Refactor addBackendPolicyIfConfigured to allow future features

pkg/i2gw/providers/gce/extensions/input_extensions.go

@@ -0,0 +1,48 @@
+/*
+Copyright 2024 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 extensions
+
+import (
+	"fmt"
+
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/intermediate"
+	backendconfigv1 "k8s.io/ingress-gce/pkg/apis/backendconfig/v1"
+)
+
+func ValidateBeConfig(beConfig *backendconfigv1.BackendConfig) error {
+	if beConfig.Spec.SessionAffinity != nil {
+		if err := validateSessionAffinity(beConfig); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func validateSessionAffinity(beConfig *backendconfigv1.BackendConfig) error {
+	if beConfig.Spec.SessionAffinity.AffinityCookieTtlSec != nil && beConfig.Spec.SessionAffinity.AffinityType != "GENERATED_COOKIE" {
+		return fmt.Errorf("BackendConfig has affinityCookieTtlSec set, but affinityType is not GENERATED_COOKIE")
+	}
+	return nil
+}
+
+func BuildIRSessionAffinityConfig(beConfig *backendconfigv1.BackendConfig) *intermediate.SessionAffinityConfig {
+	return &intermediate.SessionAffinityConfig{
+		AffinityType: beConfig.Spec.SessionAffinity.AffinityType,
+		CookieTTLSec: beConfig.Spec.SessionAffinity.AffinityCookieTtlSec,
+	}
+}

pkg/i2gw/providers/gce/extensions/output_extensions.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2024 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 extensions
+
+import (
+	gkegatewayv1 "github.com/GoogleCloudPlatform/gke-gateway-api/apis/networking/v1"
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/intermediate"
+)
+
+func BuildBackendPolicySessionAffinityConfig(serviceIR intermediate.ProviderSpecificServiceIR) *gkegatewayv1.SessionAffinityConfig {
+	affinityType := serviceIR.Gce.SessionAffinity.AffinityType
+	saConfig := gkegatewayv1.SessionAffinityConfig{
+		Type: &affinityType,
+	}
+	if affinityType == "GENERATED_COOKIE" {
+		saConfig.CookieTTLSec = serviceIR.Gce.SessionAffinity.CookieTTLSec
+	}
+	return &saConfig
+}

pkg/i2gw/providers/gce/gce_extensions.go

@@ -24,6 +24,7 @@ import (
 	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
 	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/intermediate"
 	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/notifications"
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/gce/extensions"
 	apiv1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
@@ -44,6 +45,10 @@ func buildGceServiceIR(ctx context.Context, storage *storage, ir *intermediate.I
 		if beConfig == nil {
 			continue
 		}
+		if err := extensions.ValidateBeConfig(beConfig); err != nil {
+			notify(notifications.ErrorNotification, err.Error(), beConfig)
+			continue
+		}
 		gceServiceIR := beConfigToGceServiceIR(beConfig)
 		services := beConfigToSvcs[beConfigKey]
 		for _, svcKey := range services {
@@ -141,11 +146,7 @@ func parseBackendConfigName(ctx context.Context, val string) (string, bool) {
 func beConfigToGceServiceIR(beConfig *backendconfigv1.BackendConfig) intermediate.GceServiceIR {
 	var gceServiceIR intermediate.GceServiceIR
 	if beConfig.Spec.SessionAffinity != nil {
-		saConfig := intermediate.SessionAffinityConfig{
-			AffinityType: beConfig.Spec.SessionAffinity.AffinityType,
-			CookieTTLSec: beConfig.Spec.SessionAffinity.AffinityCookieTtlSec,
-		}
-		gceServiceIR.SessionAffinity = &saConfig
+		gceServiceIR.SessionAffinity = extensions.BuildIRSessionAffinityConfig(beConfig)
 	}
 
 	return gceServiceIR
@@ -167,32 +168,28 @@ func buildGceServiceExtensions(ir intermediate.IR, gatewayResources *i2gw.Gatewa
 }
 
 func addBackendPolicyIfConfigured(serviceNamespacedName types.NamespacedName, serviceIR intermediate.ProviderSpecificServiceIR) *gkegatewayv1.GCPBackendPolicy {
-	if serviceIR.Gce == nil || serviceIR.Gce.SessionAffinity == nil {
+	if serviceIR.Gce == nil {
 		return nil
 	}
-	affinityType := serviceIR.Gce.SessionAffinity.AffinityType
 	backendPolicy := gkegatewayv1.GCPBackendPolicy{
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: serviceNamespacedName.Namespace,
 			Name:      serviceNamespacedName.Name,
 		},
 		Spec: gkegatewayv1.GCPBackendPolicySpec{
-			Default: &gkegatewayv1.GCPBackendPolicyConfig{
-				SessionAffinity: &gkegatewayv1.SessionAffinityConfig{
-					Type: &affinityType,
-				},
-			},
+			Default: &gkegatewayv1.GCPBackendPolicyConfig{},
 			TargetRef: gatewayv1alpha2.NamespacedPolicyTargetReference{
 				Group: "",
 				Kind:  "Service",
 				Name:  gatewayv1.ObjectName(serviceNamespacedName.Name),
 			},
 		},
 	}
-	if affinityType == "GENERATED_COOKIE" {
-		backendPolicy.Spec.Default.SessionAffinity.CookieTTLSec = serviceIR.Gce.SessionAffinity.CookieTTLSec
+	backendPolicy.SetGroupVersionKind(GCPBackendPolicyGVK)
+
+	if serviceIR.Gce.SessionAffinity != nil {
+		backendPolicy.Spec.Default.SessionAffinity = extensions.BuildBackendPolicySessionAffinityConfig(serviceIR)
 	}
 
-	backendPolicy.SetGroupVersionKind(GCPBackendPolicyGVK)
 	return &backendPolicy
 }