Relation between linux/arm64 and linux/arm64/v8: are these aliases for each other?

Question

I have a question about the architecture of docker images.

For example, alpine:latest provides the image for linux/arm/v8 architecture. We can pull this image by specifying the linux/arm64 platform:

$ docker pull --platform linux/arm64 alpine
$ docker image inspect alpine
...
        "Architecture": "arm64",
        "Variant": "v8",
        "Os": "linux",
...

I figured out that this result implies linux/arm64 is an alias for linux/arm64/v8. In another experiments, I found the following similar behaviors:

• --platform linux/arm/v8 pulls linux/arm64 image
• --platform linux/arm pulls linux/arm/v7 image
• --platform linux/arm/v7 pulls linux/arm image

Could you please explain the definition of such aliases, or the rules for resolving the architecture? Or is there an official guide?

Thanks.

Answer 1

The Docker documentation has this list:

Architectures other than amd64?

Some images have been ported for other architectures, and many of these are officially supported (to various degrees).

    Architectures officially supported by Docker, Inc. for running Docker: (see download.docker.com)
        ARMv6 32-bit (arm32v6): https://hub.docker.com/u/arm32v6/
        ARMv7 32-bit (arm32v7): https://hub.docker.com/u/arm32v7/
        ARMv8 64-bit (arm64v8): https://hub.docker.com/u/arm64v8/
        Linux x86-64 (amd64): https://hub.docker.com/u/amd64/
        Windows x86-64 (windows-amd64): https://hub.docker.com/u/winamd64/
    Other architectures built by official images: (but not officially supported by Docker, Inc.)
        ARMv5 32-bit (arm32v5): https://hub.docker.com/u/arm32v5/
        IBM POWER8 (ppc64le): https://hub.docker.com/u/ppc64le/
        IBM z Systems (s390x): https://hub.docker.com/u/s390x/
        MIPS64 LE (mips64le): https://hub.docker.com/u/mips64le/
        RISC-V 64-bit (riscv64): https://hub.docker.com/u/riscv64/
        x86/i686 (i386): https://hub.docker.com/u/i386/