Manifest Annotations

Annotations, which are supported by OCI Image Manifest and OCI Content Descriptors, are also supported by oras.

Make annotations

Users can make annotations to the manifest, the config, and individual files (i.e. layers) by the --annotation-file file option. The annotations file is a JSON file with the following format:

{
  "<filename>": {
    "<annotation_key>": "annotation_value"
  }
}

There are two special filenames / entries:

• $config is reserved for the annotation of the manifest config.
• $manifest is reserved for the annotation of the manifest itself.

For instance, the following annotation file annotations.json:

{
  "$config": {
    "hello": "world"
  },
  "$manifest": {
    "foo": "bar"
  },
  "cake.txt": {
    "fun": "more cream"
  }
}

Running the following command

oras push --annotation-file annotations.json localhost:5000/club:party cake.txt juice.txt

results in

{
  "schemaVersion": 2,
  "config": {
    "mediaType": "application/vnd.oci.image.config.v1+json",
    "digest": "sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a",
    "size": 2,
    "annotations": {
      "hello": "world"
    }
  },
  "layers": [
    {
      "mediaType": "application/vnd.oci.image.layer.v1.tar",
      "digest": "sha256:22af0898315a239117308d39acd80636326c4987510b0ec6848e58eb584ba82e",
      "size": 6,
      "annotations": {
        "fun": "more cream",
        "org.opencontainers.image.title": "cake.txt"
      }
    },
    {
      "mediaType": "application/vnd.oci.image.layer.v1.tar",
      "digest": "sha256:be6fe11876282442bead98e8b24aca07f8972a763cd366c56b4b5f7bcdd23eac",
      "size": 7,
      "annotations": {
        "org.opencontainers.image.title": "juice.txt"
      }
    }
  ],
  "annotations": {
    "foo": "bar"
  }
}