gistfile1.txt

# Putting annotations on the layer descriptor in the manifest.
# Pros:
# 1. Very intuitive, easy to parse/understand (by eye and in code).
# Cons:
# 1. If the target registry doesn't support OCI format annotations
#    (probably most registries), this breaks.
# 2. If we are just copying a whole image over, this changes the manifest
#    digest (not an issue, probably).
{
   "schemaVersion": 2,
   "config": {
      "mediaType": "application/vnd.oci.image.config.v1+json",
      "size": 1497,
      "digest": "sha256:e1ddd7948a1c31709a23cc5b7dfe96e55fc364f90e1cebcde0773a1b5a30dcda"
   },
   "layers": [
      {
         "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
         "size": 733241,
         "digest": "sha256:8c5a7da1afbc602695fcb2cd6445743cec5ff32053ea589ea9bd8773b7068185",
         "annotations": {
           "dev.knative.build.image.registry.mount": "index.docker.io/library/busybox"
         }
      }
   ]
}

# Putting annotations on the manifest descriptor in index.json.
# Pros:
# 1. Compatible with docker format images (thus all registries except quay).
# 2. Doesn't affect manifest digest, since annotation is external to manifest.
# Cons:
# 1. Need to define some grammar for specifying mapping from layers to source
#    repositories (could sidestep that by just serializing JSON?).
# 2. Probably gets unwieldy with a lot of layers.
{
  "schemaVersion": 2,
  "manifests": [
    {
      "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
      "size": 527,
      "digest": "sha256:5e8e0509e829bb8f990249135a36e81a3ecbe94294e7a185cc14616e5fad96bd",
      "annotations": {
        "org.opencontainers.image.ref.name": "busybox",
        "dev.knative.build.image.registry.mount": "sha256:8c5a7da1afbc602695fcb2cd6445743cec5ff32053ea589ea9bd8773b7068185=index.docker.io/library/busybox"
      }
    }
}