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/controller/util/endpoint/controller_utils.go

@@ -32,10 +32,8 @@ import (
 	v1listers "k8s.io/client-go/listers/core/v1"
 	"k8s.io/client-go/tools/cache"
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
-	"k8s.io/kubernetes/pkg/apis/core/v1/helper"
 	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/util/hash"
-	utilnet "k8s.io/utils/net"
 )
 
 // ServiceSelectorCache is a cache of service selectors to avoid high CPU consumption caused by frequent calls to AsSelectorPreValidated (see #73527)
@@ -277,18 +275,3 @@ func (sl portsInOrder) Less(i, j int) bool {
 	h2 := DeepHashObjectToString(sl[j])
 	return h1 < h2
 }
-
-// IsIPv6Service checks if svc should have IPv6 endpoints
-func IsIPv6Service(svc *v1.Service) bool {
-	if helper.IsServiceIPSet(svc) {
-		return utilnet.IsIPv6String(svc.Spec.ClusterIP)
-	} else if svc.Spec.IPFamily != nil {
-		return *svc.Spec.IPFamily == v1.IPv6Protocol
-	} else {
-		// FIXME: for legacy headless Services with no IPFamily, the current
-		// thinking is that we should use the cluster default. Unfortunately
-		// the endpoint controller doesn't know the cluster default. For now,
-		// assume it's IPv4.
-		return false
-	}
-}