Build linux/arm64 docker images

[justjake]

The current docker images (example) are published only for linux/amd64.

On my M1 Macbook Pro, using these images tends to take 10-100x longer than using native ARM64 builds of Emscripten from homebrew. However, Homebrew will randomly upgrade my Emscripten version due to python changing or something.

It would be great to be able to use the EMSDK docker image for stability/reproducibility without suffering from super slow builds on my laptop.

It appears that CircleCI supports ARM, so perhaps all that's needed is adding an extra build variant for Dockerfile-related build jobs?

https://circleci.com/docs/using-arm/

[sbc100]

While I agree we should provide arm64 docker images, if you want a solution that works today you could just install emsdk the normal way on macOS. The emsdk binaries provided via emsdk install latest are built for arm64.

[radiantly]

@sbc100 I see containers for linux/arm64/v8 are now being built, but are suffixed with -arm64. Is there a specific reason for this or could we merge these?

[sbc100]

Ah yes it looks like this issue was fixed in #1231. I'm not sure why this issue was not auto-closed.

@radiantly I'm not sure what you mean by "Is there a specific reason for this or could we merge these". Is there something wrong with the -arm64 suffix?

[radiantly]

Thanks @sbc100 for the response. To clarify:

Say you have a Dockerfile that uses FROM emscripten/emsdk:4.0.10 that works fine when compiling on an amd64 platform. Now, to compile on arm64, the Dockerfile would need to be edited to add the suffix FROM emscripten/emsdk:4.0.10-arm64.

Instead, if images for both platforms were made available under the 4.0.10 tag (for example, see the ubuntu image), the right platform would be seamlessly picked (and if needed, could be specified with the --platform argument).

[sbc100]

I see so the tags don't need to be different? Would you be interested in sending a PR for that?

Looks like a simple update to remove the specific ARM64_IMAGE_TAG would do it?

Are you sure it won't clobber the x86 version?

[radiantly]

Sure, let me take a look at this over the weekend and open a PR. As long as we push the image correctly I don't see a reason for the existing amd64 version to be affected.