Undefined The oc image mirror command fails when mirroring images with uncompressed layers to registries like quay.io that don't accept them. While oc image mirror correctly mirrors images as-is, it should provide a fallback mechanism when the target registry rejects uncompressed layers.
The Kubernetes pause image (registry.k8s.io/pause:3.10) contains uncompressed layers that quay.io rejects, breaking automation. Currently, we must manually exclude these images and mirror them with skopeo instead:
# This fails: echo "registry.k8s.io/pause:3.10 quay.io/bertinatto/community-e2e-images:e2e-25-registry-k8s-io-pause-3-10-b3MYAwZ_MelO9baY" | oc image mirror -f - --filter-by-os=.*
# This works because apparently skopeo somehow handles the layer conversion: skopeo copy --all --format oci docker://registry.k8s.io/pause:3.10 docker://quay.io/dest/pause:3.10
Every Kubernetes version update with a new pause image requires manual intervention to mirror the image with skopeo, and creating/merging a PR to openshift/release to manually mirror the image in metal jobs, delaying development work. For context, the exception [0] we have in openshift/origin for the pause image requires us to manually mirror all versions of the pause image in metal jobs[1].
oc image mirror should detect when the target registry rejects uncompressed layers and automatically handle the conversion, similar to how skopeo does.