Consider using the `org.opencontainers.image.title` to define filename for binary layer files

[amisevsk]

Description

The current spec uses model-spec-specific annotations to define file metadata such as file name and path.

Podman recently added support for mounting generic OCI artifacts as volumes, where the filename for the layer is defined via the org.opencontainers.image.title annotation on layer, e.g.

{
  "schemaVersion": 2,
  "mediaType": "application/vnd.oci.image.manifest.v1+json",
  "artifactType": "application/vnd.cnai.model.manifest.v1+json",
  "config": {
    "mediaType": "application/vnd.oci.empty.v1+json",
    "digest": "sha256:44136fa355b3678a1146ad16f7e8649e94fb4fc21fe77e8310c060f61caaff8a",
    "size": 2,
    "data": "e30="
  },
  "layers": [
    {
      "mediaType": "application/vnd.cnai.model.weight.v1.raw",
      "digest": "sha256:97c8eb053060713dc121b36c0d6e1e72c1d8dd8455e5e0e0a67026610533b2f9",
      "size": 27,
      "annotations": {
        "org.opencontainers.image.title": "test.txt"
      }
    }
  ]
}

Executing

# This is the manifest above
podman run -it --rm \
    --mount type=artifact,src=quay.io/amisevsk0/oci-artifacts:podman-raw-data-empty-config,dst=/data \
    fedora:latest \
    /bin/bash

will mount a file to /data/test.txt in the fedora:latest container.

Note that in podman's case, the blob referred to by the layer's descriptor is mounted as-is, directly from artifact storage (i.e. read-only); the mediaType is currently ignored as far as I can tell and there is no extraction of tarballs, etc.

Should we instead adopt the behaviour podman has defined for OCI artifact mounts for better interoperability?

[aftersnow]

In the OCI image spec, the annotation org.opencontainers.image.title is defined as Human-readable title of the image (string), it can be any thing, I am not sure if it is a good idea to used for file path or file name. Maybe it will be a problem?

[amisevsk]

It's not strictly in adherence with the OCI specification (where the annotation is intended to be manifest-level), but Podman is currently (re)using the same annotation -- except defined on manifest layers -- to determine a filename.

We can also leave it out of the spec, and tools can always add it separately. I don't feel to strongly in either direction.

[amisevsk]

The modelpack annotation may also be more useful, as I don't believe the podman implementation covers creating subdirectories.

[github-actions]

This issue is stale because it has been open 40 days with no activity.

[github-actions]

This issue was closed because it has been stalled for 7 days with no activity.