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>

test/integration/dualstack/main_test.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package dualstack
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+func TestMain(m *testing.M) {
+	framework.EtcdMain(m.Run)
+}