Fix AWS NLB security group updates

pkg/cloudprovider/providers/aws/aws_loadbalancer.go

@@ -569,12 +569,17 @@ func filterForIPRangeDescription(securityGroups []*ec2.SecurityGroup, lbName str
 	response := []*ec2.SecurityGroup{}
 	clientRule := fmt.Sprintf("%s=%s", NLBClientRuleDescription, lbName)
 	healthRule := fmt.Sprintf("%s=%s", NLBHealthCheckRuleDescription, lbName)
+	alreadyAdded := sets.NewString()
 	for i := range securityGroups {
 		for j := range securityGroups[i].IpPermissions {
 			for k := range securityGroups[i].IpPermissions[j].IpRanges {
 				description := aws.StringValue(securityGroups[i].IpPermissions[j].IpRanges[k].Description)
 				if description == clientRule || description == healthRule {
-					response = append(response, securityGroups[i])
+					sgIDString := aws.StringValue(securityGroups[i].GroupId)
+					if !alreadyAdded.Has(sgIDString) {
+						response = append(response, securityGroups[i])
+						alreadyAdded.Insert(sgIDString)
+					}
 				}
 			}
 		}
@@ -599,6 +604,7 @@ func (c *Cloud) getVpcCidrBlock() (*string, error) {
 // if clientTraffic is false, then only update HealthCheck rules
 func (c *Cloud) updateInstanceSecurityGroupsForNLBTraffic(actualGroups []*ec2.SecurityGroup, desiredSgIds []string, ports []int64, lbName string, clientCidrs []string, clientTraffic bool) error {
 
+	klog.V(8).Infof("updateInstanceSecurityGroupsForNLBTraffic: actualGroups=%v, desiredSgIds=%v, ports=%v, clientTraffic=%v", actualGroups, desiredSgIds, ports, clientTraffic)
 	// Map containing the groups we want to make changes on; the ports to make
 	// changes on; and whether to add or remove it. true to add, false to remove
 	portChanges := map[string]map[int64]bool{}
@@ -653,16 +659,16 @@ func (c *Cloud) updateInstanceSecurityGroupsForNLBTraffic(actualGroups []*ec2.Se
 			if add {
 				if clientTraffic {
 					klog.V(2).Infof("Adding rule for client MTU discovery from the network load balancer (%s) to instances (%s)", clientCidrs, instanceSecurityGroupID)
-					klog.V(2).Infof("Adding rule for client traffic from the network load balancer (%s) to instances (%s)", clientCidrs, instanceSecurityGroupID)
+					klog.V(2).Infof("Adding rule for client traffic from the network load balancer (%s) to instances (%s), port (%v)", clientCidrs, instanceSecurityGroupID, port)
 				} else {
-					klog.V(2).Infof("Adding rule for health check traffic from the network load balancer (%s) to instances (%s)", clientCidrs, instanceSecurityGroupID)
+					klog.V(2).Infof("Adding rule for health check traffic from the network load balancer (%s) to instances (%s), port (%v)", clientCidrs, instanceSecurityGroupID, port)
 				}
 			} else {
 				if clientTraffic {
 					klog.V(2).Infof("Removing rule for client MTU discovery from the network load balancer (%s) to instances (%s)", clientCidrs, instanceSecurityGroupID)
-					klog.V(2).Infof("Removing rule for client traffic from the network load balancer (%s) to instance (%s)", clientCidrs, instanceSecurityGroupID)
+					klog.V(2).Infof("Removing rule for client traffic from the network load balancer (%s) to instance (%s), port (%v)", clientCidrs, instanceSecurityGroupID, port)
 				}
-				klog.V(2).Infof("Removing rule for health check traffic from the network load balancer (%s) to instance (%s)", clientCidrs, instanceSecurityGroupID)
+				klog.V(2).Infof("Removing rule for health check traffic from the network load balancer (%s) to instance (%s), port (%v)", clientCidrs, instanceSecurityGroupID, port)
 			}
 
 			if clientTraffic {