Consider if to add more on KCP checks on machine status

[fabriziopandini]

What would you like to be added (User Story)?

As an operator, I need as much as possible info about the status of my control plane machines

Detailed Description

KCP implements checks for components status on controlled machines: API Server, Scheduler, Controller Manager, etcd

We should consider if to add more to the list of components, e.g. kube-proxy, kubelet (node).
This could provide an interesting signal to catch problems that could happen during upgrades when e.g. the control plane comes up because it is implemented via static pod, but other "regular" pods scheduled on the control plane node might not come up.

Anything else you would like to add?

No response

Label(s) to be applied

/kind feature
/area provider/control-plane-kubeadm

[sbueringer]

/triage accepted

I think this is important. When we discovered this issue: #10947 KCP was updating through the entire control plane and during the control plane upgrade only static pods came up (i.e. kube-proxy and CNI didn't). I.e. not even the Nodes became ready.

I think this is pretty dangerous behavior, worst case it makes the entire control plane unavailable. So it would be great to have some more checks to safeguard against this.

[sbueringer]

/help

This requires a little bit of research to figure out what kind of checks can be done (and we have to be careful that we don't break existing working upgrade flows).

[k8s-ci-robot]

@sbueringer:
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In response to this:

/help

This requires a little bit of research to figure out what kind of checks can be done (and we have to be careful that we don't break existing working upgrade flows).

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