Push zstd::chunked compressed container images to another tag
travier opened this issue · 2 comments
Using a better compression algorithm will mean smaller container images in the registry and faster pulls.
As the spec does not support multiple compression algorithms for a single tag, we should push those images to another tag.
See:
- https://www.redhat.com/sysadmin/faster-container-image-pulls
- containers/podman#15126
- containers/podman#15113
--compression-format=for podman: https://docs.podman.io/en/latest/markdown/podman-push.1.html--dest-compressoption for skopeo: https://github.com/containers/skopeo/blob/main/docs/skopeo-copy.1.md- containers/storage#775
- containers/image#1084
- moby/moby#28394 (comment)
- opencontainers/image-spec#803 (comment)
According to https://fedoraproject.org/wiki/Changes/zstd:chunked, container engine mostly support this format now.
But that would require some testing to not break older systems. So the push 2 times route is probably the safest in the short term. It should be reasonably easy to do.
Apparently it's possible to push both formats using a manifest list: https://discussion.fedoraproject.org/t/switch-fedora-container-images-to-support-zstd-chunked-format-by-default/123712/8
I will give this a try.