Stevedore.Descriptor (Stevedore v0.2.0)

A typed, digest-addressed pointer to content (the OCI descriptor).

Descriptors are how a manifest references its config and layers, and how an index references its per-platform manifests: each carries a media_type, the digest and size of the target bytes, and optional metadata (platform, annotations, urls, artifact_type).

Spec: OCI image-spec, descriptor.

Summary

Types

platform()

t()

Functions

from_json(other)

Builds a descriptor from a decoded JSON object (string keys, as on the wire).

from_json_full(json)

Builds a descriptor from JSON, attaching the optional fields (platform, annotations, urls, artifactType) present in json.

to_json(d)

Renders a descriptor back to a JSON-ready map (string keys), omitting empty optional fields.

Types

platform()

@type platform() :: %{
  os: String.t(),
  architecture: String.t(),
  variant: String.t() | nil,
  os_version: String.t() | nil
}

t()

@type t() :: %Stevedore.Descriptor{
  annotations: %{optional(String.t()) => String.t()} | nil,
  artifact_type: String.t() | nil,
  digest: Stevedore.Digest.t(),
  media_type: String.t(),
  platform: platform() | nil,
  size: non_neg_integer(),
  urls: [String.t()] | nil
}

Functions

from_json(other)

@spec from_json(map()) :: {:ok, t()} | {:error, {:bad_input, term()}}

Builds a descriptor from a decoded JSON object (string keys, as on the wire).

Examples

iex> {:ok, d} = Stevedore.Descriptor.from_json(%{
...>   "mediaType" => "application/vnd.oci.image.layer.v1.tar+gzip",
...>   "digest" => "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
...>   "size" => 32
...> })
iex> {d.size, d.digest.algorithm}
{32, :sha256}

from_json_full(json)

@spec from_json_full(map()) :: {:ok, t()} | {:error, {:bad_input, term()}}

Builds a descriptor from JSON, attaching the optional fields (platform, annotations, urls, artifactType) present in json.

to_json(d)

@spec to_json(t()) :: map()

Renders a descriptor back to a JSON-ready map (string keys), omitting empty optional fields.

Examples

iex> d = %Stevedore.Descriptor{media_type: "application/vnd.oci.image.config.v1+json",
...>   digest: Stevedore.Digest.compute(""), size: 0}
iex> Stevedore.Descriptor.to_json(d)["mediaType"]
"application/vnd.oci.image.config.v1+json"