What is this warning:
I have enabled docker compose V2 and set export DOCKER_DEFAULT_PLATFORM=linux/amd64 as an env variable as I believe that this enables an emulation that allows the docker images to run on an Apple M1 chip.
I am new to docker and am wondering if this means that the emulation is working or if I have not configured something correctly?
The warning means that amd64 images have poor performance, and sometimes crashing behavior as well. This is a known issue with Docker + qemu on the Apple Silicon chips. For this reason, Docker recommends avoiding use of amd64 images when possible.
https://docs.docker.com/desktop/mac/apple-silicon/
Not all images are available for ARM64 architecture. You can add --platform linux/amd64 to run an Intel image under emulation. In particular, the mysql image is not available for ARM64. You can work around this issue by using a mariadb image.
However, attempts to run Intel-based containers on Apple silicon machines under emulation can crash as qemu sometimes fails to run the container. In addition, filesystem change notification APIs (inotify) do not work under qemu emulation. Even when the containers do run correctly under emulation, they will be slower and use more memory than the native equivalent.
In summary, running Intel-based containers on Arm-based machines should be regarded as “best effort” only. We recommend running arm64 containers on Apple silicon machines whenever possible, and encouraging container authors to produce arm64, or multi-arch, versions of their containers. We expect this issue to become less common over time, as more and more images are rebuilt supporting multiple architectures.
