cri-o/vendor/github.com/opencontainers/image-spec/manifest-list.md

OCI Image Manifest List Specification

The manifest list is a higher-level manifest which points to specific image manifests for one or more platforms. While the use of a manifest list is OPTIONAL for image providers, image consumers SHOULD be prepared to process them.

This section defines the application/vnd.oci.image.manifest.list.v1+json media type. For the media type(s) that this document is compatible with, see the matrix.

Manifest List Property Descriptions

• schemaVersion int

  This REQUIRED property specifies the image manifest schema version. For this version of the specification, this MUST be 2 to ensure backward compatibility with older versions of Docker. The value of this field will not change. This field MAY be removed in a future version of the specification.

• mediaType string

  This property is reserved for use, to maintain compatibility. When used, this field contains the media type of this document, which differs from the descriptor use of mediaType.

• manifests array of objects

  This REQUIRED property contains a list of manifests for specific platforms. While the property MUST be present, the size of the array MAY be zero.

  Each object in manifests is a descriptor with the following additional properties and restrictions:

  • mediaType string

    This descriptor property has additional restrictions for manifests. Implementations MUST support at least the following media types:

    • application/vnd.oci.image.manifest.v1+json

    Manifest lists concerned with portability SHOULD use one of the above media types.

  • platform object

    This REQUIRED property describes the platform which the image in the manifest runs on.

    • architecture string

      This REQUIRED property specifies the CPU architecture. Manifest lists SHOULD use, and implementations SHOULD understand, values supported by runtime-spec's platform.arch.

    • os string

      This REQUIRED property specifies the operating system. Manifest lists SHOULD use, and implementations SHOULD understand, values supported by runtime-spec's platform.os.

    • os.version string

      This OPTIONAL property specifies the operating system version, for example 10.0.10586.

    • os.features array of strings

      This OPTIONAL property specifies an array of strings, each specifying a mandatory OS feature (for example on Windows win32k).

    • variant string

      This OPTIONAL property specifies the variant of the CPU, for example armv6l to specify a particular CPU variant of the ARM CPU.

    • features array of strings

      This OPTIONAL property specifies an array of strings, each specifying a mandatory CPU feature (for example sse4 or aes).

• annotations string-string map

  This OPTIONAL property contains arbitrary metadata for the manifest list. This OPTIONAL property MUST use the annotation rules.

  See Pre-Defined Annotation Keys.

Example Manifest List

Example showing a simple manifest list pointing to image manifests for two platforms:

{
  "schemaVersion": 2,
  "manifests": [
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "size": 7143,
      "digest": "sha256:e692418e4cbaf90ca69d05a66403747baa33ee08806650b51fab815ad7fc331f",
      "platform": {
        "architecture": "ppc64le",
        "os": "linux"
      }
    },
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "size": 7682,
      "digest": "sha256:5b0bcabd1ed22e9fb1310cf6c2dec7cdef19f0ad69efa1f392e94a4333501270",
      "platform": {
        "architecture": "amd64",
        "os": "linux",
        "os.features": [
          "sse4"
        ]
      }
    }
  ],
  "annotations": {
    "com.example.key1": "value1",
    "com.example.key2": "value2"
  }
}