What is the problem you're trying to solve
KEP-4639 introduced support for subPath in OCI image volume mounts when the feature graduated to beta by extending CRI with an image_sub_path field for Mounts.
Describe the solution you'd like
Implement subPath for OCI image volume mounts. The current behavior I observe when defining a subPath is that it seems to be silently ignored and the root of the image is mounted.
Additional context
% ctr --version
ctr github.com/containerd/containerd/v2 v2.1.0-beta.0-18-g8237c496
% runc --version
runc version 1.2.5
commit: v1.2.5-0-g59923ef
spec: 1.2.0
go: go1.24.1
libseccomp: 2.5.4
% crictl version # built from master at https://github.com/kubernetes-sigs/cri-tools/commit/8869f48d4b120b5f775413b2ca7f8073586d08b4
Version: 0.1.0
RuntimeName: containerd
RuntimeVersion: v2.1.0-beta.0-18-g8237c496
RuntimeApiVersion: v1
% kubectl get nodes
kind-control-plane Ready control-plane 13m v1.33.0-beta.0.616+71eb04295ad273
What is the problem you're trying to solve
KEP-4639 introduced support for
subPathin OCI image volume mounts when the feature graduated to beta by extending CRI with animage_sub_pathfield forMounts.Describe the solution you'd like
Implement
subPathfor OCI image volume mounts. The current behavior I observe when defining asubPathis that it seems to be silently ignored and the root of the image is mounted.Additional context