@@ -25,6 +25,7 @@ import (
2525
2626 "github.com/aws/aws-sdk-go/aws"
2727 "github.com/aws/aws-sdk-go/service/ec2"
28+ "github.com/aws/aws-sdk-go/service/ec2/ec2iface"
2829 "github.com/pkg/errors"
2930 "k8s.io/utils/ptr"
3031
@@ -913,6 +914,8 @@ func (s *Service) SDKToInstance(v *ec2.Instance) (*infrav1.Instance, error) {
913914
914915func (s * Service ) getInstanceAddresses (instance * ec2.Instance ) []clusterv1.MachineAddress {
915916 addresses := []clusterv1.MachineAddress {}
917+ // Check if the DHCP Option Set has domain name set
918+ domainName := s .GetDHCPOptionSetDomainName (s .EC2Client , instance .VpcId )
916919 for _ , eni := range instance .NetworkInterfaces {
917920 privateDNSAddress := clusterv1.MachineAddress {
918921 Type : clusterv1 .MachineInternalDNS ,
@@ -922,8 +925,18 @@ func (s *Service) getInstanceAddresses(instance *ec2.Instance) []clusterv1.Machi
922925 Type : clusterv1 .MachineInternalIP ,
923926 Address : aws .StringValue (eni .PrivateIpAddress ),
924927 }
928+
925929 addresses = append (addresses , privateDNSAddress , privateIPAddress )
926930
931+ if domainName != nil {
932+ // Add secondary private DNS Name with domain name set in DHCP Option Set
933+ additionalPrivateDNSAddress := clusterv1.MachineAddress {
934+ Type : clusterv1 .MachineInternalDNS ,
935+ Address : fmt .Sprintf ("%s.%s" , strings .Split (privateDNSAddress .Address , "." )[0 ], * domainName ),
936+ }
937+ addresses = append (addresses , additionalPrivateDNSAddress )
938+ }
939+
927940 // An elastic IP is attached if association is non nil pointer
928941 if eni .Association != nil {
929942 publicDNSAddress := clusterv1.MachineAddress {
@@ -937,6 +950,7 @@ func (s *Service) getInstanceAddresses(instance *ec2.Instance) []clusterv1.Machi
937950 addresses = append (addresses , publicDNSAddress , publicIPAddress )
938951 }
939952 }
953+
940954 return addresses
941955}
942956
@@ -1035,6 +1049,54 @@ func (s *Service) ModifyInstanceMetadataOptions(instanceID string, options *infr
10351049 return nil
10361050}
10371051
1052+ // GetDHCPOptionSetDomainName returns the domain DNS name for the VPC from the DHCP Options.
1053+ func (s * Service ) GetDHCPOptionSetDomainName (ec2client ec2iface.EC2API , vpcID * string ) * string {
1054+ log := s .scope .GetLogger ()
1055+
1056+ if vpcID == nil {
1057+ log .Info ("vpcID is nil, skipping DHCP Option Set discovery" )
1058+ return nil
1059+ }
1060+
1061+ vpcInput := & ec2.DescribeVpcsInput {
1062+ VpcIds : []* string {vpcID },
1063+ }
1064+
1065+ vpcResult , err := ec2client .DescribeVpcs (vpcInput )
1066+ if err != nil {
1067+ log .Info ("failed to describe VPC, skipping DHCP Option Set discovery" , "vpcID" , * vpcID , "Error" , err .Error ())
1068+ return nil
1069+ }
1070+
1071+ dhcpInput := & ec2.DescribeDhcpOptionsInput {
1072+ DhcpOptionsIds : []* string {vpcResult .Vpcs [0 ].DhcpOptionsId },
1073+ }
1074+
1075+ dhcpResult , err := ec2client .DescribeDhcpOptions (dhcpInput )
1076+ if err != nil {
1077+ log .Error (err , "failed to describe DHCP Options Set" , "DhcpOptionsSet" , * dhcpResult )
1078+ return nil
1079+ }
1080+
1081+ for _ , dhcpConfig := range dhcpResult .DhcpOptions [0 ].DhcpConfigurations {
1082+ if * dhcpConfig .Key == "domain-name" {
1083+ if len (dhcpConfig .Values ) == 0 {
1084+ return nil
1085+ }
1086+ domainName := dhcpConfig .Values [0 ].Value
1087+ // default domainName is 'ec2.internal' in us-east-1 and 'region.compute.internal' in the other regions.
1088+ if (s .scope .Region () == "us-east-1" && * domainName == "ec2.internal" ) ||
1089+ (s .scope .Region () != "us-east-1" && * domainName == fmt .Sprintf ("%s.compute.internal" , s .scope .Region ())) {
1090+ return nil
1091+ }
1092+
1093+ return domainName
1094+ }
1095+ }
1096+
1097+ return nil
1098+ }
1099+
10381100// filterGroups filters a list for a string.
10391101func filterGroups (list []string , strToFilter string ) (newList []string ) {
10401102 for _ , item := range list {
0 commit comments