OCI: Add support for zstd:chunked compression format

[idleroamer]

What is the problem you're trying to solve Using containers on embedded devices, we strive to optimize the network bandwidth as well as on-board resource utilization like disk and memory. There is a new compression format (under discussion to be added to OCI spec https://github.com/opencontainers/image-spec/issues/803) namely zstd application/vnd.oci.image.layer.v1.tar+zstd which beside providing better compression enables file level de-duplication by partial tarball pulling which would be a huge resource optimization.

A good intro to partial image pulling https://www.redhat.com/sysadmin/faster-container-image-pulls

Describe the solution you'd like Both docker.io and quay.io registries support the new format already, see also followings for relevant efforts https://issues.redhat.com/browse/PROJQUAY-1417 https://github.com/quay/quay/pull/801

We'd like to see ACR supporting this compression format as well. Please bear in mind according to podman developers: For such feature to work, it is important that there is no recompression happening on the registry (i.e. the original compressed blob must be retrievable unchanged) since some metadata is embedded as part of the compression format itself.

[idleroamer]

There are two issues with support of zstd:chuncked specifically with podman client.

• podman creates a multi-range http request which depending on different factors could be a big range resulting in a header request > 8k which is not allowed by ACR.
• the next issue is that ACR does not support multi-range http request at all and returns the whole blob by such requests.

[github-actions[bot]]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days.

[dhirschfeld]

Ugh, a stale-bot.

[!IMPORTANT]

• https://blog.benwinding.com/github-stale-bots/
• https://github.com/Azure/AKS/issues/3474
• https://github.com/kubernetes/kubernetes/issues/103151

[dhirschfeld]

This is a feature request, wanted by the community.

Just because no maintainer has the time or inclination to work on it right now doesn't mean it's not a desired/beneficial feature to have, so this issue should remain open unless the resolution is that zstd:chunked support won't ever be added to the ACR.

[github-actions[bot]]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days.