fix: Cannot set the IPv6 addresses in dualstack mode during modification

Author: wweiwei-li

pkg/deploy/elbv2/load_balancer_manager.go

@@ -158,20 +158,28 @@ func (m *defaultLoadBalancerManager) updateSDKLoadBalancerWithIPAddressType(ctx
 
 func (m *defaultLoadBalancerManager) updateSDKLoadBalancerWithSubnetMappings(ctx context.Context, resLB *elbv2model.LoadBalancer, sdkLB LoadBalancerWithTags) error {
 	desiredSubnets := sets.NewString()
+	desiredIPv6Addresses := sets.NewString()
 	desiredSubnetsSourceNATPrefixes := sets.NewString()
 	currentSubnetsSourceNATPrefixes := sets.NewString()
 	for _, mapping := range resLB.Spec.SubnetMappings {
 		desiredSubnets.Insert(mapping.SubnetID)
 		if mapping.SourceNatIpv6Prefix != nil {
 			desiredSubnetsSourceNATPrefixes.Insert(awssdk.ToString(mapping.SourceNatIpv6Prefix))
 		}
+		if mapping.IPv6Address != nil {
+			desiredIPv6Addresses.Insert(awssdk.ToString(mapping.IPv6Address))
+		}
 	}
 	currentSubnets := sets.NewString()
+	currentIPv6Addresses := sets.NewString()
 	for _, az := range sdkLB.LoadBalancer.AvailabilityZones {
 		currentSubnets.Insert(awssdk.ToString(az.SubnetId))
 		if len(az.SourceNatIpv6Prefixes) != 0 {
 			currentSubnetsSourceNATPrefixes.Insert(az.SourceNatIpv6Prefixes[0])
 		}
+		if len(az.LoadBalancerAddresses) > 0 && az.LoadBalancerAddresses[0].IPv6Address != nil {
+			currentIPv6Addresses.Insert(awssdk.ToString(az.LoadBalancerAddresses[0].IPv6Address))
+		}
 	}
 	sdkLBEnablePrefixForIpv6SourceNatValue := string(elbv2model.EnablePrefixForIpv6SourceNatOff)
 	resLBEnablePrefixForIpv6SourceNatValue := string(elbv2model.EnablePrefixForIpv6SourceNatOff)
@@ -180,7 +188,9 @@ func (m *defaultLoadBalancerManager) updateSDKLoadBalancerWithSubnetMappings(ctx
 
 	resLBEnablePrefixForIpv6SourceNatValue = string(resLB.Spec.EnablePrefixForIpv6SourceNat)
 
-	if desiredSubnets.Equal(currentSubnets) && desiredSubnetsSourceNATPrefixes.Equal(currentSubnetsSourceNATPrefixes) && ((sdkLBEnablePrefixForIpv6SourceNatValue == resLBEnablePrefixForIpv6SourceNatValue) || (resLBEnablePrefixForIpv6SourceNatValue == "")) {
+	isFirstTimeIPv6Setup := currentIPv6Addresses.Len() == 0 && desiredIPv6Addresses.Len() > 0
+	needsDualstackIPv6Update := isIPv4ToDualstackUpdate(resLB, sdkLB) && isFirstTimeIPv6Setup
+	if !needsDualstackIPv6Update && desiredSubnets.Equal(currentSubnets) && desiredSubnetsSourceNATPrefixes.Equal(currentSubnetsSourceNATPrefixes) && ((sdkLBEnablePrefixForIpv6SourceNatValue == resLBEnablePrefixForIpv6SourceNatValue) || (resLBEnablePrefixForIpv6SourceNatValue == "")) {
 		return nil
 	}
 	req := &elbv2sdk.SetSubnetsInput{
@@ -355,3 +365,15 @@ func isEnforceSGInboundRulesOnPrivateLinkUpdated(resLB *elbv2model.LoadBalancer,
 	return true, currentEnforceSecurityGroupInboundRulesOnPrivateLinkTraffic, desiredEnforceSecurityGroupInboundRulesOnPrivateLinkTraffic
 
