get_hub_manifest.sh

#!/bin/sh

IMAGE="${1:-}"
TAG="${2:-}"

if [ -z "${IMAGE}" ]
then
  echo "Missing IMAGE"
  echo "Usage: ${0} namespace/repo tag"
  exit 1
fi

if [ -z "${TAG}" ]
then
  echo "Missing TAG"
  echo "Usage: ${0} namespace/repo tag"
  exit 1
fi

curl -s \
  -H "Accept: application/vnd.docker.distribution.manifest.list.v2+json" \
  -H "Authorization: Bearer $(curl -s "https://auth.docker.io/token?service=registry.docker.io&scope=repository:${IMAGE}:pull,push" | jq -r .token)" \
  "https://registry.hub.docker.com/v2/${IMAGE}/manifests/${TAG}" \
  | jq .

output+example

$ ./get_hub_manifest.sh library/nginx latest
{
  "manifests": [
    {
      "digest": "sha256:099019968725f0fc12c4b69b289a347ae74cc56da0f0ef56e8eb8e0134fc7911",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "amd64",
        "os": "linux"
      },
      "size": 948
    },
    {
      "digest": "sha256:e5e4a3e39e58dc4c40064c9433740e7c2031516375c201aab26649dcfa2c7a6d",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "arm",
        "os": "linux",
        "variant": "v7"
      },
      "size": 948
    },
    {
      "digest": "sha256:83712aa5ba1a5a9ad7d1d230560a0229e3a962c40754483f86c2e82c9239cd06",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "arm64",
        "os": "linux",
        "variant": "v8"
      },
      "size": 948
    },
    {
      "digest": "sha256:07a8c4f6df9dea75fb37fbc08348d6abb820328911e5536ce4ca8475e08d7a35",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "386",
        "os": "linux"
      },
      "size": 948
    },
    {
      "digest": "sha256:b79ba2582b8b3a81aba6e57ad068ebaeb675c44bf25737a3e767d99ca1cb414a",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "ppc64le",
        "os": "linux"
      },
      "size": 948
    },
    {
      "digest": "sha256:69e12814dcae07a6a1095b2d26d4bac5b2b09966d230cf6a0b972843116a8347",
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "platform": {
        "architecture": "s390x",
        "os": "linux"
      },
      "size": 948
    }
  ],
  "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
  "schemaVersion": 2
}