add multi-zone capability to google provider (take 2) (#163)

* feat(google): auto-detect and multiple zone support

* chore: run gofmt with the simplified command

* fix: pass desired domain to google provider

* feat(google): correctly auto-detect records for sub-zones

* chore: update changelog with support for multiple zones in google

* fix(google): don't append traling dot to TXT records

* ref(provider): extract hostname sanitization to general provider

CHANGELOG.md

@@ -1,7 +1,7 @@
 Features:
   - Improved logging
   - Generate DNS Name from template for services/ingress if annotation is missing but `--fqdn-template` is specified
-  - Route 53: Support creation of records in multiple hosted zones.
+  - Route 53, Google CloudDNS: Support creation of records in multiple hosted zones.
   - Route 53: Support creation of ALIAS records when endpoint target is a ELB/ALB.
   - Ownership via TXT records
     1. Create TXT records to mark the records managed by External DNS

main.go

@@ -105,7 +105,7 @@ func main() {
 	var p provider.Provider
 	switch cfg.Provider {
 	case "google":
-		p, err = provider.NewGoogleProvider(cfg.GoogleProject, cfg.DryRun)
+		p, err = provider.NewGoogleProvider(cfg.GoogleProject, cfg.Domain, cfg.DryRun)
 	case "aws":
 		p, err = provider.NewAWSProvider(cfg.Domain, cfg.DryRun)
 	default:

provider/aws.go

@@ -17,7 +17,6 @@ limitations under the License.
 package provider
 
 import (
-	"net"
 	"strings"
 
 	log "github.com/Sirupsen/logrus"
@@ -327,12 +326,3 @@ func canonicalHostedZone(hostname string) string {
 
 	return ""
 }
-
-// ensureTrailingDot ensures that the hostname receives a trailing dot if it hasn't already.
-func ensureTrailingDot(hostname string) string {
-	if net.ParseIP(hostname) != nil {
-		return hostname
-	}
-
-	return strings.TrimSuffix(hostname, ".") + "."
-}

provider/google.go

@@ -17,6 +17,8 @@ limitations under the License.
 package provider
 
 import (
+	"strings"
+
 	log "github.com/Sirupsen/logrus"
 
 	"golang.org/x/net/context"
@@ -33,17 +35,12 @@ type managedZonesCreateCallInterface interface {
 	Do(opts ...googleapi.CallOption) (*dns.ManagedZone, error)
 }
 
-type managedZonesDeleteCallInterface interface {
-	Do(opts ...googleapi.CallOption) error
-}
-
 type managedZonesListCallInterface interface {
 	Pages(ctx context.Context, f func(*dns.ManagedZonesListResponse) error) error
 }
 
 type managedZonesServiceInterface interface {
 	Create(project string, managedzone *dns.ManagedZone) managedZonesCreateCallInterface
-	Delete(project string, managedZone string) managedZonesDeleteCallInterface
 	List(project string) managedZonesListCallInterface
 }
 
@@ -79,10 +76,6 @@ func (m managedZonesService) Create(project string, managedzone *dns.ManagedZone
 	return m.service.Create(project, managedzone)
 }
 
-func (m managedZonesService) Delete(project string, managedZone string) managedZonesDeleteCallInterface {
-	return m.service.Delete(project, managedZone)
-}
-
 func (m managedZonesService) List(project string) managedZonesListCallInterface {
 	return m.service.List(project)
 }
@@ -101,6 +94,8 @@ type googleProvider struct {
 	project string
 	// Enabled dry-run will print any modifying actions rather than execute them.
 	dryRun bool
+	// only consider hosted zones managing domains ending in this suffix
+	domain string
 	// A client for managing resource record sets
 	resourceRecordSetsClient resourceRecordSetsClientInterface
 	// A client for managing hosted zones
@@ -110,7 +105,7 @@ type googleProvider struct {
 }
 
 // NewGoogleProvider initializes a new Google CloudDNS based Provider.
-func NewGoogleProvider(project string, dryRun bool) (Provider, error) {
+func NewGoogleProvider(project string, domain string, dryRun bool) (Provider, error) {
 	gcloud, err := google.DefaultClient(context.TODO(), dns.NdevClouddnsReadwriteScope)
 	if err != nil {
 		return nil, err
@@ -123,6 +118,7 @@ func NewGoogleProvider(project string, dryRun bool) (Provider, error) {
 
 	provider := &googleProvider{
 		project: project,
+		domain:  domain,
 		dryRun:  dryRun,
 		resourceRecordSetsClient: resourceRecordSetsService{dnsClient.ResourceRecordSets},
 		managedZonesClient:       managedZonesService{dnsClient.ManagedZones},
@@ -133,49 +129,33 @@ func NewGoogleProvider(project string, dryRun bool) (Provider, error) {
 }
 
