Containerd configuration needs to show new format version

[afbjorklund]

This is a Feature Request

Currently documentation only shows the old "v2" format:

https://kubernetes.io/docs/setup/production-environment/container-runtimes/#containerd

In containerd 1.x:

[plugins."io.containerd.grpc.v1.cri"]
  sandbox_image = "registry.k8s.io/pause:3.2"

What would you like to be added

It should show both the "v2" (1.x) and "v3" (2.x) formats:

https://github.com/containerd/containerd/blob/release/2.0/docs/cri/config.md

In containerd 2.x:

    [plugins.'io.containerd.cri.v1.images'.pinned_images]
      sandbox = 'registry.k8s.io/pause:3.10'

Why is this needed

The old format is still supported in containerd 2.0, but in future versions it is deprecated (similar to "v1" today)

For the transitioning period (i.e. before 1.x is EOL), the duplicated documentation needs to shown both versions.

https://containerd.io/releases/#kubernetes-support

Both versions are currently documented upstream.

Comments

There is a related bug with kubeadm preflight, that makes it fail to detect the configured version no matter what...

warning: detected that the sandbox image "" of the container runtime is inconsistent with that used by kubeadm

But the user can verify the current config with containerd config dump, even though it is missing from crictl info.

• Export compatibility config.sandboxImage in CRI containerd/containerd#11114

[vaibhav2107]

/language en

[kundan2707]

/triage accepted

[pegasas]

/assign @pegasas