Follow up from #11060, tracked in #12329

what is our stated support or testing for transitive or third-party dependencies?

I see three main categories of dependencies and sets of questions that are unanswered in current documentation:

• etcd
  • what versions are tested? what is the minimum and maximum supported version? should this info be in a machine-consumable format?
  • is there a tested or recommended upgrade order/process?
• dependencies (things the kubelet/apiserver/controllers interact with via CRI, CNI, CSI, KMS APIs)
  • what API versions are tested/supported
  • what specific implementations/versions are tested?
  • is there a tested or recommended upgrade order/process?
  • when we say we recommend container engine or CSI driver A at version B for k8s release 1.n, does that imply we expect k8s release 1.n+2 to support the same to cover maximum skew?
• addons that are bundled with kubernetes releases
  • what versions of these dependencies are tested and bundled in kubernetes release 1.X? should this info be in a machine-consumable format?
  • if there a tested or recommended upgrade order/process (e.g. if the add-on is defined in a daemonset, should the new daemonset be applied before/after upgrading the control plane, before/after upgrading the kubelets)?

Finally, where should this information be maintained (a unified page with a version matrix, per-release, or something else)?

@kubernetes/sig-testing @kubernetes/sig-release @kubernetes/sig-cluster-lifecycle

(#12233 is open specifically for etcd)

Page to Update:
https://kubernetes.io/docs/setup/version-skew-policy/