modifyRecordAlias updates the AliasTarget of a specific DNS record in Route53.

gistfile1.txt

import (
    "fmt"
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/service/route53"
)

// modifyRecordAlias updates the AliasTarget of a specific DNS record in Route53.
func modifyRecordAlias(svc *route53.Route53, hostedZoneID, recordName, newTargetAlias string) error {
    fmt.Printf("Modifying AliasTarget for record %s in hosted zone %s\n", recordName, hostedZoneID)
    
    // First, find the record to modify
    input := &route53.ListResourceRecordSetsInput{
        HostedZoneId: aws.String(hostedZoneID),
    }
    result, err := svc.ListResourceRecordSets(input)
    if err != nil {
        return wrapError(err, "ListResourceRecordSets")
    }

    var targetRecord *route53.ResourceRecordSet
    for _, recordSet := range result.ResourceRecordSets {
        if *recordSet.Name == recordName + "." && recordSet.AliasTarget != nil {
            targetRecord = recordSet
            break
        }
    }
    
    if targetRecord == nil {
        return fmt.Errorf("record not found or is not an alias")
    }
    
    // Update the AliasTarget to point to the new DNS name
    targetRecord.AliasTarget.DNSName = aws.String(newTargetAlias)
    
    // Prepare the change batch for the update
    changeBatch := &route53.ChangeBatch{
        Changes: []*route53.Change{
            {
                Action:            aws.String("UPSERT"),
                ResourceRecordSet: targetRecord,
            },
        },
    }

    changeInput := &route53.ChangeResourceRecordSetsInput{
        HostedZoneId: aws.String(hostedZoneID),
        ChangeBatch:  changeBatch,
    }

    _, err = svc.ChangeResourceRecordSets(changeInput)
    if err != nil {
        return wrapError(err, "ChangeResourceRecordSets")
    }
    
    fmt.Printf("Successfully modified AliasTarget for record %s to %s\n", recordName, newTargetAlias)
    return nil
}

func TestModifyRecordAlias(t *testing.T) {
    // Create a new AWS session (you would normally restrict this to a specific region)
    sess := session.Must(session.NewSession(&aws.Config{
        Region: aws.String("us-west-2"), // Example region
    }))
    svc := route53.New(sess)

    // Assuming you have valid hostedZoneID, recordName, and newTargetAlias
    hostedZoneID := "valid-hosted-zone-id"
    recordName := "valid-record-name.example.com"
    newTargetAlias := "new-target-alias.example.com"

    // Call the function (this will make a real API call, be careful with this)
    err := route53manager.ModifyRecordAlias(svc, hostedZoneID, recordName, newTargetAlias)

    // Check for errors
    if err != nil {
        t.Errorf("Expected no error, got %v", err)
    }
}