own?

3. this project is largely for Mac and Windows; generally we expect Linux users to use their distro provided versions or some other means of configuring.

I understand that. However, I think it'd be good to add a reference in the docs. This sentence might be enough, along with some refs such as those listed as 'further info' in https://github.com/dbhi/qus#overview.

4. there is no point in providing mips or mips64el as there are no Docker base images for those architectures. There might be some reason to provide arm32v6 but there have been no asks for it that I am aware of, all the binaries will generally run on arm32v7

The use case is development of apps for devices such as RPi2. Although both arm32v6 and arm32v7 can run on armv7 (or armv8, i.e. aarch32) devices, the opposite will not work. Thus, images for arm32v6 hosts are required in order to build multiarch images that can run on RPi2.

Overall, providing targets such as armv6 or mips is meant for testing cross-compiled binaries (e.g. https://github.com/ASMImproved/qemu-mips-docker). Moreover, supporting armv6 as a host allows to avoid cross-compilation (just as it is now supported for aarch64).

5. Changing the target set is not a request we have had; users can re-register handlers if they know what they are doing.

The point is that I find it great for docker/binfmt to be written in golang, since it allows to distribute it as a static executable. I think that other users/projects could greatly benefit from it. Precisely, I think it might be interesting to enhance it with spf13/cobra and upstream it as an (optional) replacement for qemu-binfmt-conf.sh. wdyt?

[justincormack]

This repo is being deprecated in favourof https://github.com/linuxkit/linuxkit/tree/master/pkg/binfmt