 }
+
+func isIPv4ToDualstackUpdate(resLB *elbv2model.LoadBalancer, sdkLB LoadBalancerWithTags) bool {
+	if &resLB.Spec.IPAddressType == nil {
+		return false
+	}
+	desiredIPAddressType := string(resLB.Spec.IPAddressType)
+	currentIPAddressType := sdkLB.LoadBalancer.IpAddressType
+	isIPAddressTypeUpdated := desiredIPAddressType != string(currentIPAddressType)
+	return isIPAddressTypeUpdated &&
+		resLB.Spec.Type == elbv2model.LoadBalancerTypeNetwork &&
+		desiredIPAddressType == string(elbv2model.IPAddressTypeDualStack)
+}

pkg/deploy/elbv2/load_balancer_manager_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	elbv2types "github.com/aws/aws-sdk-go-v2/service/elasticloadbalancingv2/types"
+	"github.com/aws/aws-sdk-go/aws"
 	"github.com/go-logr/logr"
 	"sigs.k8s.io/aws-load-balancer-controller/pkg/aws/services"
 
@@ -612,6 +613,55 @@ func Test_defaultLoadBalancerManager_updateSDKLoadBalancerWithSubnetMappings(t *
 			},
 			wantErr: nil,
 		},
+		{
+			name: "Set NLB IPv6 address in dualstack mode during ip address type modification ",
+			fields: fields{
+				setSubnetsWithContextCall: setSubnetsWithContextCall{
+					req: &elbv2sdk.SetSubnetsInput{
+						LoadBalancerArn: awssdk.String("LoadBalancerArn"),
+						SubnetMappings: []elbv2types.SubnetMapping{
+							{
+								SubnetId:    awssdk.String("subnet-A"),
+								IPv6Address: aws.String("2600:1f18::1"),
+							},
+							{
+								SubnetId:    awssdk.String("subnet-B"),
+								IPv6Address: aws.String("2600:1f18::2"),
+							},
+						},
+					},
+					resp: &elbv2sdk.SetSubnetsOutput{},
+				},
+			},
+			args: args{
+				resLB: &elbv2model.LoadBalancer{
+					ResourceMeta: coremodel.NewResourceMeta(stack, "AWS::ElasticLoadBalancingV2::LoadBalancer", "id-1"),
+					Spec: elbv2model.LoadBalancerSpec{
+						SubnetMappings: []elbv2model.SubnetMapping{
+							{
+								SubnetID:    "subnet-A",
+								IPv6Address: aws.String("2600:1f18::1"),
+							},
+							{
+								SubnetID:    "subnet-B",
+								IPv6Address: aws.String("2600:1f18::2"),
+							},
+						},
+						Type:          elbv2model.LoadBalancerTypeNetwork,
+						IPAddressType: elbv2model.IPAddressTypeDualStack,
+					},
+				},
+				sdkLB: LoadBalancerWithTags{
+					LoadBalancer: &elbv2types.LoadBalancer{
+						LoadBalancerArn:   awssdk.String("LoadBalancerArn"),
+						Type:              elbv2types.LoadBalancerTypeEnumNetwork,
+						AvailabilityZones: []elbv2types.AvailabilityZone{{SubnetId: awssdk.String("subnet-A")}, {SubnetId: awssdk.String("subnet-B")}},
+						IpAddressType:     elbv2types.IpAddressTypeIpv4,
+					},
+				},
+			},
+			wantErr: nil,
+		},
 	}
 
 	for _, tt := range tests {
@@ -632,6 +682,7 @@ func Test_defaultLoadBalancerManager_updateSDKLoadBalancerWithSubnetMappings(t *
 			} else {
 				assert.NoError(t, err)
 			}
+
 		})
 	}
 }