CORS-4332: Add GCP to the allowed platforms for dual stack

Added GCP as a platform that supports DualStack on Day-0
Added GCP as a platform that does not support conversion to DualStack on Day-2
Added tests for GCP

** GCP is behind a featuregate. Ensure that these featuregates are enablede before
dual stack support is extended to GCP.

Author: barbacbd

pkg/network/cluster_config_test.go

@@ -38,7 +38,9 @@ func getFeatureGatesWithDualStack() featuregates.FeatureGate {
 			apifeatures.FeatureGateDNSNameResolver,
 			apifeatures.FeatureGateOVNObservability,
 			apifeatures.FeatureGateAWSDualStackInstall,
-			apifeatures.FeatureGateAzureDualStackInstall},
+			apifeatures.FeatureGateAzureDualStackInstall,
+			apifeatures.FeatureGateGCPDualStackInstall,
+		},
 		[]configv1.FeatureGateName{},
 	)
 }
@@ -122,6 +124,7 @@ func getFeatureGatesWithIncompleteDualStack() featuregates.FeatureGate {
 		},
 		[]configv1.FeatureGateName{
 			apifeatures.FeatureGateAzureDualStackInstall,
+			apifeatures.FeatureGateGCPDualStackInstall,
 		},
 	)
 }
@@ -195,10 +198,10 @@ func TestValidateClusterConfigDualStack(t *testing.T) {
 	err = ValidateClusterConfig(&configv1.Network{Spec: cc}, client, featureGates)
 	g.Expect(err).NotTo(HaveOccurred())
 
-	// You can't use dual-stack if enabled on an unsupported platform
-	infrastructure.Status.PlatformStatus.Type = configv1.GCPPlatformType
-	infrastructure.Status.PlatformStatus.GCP = &configv1.GCPPlatformStatus{
-		Region: "us-west1",
+	// DualStack supported only with featuregates
+	infrastructure.Status.PlatformStatus.Type = configv1.AWSPlatformType
+	infrastructure.Status.PlatformStatus.AWS = &configv1.AWSPlatformStatus{
+		Region: "us-east-1",
 	}
 	client = fake.NewFakeClient(infrastructure)
 	err = createProxy(client)
@@ -209,14 +212,13 @@ func TestValidateClusterConfigDualStack(t *testing.T) {
 		CIDR:       "fd01::/48",
 		HostPrefix: 64,
 	})
-	haveError(cc, fmt.Sprintf("%s is not one of the supported platforms for dual stack",
-		infrastructure.Status.PlatformStatus.Type))
+	err = ValidateClusterConfig(&configv1.Network{Spec: cc}, client, featureGates)
+	g.Expect(err).NotTo(HaveOccurred())
 
-	// DualStack supported only with featuregates
-	infrastructure.Status.PlatformStatus.Type = configv1.AWSPlatformType
-	infrastructure.Status.PlatformStatus.AWS = &configv1.AWSPlatformStatus{
-		Region: "us-east-1",
-	}
+	// DualStack with supported platform but missing featuregate
+	featureGates = getFeatureGatesWithIncompleteDualStack()
+	infrastructure.Status.PlatformStatus.Type = configv1.AzurePlatformType
+	infrastructure.Status.PlatformStatus.Azure = &configv1.AzurePlatformStatus{}
 	client = fake.NewFakeClient(infrastructure)
 	err = createProxy(client)
 	g.Expect(err).NotTo(HaveOccurred())
@@ -227,12 +229,13 @@ func TestValidateClusterConfigDualStack(t *testing.T) {
 		HostPrefix: 64,
 	})
 	err = ValidateClusterConfig(&configv1.Network{Spec: cc}, client, featureGates)
-	g.Expect(err).NotTo(HaveOccurred())
+	haveError(cc, fmt.Sprintf("%s is not one of the supported platforms for dual stack",
+		infrastructure.Status.PlatformStatus.Type))
 
 	// DualStack with supported platform but missing featuregate
 	featureGates = getFeatureGatesWithIncompleteDualStack()
-	infrastructure.Status.PlatformStatus.Type = configv1.AzurePlatformType
-	infrastructure.Status.PlatformStatus.Azure = &configv1.AzurePlatformStatus{}
+	infrastructure.Status.PlatformStatus.Type = configv1.GCPPlatformType
+	infrastructure.Status.PlatformStatus.GCP = &configv1.GCPPlatformStatus{}
 	client = fake.NewFakeClient(infrastructure)
 	err = createProxy(client)
 	g.Expect(err).NotTo(HaveOccurred())

pkg/network/render.go

@@ -908,7 +908,7 @@ func renderAdditionalRoutingCapabilities(conf *operv1.NetworkSpec, manifestDir s
 }
 
 // isSupportedDualStackPlatform returns true if the platform supports dual-stack networking
-// on Day-0 (initial cluster installation). Some platforms (AWS, Azure) require feature gates
+// on Day-0 (initial cluster installation). Some platforms (AWS, Azure, GCP) require feature gates
 // to be enabled to support dual-stack.
 func isSupportedDualStackPlatform(platformType configv1.PlatformType, featureGates featuregates.FeatureGate) bool {
 	switch platformType {
@@ -918,6 +918,8 @@ func isSupportedDualStackPlatform(platformType configv1.PlatformType, featureGat
 		return featureGates.Enabled(apifeatures.FeatureGateAWSDualStackInstall)
 	case configv1.AzurePlatformType:
 		return featureGates.Enabled(apifeatures.FeatureGateAzureDualStackInstall)
+	case configv1.GCPPlatformType:
+		return featureGates.Enabled(apifeatures.FeatureGateGCPDualStackInstall)
 	default:
 		return false
 	}

pkg/network/render_test.go

@@ -219,6 +219,7 @@ func TestAllowMigrationOnlyForSupportedTypes(t *testing.T) {
 		HostPrefix: 64,
 	},
 	)
+
 	// You can't migrate from single-stack to dual-stack if this is anything else but
 	// BareMetal, NonePlatformType, and VSphere
 	infra.PlatformType = configv1.GCPPlatformType
@@ -330,7 +331,9 @@ func getDefaultFeatureGatesWithDualStack() featuregates.FeatureGate {
 		[]configv1.FeatureGateName{apifeatures.FeatureGateDNSNameResolver,
 			apifeatures.FeatureGateOVNObservability,
 			apifeatures.FeatureGateAWSDualStackInstall,
-			apifeatures.FeatureGateAzureDualStackInstall},
+			apifeatures.FeatureGateAzureDualStackInstall,
+			apifeatures.FeatureGateGCPDualStackInstall,
+		},
 		[]configv1.FeatureGateName{},
 	)
 }