Service Topology implementation

* Implement Service Topology for ipvs and iptables proxier
* Add test files
* API validation

pkg/apis/core/validation/validation.go

@@ -4053,6 +4053,35 @@ func ValidateService(service *core.Service) field.ErrorList {
 		ports[key] = true
 	}
 
+	// Validate TopologyKeys
+	if len(service.Spec.TopologyKeys) > 0 {
+		topoPath := specPath.Child("topologyKeys")
+		// topologyKeys is mutually exclusive with 'externalTrafficPolicy=Local'
+		if service.Spec.ExternalTrafficPolicy == core.ServiceExternalTrafficPolicyTypeLocal {
+			allErrs = append(allErrs, field.Forbidden(topoPath, "may not be specified when `externalTrafficPolicy=Local`"))
+		}
+		if len(service.Spec.TopologyKeys) > core.MaxServiceTopologyKeys {
+			allErrs = append(allErrs, field.TooMany(topoPath, len(service.Spec.TopologyKeys), core.MaxServiceTopologyKeys))
+		}
+		topoKeys := sets.NewString()
+		for i, key := range service.Spec.TopologyKeys {
+			keyPath := topoPath.Index(i)
+			if topoKeys.Has(key) {
+				allErrs = append(allErrs, field.Duplicate(keyPath, key))
+			}
+			topoKeys.Insert(key)
+			// "Any" must be the last value specified
+			if key == v1.TopologyKeyAny && i != len(service.Spec.TopologyKeys)-1 {
+				allErrs = append(allErrs, field.Invalid(keyPath, key, `"*" must be the last value specified`))
+			}
+			if key != v1.TopologyKeyAny {
+				for _, msg := range validation.IsQualifiedName(key) {
+					allErrs = append(allErrs, field.Invalid(keyPath, service.Spec.TopologyKeys, msg))
+				}
+			}
+		}
+	}
+
 	// Validate SourceRange field and annotation
 	_, ok := service.Annotations[core.AnnotationLoadBalancerSourceRangesKey]
 	if len(service.Spec.LoadBalancerSourceRanges) > 0 || ok {
@@ -4143,6 +4172,10 @@ func validateServiceExternalTrafficFieldsValue(service *core.Service) field.Erro
 		allErrs = append(allErrs, field.Invalid(field.NewPath("spec").Child("externalTrafficPolicy"), service.Spec.ExternalTrafficPolicy,
 			fmt.Sprintf("ExternalTrafficPolicy must be empty, %v or %v", core.ServiceExternalTrafficPolicyTypeCluster, core.ServiceExternalTrafficPolicyTypeLocal)))
 	}
+	// 'externalTrafficPolicy=Local' is mutually exclusive with topologyKeys
+	if service.Spec.ExternalTrafficPolicy == core.ServiceExternalTrafficPolicyTypeLocal && len(service.Spec.TopologyKeys) > 0 {
+		allErrs = append(allErrs, field.Forbidden(field.NewPath("spec").Child("externalTrafficPolicy"), "externalTrafficPolicy must not be set to 'Local' when topologyKeys is specified"))
+	}
 	if service.Spec.HealthCheckNodePort < 0 {
 		allErrs = append(allErrs, field.Invalid(field.NewPath("spec").Child("healthCheckNodePort"), service.Spec.HealthCheckNodePort,
 			"HealthCheckNodePort must be not less than 0"))

pkg/apis/core/validation/validation_test.go

@@ -18,6 +18,7 @@ package validation
 
 import (
 	"bytes"
+	"fmt"
 	"math"
 	"reflect"
 	"strings"
@@ -9380,6 +9381,7 @@ func TestValidatePodEphemeralContainersUpdate(t *testing.T) {
 
 func TestValidateService(t *testing.T) {
 	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.SCTPSupport, true)()
+	defer featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ServiceTopology, true)()
 
 	testCases := []struct {
 		name     string
@@ -10058,6 +10060,66 @@ func TestValidateService(t *testing.T) {
 			},
 			numErrs: 1,
 		},
+		{
+			name: "valid topology keys",
+			tweakSvc: func(s *core.Service) {
+				s.Spec.TopologyKeys = []string{
+					"kubernetes.io/hostname",
+					"failure-domain.beta.kubernetes.io/zone",
+					"failure-domain.beta.kubernetes.io/region",
+					v1.TopologyKeyAny,
+				}
+			},
+			numErrs: 0,
+		},
+		{
+			name: "invalid topology key",
+			tweakSvc: func(s *core.Service) {
+				s.Spec.TopologyKeys = []string{"NoUppercaseOrSpecialCharsLike=Equals"}
+			},
+			numErrs: 1,
+		},
+		{
+			name: "too many topology keys",
+			tweakSvc: func(s *core.Service) {
+				for i := 0; i < core.MaxServiceTopologyKeys+1; i++ {
+					s.Spec.TopologyKeys = append(s.Spec.TopologyKeys, fmt.Sprintf("topologykey-%d", i))
+				}
+			},
+			numErrs: 1,
+		},
+		{
+			name: `"Any" was not the last key`,
+			tweakSvc: func(s *core.Service) {
+				s.Spec.TopologyKeys = []string{
+					"kubernetes.io/hostname",
+					v1.TopologyKeyAny,
+					"failure-domain.beta.kubernetes.io/zone",
+				}
+			},
+			numErrs: 1,
+		},
+		{
+			name: `duplicate topology key`,
+			tweakSvc: func(s *core.Service) {
+				s.Spec.TopologyKeys = []string{
+					"kubernetes.io/hostname",
+					"kubernetes.io/hostname",
+					"failure-domain.beta.kubernetes.io/zone",
+				}
+			},
+			numErrs: 1,
+		},
+		{
+			name: `use topology keys with externalTrafficPolicy=Local`,
+			tweakSvc: func(s *core.Service) {
+				s.Spec.ExternalTrafficPolicy = "Local"
+				s.Spec.TopologyKeys = []string{
+					"kubernetes.io/hostname",
+				}
+			},
+			numErrs: 2,
+		},
 	}
 
 	for _, tc := range testCases {