Cilium nodeport

[olemarkus]

Cilium is capable of fully replacing kube-proxy by running in NodePort mode.
This PR will prevent kops from installing kube-proxy if NodePort is enabled on the Cilium addon.

This is implemented similar to how kube-proxy is disabled by kube-router. I do wonder if forcing kubeProxy.enabled=false would be a bit cleaner than just disabling it implicitly by the cilium.enableNodePort setting.

Note: This feature requires kernel version 4.19.57 or later

[k8s-ci-robot]

Hi @olemarkus. Thanks for your PR.

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[rifelpet]

/ok-to-test

[olemarkus]

/retest

[johngmyers]

/test pull-kops-e2e-kubernetes-aws

[olemarkus]

/test pull-kops-e2e-kubernetes-aws

[johngmyers]

Should use field.Forbidden() instead.
Should use fieldspec.Child("KubeProxy").Child("Enabled") to refer to the correct field.

[rifelpet]

Just to help me understand, would specifying Cilium.EnableNodePort=true and KubeProxy.Enabled=true result in a functional cluster? If so, then no longer allowing that combination of fields would be a breaking change. You mention this being similar to KubeRouter and I'm wondering if we should update the logic here to exclude kubeproxy nodeup tasks when Cilium.EnableNodePort=true:

kops/upup/pkg/fi/nodeup/command.go

Lines 252 to 254 in cbee4dc

	if c.cluster.Spec.Networking.Kuberouter == nil {
	loader.Builders = append(loader.Builders, &model.KubeProxyBuilder{NodeupModelContext: modelContext})
	} else {

[olemarkus]

Without this PR, enableNodePort doesn't work at all even though it was possible to set that flag.

My first idea was actually to drop the kubeProxy task like kuberouter does, but I think it is better to make the user do the right thing instead of just disabling it explicitly. The first thing that happens in the kubeProxy task is to check the kubeProxy.enabled flag and return if it is false.

[rifelpet]

I agree forcing the user to explicitly set kubeProxy.enabled=false is more clear. Maybe its worth mentioning both enableNodePort and its kubeProxy.enabled requirement in the docs? https://github.com/kubernetes/kops/blob/master/docs/networking.md#cilium-example-for-cni-and-network-policy

[olemarkus]

I want to create documentation both for this feature and for #8316. Just need to see how these play out first in case I need to do more changes.

[rifelpet]

ok great, thank you!

/lgtm
/approve

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[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: olemarkus, rifelpet

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[mazzy89]

asta la vista kube-proxy whoa