Consider having kubeadm version annotations for Pod objects

[neolit123]

as per the discussion here:
kubernetes/kubernetes#70893 (review)

the alternative to Pod metadata is to have comments in manifest files, but these have to be parsed.

cc @fabriziopandini @luxas @rosti
/kind design
/priority important-longterm

[neolit123]

/assign @timothysc @luxas @fabriziopandini
WDYT
(proposed by @fabriziopandini here)

[fabriziopandini]

+1
I think that making explicit that an object was created by kubeadm, tracking the last kubeadm version touched the object and when is a good practice.
It add transparency to what kubeadm does and open ups to add more robust version specific logic

[NicolasT]

At first I was concerned this would imply the pods to be restarted because the manifest would always change. However, that's fine because when upgrading kubeadm-based deployments you'll always have at least some updates to field in the pod, like image version (maybe except for etcd if the preferred version and configuration doesn't change across kubeadm/K8s versions, which you may not want to restart without good cause?).

So, big 👍 (modulo etcd)

[neolit123]

seems a bit too late to change in this cycle, but IMHO a nice to have.
possibly early 1.15 we can get back to this.

[timothysc]

I debate if this has benefit in the future.

[astrieanna]

/remove-help

because it sounds as if there's some disagreement on whether this should be implemented.

[fabriziopandini]

/close
While i'm still convinced it is nice to have, currently there is no concrete use case for having those annotation. The ticket can always be re-opened/re-created if necessary

[k8s-ci-robot]

@fabriziopandini: Closing this issue.

In response to this:

/close
While i'm still convinced it is nice to have, currently there is no concrete use case for having those annotation. The ticket can always be re-opened/re-created if necessary

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[neolit123]

SGTM. its a "nice-to-have safeguard" - viable if we reach another case where we have to mutate the manifests by knowning which version they were created with. hopefully not.