dual stack services (#91824)

* api: structure change

* api: defaulting, conversion, and validation

* [FIX] validation: auto remove second ip/family when service changes to SingleStack

* [FIX] api: defaulting, conversion, and validation

* api-server: clusterIPs alloc, printers, storage and strategy

* [FIX] clusterIPs default on read

* alloc: auto remove second ip/family when service changes to SingleStack

* api-server: repair loop handling for clusterIPs

* api-server: force kubernetes default service into single stack

* api-server: tie dualstack feature flag with endpoint feature flag

* controller-manager: feature flag, endpoint, and endpointSlice controllers handling multi family service

* [FIX] controller-manager: feature flag, endpoint, and endpointSlicecontrollers handling multi family service

* kube-proxy: feature-flag, utils, proxier, and meta proxier

* [FIX] kubeproxy: call both proxier at the same time

* kubenet: remove forced pod IP sorting

* kubectl: modify describe to include ClusterIPs, IPFamilies, and IPFamilyPolicy

* e2e: fix tests that depends on IPFamily field AND add dual stack tests

* e2e: fix expected error message for ClusterIP immutability

* add integration tests for dualstack

the third phase of dual stack is a very complex change in the API,
basically it introduces Dual Stack services. Main changes are:

- It pluralizes the Service IPFamily field to IPFamilies,
and removes the singular field.
- It introduces a new field IPFamilyPolicyType that can take
3 values to express the "dual-stack(mad)ness" of the cluster:
SingleStack, PreferDualStack and RequireDualStack
- It pluralizes ClusterIP to ClusterIPs.

The goal is to add coverage to the services API operations,
taking into account the 6 different modes a cluster can have:

- single stack: IP4 or IPv6 (as of today)
- dual stack: IPv4 only, IPv6 only, IPv4 - IPv6, IPv6 - IPv4

* [FIX] add integration tests for dualstack

* generated data

* generated files

Co-authored-by: Antonio Ojea <aojea@redhat.com>

pkg/proxy/util/utils.go

@@ -256,13 +256,13 @@ func LogAndEmitIncorrectIPVersionEvent(recorder record.EventRecorder, fieldName,
 }
 
 // FilterIncorrectIPVersion filters out the incorrect IP version case from a slice of IP strings.
-func FilterIncorrectIPVersion(ipStrings []string, isIPv6Mode bool) ([]string, []string) {
-	return filterWithCondition(ipStrings, isIPv6Mode, utilnet.IsIPv6String)
+func FilterIncorrectIPVersion(ipStrings []string, ipfamily v1.IPFamily) ([]string, []string) {
+	return filterWithCondition(ipStrings, (ipfamily == v1.IPv6Protocol), utilnet.IsIPv6String)
 }
 
 // FilterIncorrectCIDRVersion filters out the incorrect IP version case from a slice of CIDR strings.
-func FilterIncorrectCIDRVersion(ipStrings []string, isIPv6Mode bool) ([]string, []string) {
-	return filterWithCondition(ipStrings, isIPv6Mode, utilnet.IsIPv6CIDRString)
+func FilterIncorrectCIDRVersion(ipStrings []string, ipfamily v1.IPFamily) ([]string, []string) {
+	return filterWithCondition(ipStrings, (ipfamily == v1.IPv6Protocol), utilnet.IsIPv6CIDRString)
 }
 
 func filterWithCondition(strs []string, expectedCondition bool, conditionFunc func(string) bool) ([]string, []string) {
@@ -376,3 +376,30 @@ func NewFilteredDialContext(wrapped DialContext, resolv Resolver, opts *Filtered
 		return wrapped(ctx, network, address)
 	}
 }
+
+// GetClusterIPByFamily returns a service clusterip by family
+func GetClusterIPByFamily(ipFamily v1.IPFamily, service *v1.Service) string {
+	// allowing skew
+	if len(service.Spec.IPFamilies) == 0 {
+		if len(service.Spec.ClusterIP) == 0 || service.Spec.ClusterIP == v1.ClusterIPNone {
+			return ""
+		}
+
+		IsIPv6Family := (ipFamily == v1.IPv6Protocol)
+		if IsIPv6Family == utilnet.IsIPv6String(service.Spec.ClusterIP) {
+			return service.Spec.ClusterIP
+		}
+
+		return ""
+	}
+
+	for idx, family := range service.Spec.IPFamilies {
+		if family == ipFamily {
+			if idx < len(service.Spec.ClusterIPs) {
+				return service.Spec.ClusterIPs[idx]
+			}
+		}
+	}
+
+	return ""
+}