Change ipFamilyPolicy from RequiredDualStack to SingleStack for headless kubernetes services

[Liwanshi]

What is missing?

IPv4/IPv6 dual-stack networking graduates to GA. Since 1.21, Kubernetes clusters are enabled to support dual-stack networking by default. In 1.23, the IPv6DualStack feature gate is removed.

For Headless Service , If the service doesn't have any selectors defined then it is defaulted to RequireDualStack on any cluster (single- or dual-stack)

caas-cluster-dc-1-additional-seed-service is a headless service so need to explicitly set it to IPv4 and SingleStack

Why is this needed?

Since 1.21, Kubernetes clusters are enabled to support dual-stack networking by default. In 1.23, the IPv6DualStack feature gate is removed.

[Liwanshi]

What needs to be done

func newAdditionalSeedServiceForCassandraDatacenter(dc *api.CassandraDatacenter) *corev1.Service {
	labels := dc.GetDatacenterLabels()
	oplabels.AddOperatorLabels(labels, dc)
	var service corev1.Service
	service.ObjectMeta.Name = dc.GetAdditionalSeedsServiceName()
	service.ObjectMeta.Namespace = dc.Namespace
	service.ObjectMeta.Labels = labels
	// We omit the label selector because we will create the endpoints manually
	service.Spec.Type = "ClusterIP"
	service.Spec.ClusterIP = "None"
	service.Spec.PublishNotReadyAddresses = true
        // Adding ipFamilies and ipFamilyPolicy
	service.Spec.IPfamilies = []corev1.IPFamily{"IPv4"}
	service.Spec.IPFamilyPolicy = corev1.IPFamilyPolicySingleStack

	addAdditionalOptions(&service, &dc.Spec.AdditionalServiceConfig.AdditionalSeedService)


	utils.AddHashAnnotation(&service)

	return &service

[Liwanshi]

no need to implement, tested a new cluster creation on 1.23 k8s version without any changes