Support Kubelet Config

[Bo0km4n]

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

In currently, when user add additional config of kubelet, user add params to KubeadmConfigSpec resource .spec.joinConfiguration.nodeRegistration.kubeletExtraArgs.

But, recently kubelet warns some args will be removed and recommended that should be set via config file specified by kubelet's --config flag.
So when we use new version Kubernetes, this how to specify kubelet args maybe will be cannot use I think.

Therefore, I suggest to make setting KubeletConfig (https://pkg.go.dev/k8s.io/kubelet/config/v1beta1#KubeletConfiguration) via KubeadmConfig resource.

Detailed Description

NONE

Anything else you would like to add?

No response

Label(s) to be applied

/kind feature
One or more /area label. See https://github.com/kubernetes-sigs/cluster-api/labels?q=area for the list of labels.

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[killianmuldoon]

The KubeadmConfig used in CAPI is a mostly a mirror of the upstream type - https://kubernetes.io/docs/reference/config-api/kubeadm-config.v1beta3/. I'm not sure if the CAPI type is currently missing anything included in the upstream type. But I don't think including the full kubelet config is a real option here as it would be confusing to users.

One option for setting the KubeadmConfig would be to directly pass a file into the KubeadmConfig

This is a very interesting discussion though - I think it's linked to #8425

[neolit123]

ideally, CAPI should let kubeadm manage the kubeletconfiguration v1beta1 GVK.

I think it's linked to #8425

+1 to close in favor of 8425, where documenting existing approaches was proposed.

[Bo0km4n]

@killianmuldoon @neolit123
Thanks for your mentions.
Kubelet config contents are common and fixed, so I will try to set parameters of that via KubeadmConfigSpec .files.

[musaprg]

I prepared several examples for #8425. This would help for this purpose.

https://github.com/musaprg/cluster-api-kubelet-config-examples/blob/a46c8c80aa9b194cfda22747b14eaf4a0b86cca7/clusters/cloudinit/kubeadmcontrolplanetemplate.yaml#L10

[fabriziopandini]

I have copied the last comment to #8425 (thanks @musaprg for the example), so we can continue the discussion there.
/close

[k8s-ci-robot]

@fabriziopandini: Closing this issue.

In response to this:

I have copied the last comment to #8425 (thanks @musaprg for the example), so we can continue the discussion there.
/close

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