promote grpcProbes to beta

[SergeyKanzhelev]

/kind feature
/sig node

KEP: kubernetes/enhancements#2727

What this PR does / why we need it:

KEP promotion to beta.

Which issue(s) this PR fixes:

KEP: kubernetes/enhancements#2727

Special notes for your reviewer:

The feature is tested wtth the e2e tests and can be tested in "real life" cluster on GKE:

gcloud config set project $PROJECT
gcloud config set compute/zone asia-east1-c

gcloud container clusters create test-grpc \
    --enable-kubernetes-alpha \
    --no-enable-autorepair \
    --no-enable-autoupgrade \
    --release-channel=rapid \
    --cluster-version=1.23

gcloud container clusters get-credentials test-grpc --zone asia-east1-c --project $PROJECT

Try something like this pod:

apiVersion: v1
kind: Pod
metadata:
  name: etcd-with-grpc
spec:
  containers:
  - name: etcd
    image: k8s.gcr.io/etcd:3.5.1-0
    command: [ "/usr/local/bin/etcd", "--data-dir",  "/var/lib/etcd", "--listen-client-urls", "http://0.0.0.0:2379", "--advertise-client-urls", "http://127.0.0.1:2379", "--log-level", "debug"]
    ports:
    - containerPort: 2379
    livenessProbe:
      grpc:
        port: 2379
      initialDelaySeconds: 10

More end to end tests will be added with the new agnhost command: #108500 This is not blocking

Does this PR introduce a user-facing change?

Support for gRPC probes is now in beta. GRPCContainerProbe feature gate is enabled by default.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

• KEP: Add gRPC probe to Pod.Spec.Container.{Liveness,Readiness,Startup}Probe enhancements#2727
• Docs PR: promote GRPCContainerProbe to beta website#31805

[rphillips]

/lgtm

[k8s-triage-robot]

This PR may require API review.

If so, when the changes are ready, complete the pre-review checklist and request an API review.

Status of requested reviews is tracked in the API Review project.

[bowei]

/lgtm

[SergeyKanzhelev]

/label api-review

[liggitt]

KEP included this bit in beta graduation:

Depending on skew strategy:

kubelet version skew ensures all (kubelet ver, cluster ver) support the feature.

only 1.23+ kubelets support the feature, so against a 1.24 server, what would a 1.22 kubelet do with a pod that specified a grpc probe?

[liggitt]

only 1.23+ kubelets support the feature, so against a 1.24 server, what would a 1.22 kubelet do with a pod that specified a grpc probe?

answering my own question, kubelets < 1.24 would return a missing probe handler for ... error by default:

kubernetes/pkg/kubelet/prober/prober.go

Lines 204 to 209 in ab69524

	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.GRPCContainerProbe) && p.GRPC != nil {
	host := &(status.PodIP)
	service := p.GRPC.Service
	klog.V(4).InfoS("GRPC-Probe", "host", host, "service", service, "port", p.GRPC.Port, "timeout", timeout)
	return pb.grpc.Probe(*host, *service, int(p.GRPC.Port), timeout)
	}

[liggitt]

API mechanics lgtm, but the e2e test and kubelet support bit from the KEP need answering before merge

[SergeyKanzhelev]

/test pull-kubernetes-node-e2e-containerd-features

[SergeyKanzhelev]

/retest

[ehashman]

No code changes, just updating API and feature gates.

/assign @derekwaynecarr
where did we land on TLS support for beta? kubernetes/enhancements#3177 (comment)

[SergeyKanzhelev]

where did we land on TLS support for beta? kubernetes/enhancements#3177 (comment)

I replied on the comment. We do support TLS, but do not check the certificate. Same as HTTP.

[wgahnagl]

/lgtm

[SergeyKanzhelev]

@liggitt can you please approve for API

[liggitt]

/approve
for API changes

node approval at #108522 (review)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: liggitt, mrunalp, SergeyKanzhelev

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Needs approval from an approver in each of these files:

• api/OWNERS [liggitt]
• pkg/apis/OWNERS [liggitt]
• pkg/features/OWNERS [liggitt]
• pkg/generated/openapi/OWNERS [liggitt]
• staging/src/k8s.io/api/OWNERS [liggitt]
• test/e2e/common/OWNERS [SergeyKanzhelev,liggitt]

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[ehashman]

/milestone v1.24