feat: add VerticalPodAutoscaler to csi controller pod

[umagnus]

What type of PR is this?

/kind feature

What this PR does / why we need it:

feat: add VerticalPodAutoscaler to csi controller pod

Which issue(s) this PR fixes:

Fixes #

Requirements:

• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Special notes for your reviewer:

Release note:

none

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[umagnus]

AKS need to add a label for vpa admission controller webhook to impact csi controller pod in kube-system namespace, referenced to Can admission controller webhooks impact kube-system and internal AKS namespaces, wait for pr:kubernetes/autoscaler#7402 to completed

[voelzmo]

Hey, I came here via the reference in the VPA PR.
I see that you're about to use VPA for all the containers in the CSI controller Pod. My understanding is that the resource usage in those containers is usually pretty low – but I don't know the details of the Azure CSI controller.

I'm not sure if you tried this for a longer period of time already in some beta env or have long-term experience with other components with many containers in a single pod, but keep in mind that this change will lead to many additional interruptions for the Pod, as VPA will evict it when the recommendation for a container changes by more than 10% (which happens quickly for these small absolute values). This also happens if e.g. your initial requests are too high and the containers will be scaled down step by step. I'm not sure if those disruptions could become an issue – but if resource usage isn't expected to change much, it may just be better to not have VPA enabled for this and have fewer disruptions.

[andyzhangx]

@voelzmo thanks for the tips. we would like to use VPA mainly for CSI driver controller sidecar containers, the memory usage of those containers would grow dramatically when PV num grows in the cluster, current memory limit 500Mi is far from enough when there are a few thousand PVs in the cluster, in that case, the CSI driver would be OOM, that's the reason we want to use VPA.