How do you detect whether an image has arm support? Or how do you run arm images?

Docker Desktop for Mac
1

Can someone help me figure out how to determine whether an image has ARM support? I’m on an M1 Mac, using Docker Desktop 4.19.0 (106363).

I am able to run some ARM images fine:

$ docker run --platform linux/arm64 ubuntu:latest uname -a
Linux 955ea44909d5 5.15.49-linuxkit #1 SMP PREEMPT Tue Sep 13 07:51:32 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux

Others, many of which I expect to have arm64 support based on their documentation (Multi-platform images | Docker Documentation), such as busybox, fail with:

docker run --platform linux/arm64 busybox:latest uname -a
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
Digest: sha256:086417a48026173aaadca4ce43a1e4b385e8e62cc738ba79fc6637049674cac0
Status: Image is up to date for busybox:latest
WARNING: image with reference busybox was found but does not match the specified platform: wanted linux/arm64, actual: linux/amd64
docker: Error response from daemon: image with reference busybox:latest was found but does not match the specified platform: wanted linux/arm64, actual: linux/amd64.
See 'docker run --help'.

Running without the --platform argument returns:

$ docker run busybox:latest uname -a
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
Linux a1d670601cdd 5.15.49-linuxkit #1 SMP PREEMPT Tue Sep 13 07:51:32 UTC 2022 x86_64 GNU/Linux

When I run docker manifest inspect busybox:latest I do see an entry for arm64/v8.

      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 528,
         "digest": "sha256:1af0a016aaa24dd9ddf2ff0771160a68d6394eff88c9c0d5239c93a21ea06f9f",
         "platform": {
            "architecture": "arm64",
            "os": "linux",
            "variant": "v8"
         }

Running docker run --platform linux/arm64/v8 busybox:latest uname -a I get the same error.

1 Like