KEP-3935: newest control planes support oldest nodes

[liggitt]

• One-line PR description: initial draft of KEP-3935: Support Oldest Node With Newest Control Plane

• Issue link: Support Oldest Node With Newest Control Plane #3935

• Preview at https://github.com/liggitt/enhancements/tree/kep-3935/keps/sig-architecture/3935-oldest-node-newest-control-plane#summary with images rendered

Approvers:

• @dims # sig-architecture (skew policy) - KEP-3935: newest control planes support oldest nodes #3936 (comment)
• @neolit123 # sig-cluster-lifecycle (kubeadm use for skew job) - KEP-3935: newest control planes support oldest nodes #3936 (comment)
• @danwinship # sig-network (kube-proxy) - KEP-3935: newest control planes support oldest nodes #3936 (comment)
• @dchen1107 # sig-node (kubelet) - KEP-3935: newest control planes support oldest nodes #3936 (comment)
• @deads2k (PRR) - KEP-3935: newest control planes support oldest nodes #3936 (comment)

[shaneutt]

/cc

[ahg-g]

/lgtm

from sig-scheduling

[neolit123]

sig-cluster-lifecycle (kubeadm use for skew job)

/approve

[nckturner]

From a cloud provider perspective, the CCM needs to be compatible with node annotations like alpha.kubernetes.io/provided-node-ip (e.g. kubernetes/kubernetes#109794, kubernetes/kubernetes#112184).

Overall this seems like a good idea.
/lgtm from sig-cloud-provider
FYI @andrewsykim @cheftako @elmiko @bridgetkromhout

[deads2k]

Thanks for the list of all features. looks like 1.28 got lucky :)

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dchen1107, deads2k, dims, liggitt, neolit123, vincepri

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• keps/prod-readiness/OWNERS [deads2k]
• keps/sig-architecture/OWNERS [dims]

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[liggitt]

From a cloud provider perspective, the CCM needs to be compatible with node annotations like alpha.kubernetes.io/provided-node-ip (e.g. kubernetes/kubernetes#109794, kubernetes/kubernetes#112184).

That's a good call-out, I added that KEP as needing an update with an explicit timeline for the "The cloud provider will only look at the new annotation." item that accommodates n-3 nodes

[marosset]

LGTM for sig-windows

[marosset]

/lgtm

[liggitt]

Thanks for all the reviews and feedback. I think the open questions are resolved and work for this KEP and related work is captured in the document. I'll leave this for a day or so in case anyone has follow-up questions/comments, and plan to drop the hold Friday.

[dims]

drop the hold Friday

+100

[vinaykul]

/lgtm

[jsafrane]

lgtm from storage POV.

[liggitt]

/hold cancel