 // Zones returns the list of hosted zones.
-func (p *googleProvider) Zones() (zones []*dns.ManagedZone, _ error) {
+func (p *googleProvider) Zones() (map[string]*dns.ManagedZone, error) {
+	zones := make(map[string]*dns.ManagedZone)
+
 	f := func(resp *dns.ManagedZonesListResponse) error {
-		// each page is processed sequentially, no need for a mutex here.
+		for _, zone := range resp.ManagedZones {
-		zones = append(zones, resp.ManagedZones...)
+			if strings.HasSuffix(zone.DnsName, p.domain) {
+				zones[zone.Name] = zone
+			}
+		}
+
 		return nil
 	}
 
-	err := p.managedZonesClient.List(p.project).Pages(context.TODO(), f)
+	if err := p.managedZonesClient.List(p.project).Pages(context.TODO(), f); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
 	return zones, nil
 }
 
-// CreateZone creates a hosted zone given a name.
+// Records returns the list of records in all relevant zones.
-func (p *googleProvider) CreateZone(name, domain string) error {
+func (p *googleProvider) Records(_ string) (endpoints []*endpoint.Endpoint, _ error) {
-	zone := &dns.ManagedZone{
+	zones, err := p.Zones()
-		Name:        name,
-		DnsName:     domain,
-		Description: "Automatically managed zone by kubernetes.io/external-dns",
-	}
-
-	_, err := p.managedZonesClient.Create(p.project, zone).Do()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	return nil
-}
-
-// DeleteZone deletes a hosted zone given a name.
-func (p *googleProvider) DeleteZone(name string) error {
-	err := p.managedZonesClient.Delete(p.project, name).Do()
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-// Records returns the list of A records in a given hosted zone.
-func (p *googleProvider) Records(zone string) (endpoints []*endpoint.Endpoint, _ error) {
 	f := func(resp *dns.ResourceRecordSetsListResponse) error {
 		for _, r := range resp.Rrsets {
 			// TODO(linki, ownership): Remove once ownership system is in place.
@@ -196,44 +176,45 @@ func (p *googleProvider) Records(zone string) (endpoints []*endpoint.Endpoint, _
 		return nil
 	}
 
-	err := p.resourceRecordSetsClient.List(p.project, zone).Pages(context.TODO(), f)
+	for _, z := range zones {
-	if err != nil {
+		if err := p.resourceRecordSetsClient.List(p.project, z.Name).Pages(context.TODO(), f); err != nil {
-		return nil, err
+			return nil, err
+		}
 	}
 
 	return endpoints, nil
 }
 
 // CreateRecords creates a given set of DNS records in the given hosted zone.
-func (p *googleProvider) CreateRecords(zone string, endpoints []*endpoint.Endpoint) error {
+func (p *googleProvider) CreateRecords(endpoints []*endpoint.Endpoint) error {
 	change := &dns.Change{}
 
 	change.Additions = append(change.Additions, newRecords(endpoints)...)
 
-	return p.submitChange(zone, change)
+	return p.submitChange(change)
 }
 
 // UpdateRecords updates a given set of old records to a new set of records in a given hosted zone.
-func (p *googleProvider) UpdateRecords(zone string, records, oldRecords []*endpoint.Endpoint) error {
+func (p *googleProvider) UpdateRecords(records, oldRecords []*endpoint.Endpoint) error {
 	change := &dns.Change{}
 
 	change.Additions = append(change.Additions, newRecords(records)...)
 	change.Deletions = append(change.Deletions, newRecords(oldRecords)...)
 
-	return p.submitChange(zone, change)
+	return p.submitChange(change)
 }
 
 // DeleteRecords deletes a given set of DNS records in a given zone.
-func (p *googleProvider) DeleteRecords(zone string, endpoints []*endpoint.Endpoint) error {
+func (p *googleProvider) DeleteRecords(endpoints []*endpoint.Endpoint) error {
 	change := &dns.Change{}
 
 	change.Deletions = append(change.Deletions, newRecords(endpoints)...)
 
-	return p.submitChange(zone, change)
+	return p.submitChange(change)
 }
 
 // ApplyChanges applies a given set of changes in a given zone.
-func (p *googleProvider) ApplyChanges(zone string, changes *plan.Changes) error {
+func (p *googleProvider) ApplyChanges(_ string, changes *plan.Changes) error {
 	change := &dns.Change{}
 
 	change.Additions = append(change.Additions, newRecords(changes.Create)...)
@@ -243,12 +224,11 @@ func (p *googleProvider) ApplyChanges(zone string, changes *plan.Changes) error
 
 	change.Deletions = append(change.Deletions, newRecords(changes.Delete)...)
 
-	return p.submitChange(zone, change)
+	return p.submitChange(change)
 }
 
 // submitChange takes a zone and a Change and sends it to Google.
-func (p *googleProvider) submitChange(zone string, change *dns.Change) error {
+func (p *googleProvider) submitChange(change *dns.Change) error {
-
 	if len(change.Additions) == 0 && len(change.Deletions) == 0 {
 		log.Infoln("Received empty list of records for creation and deletion")
 		return nil
@@ -261,9 +241,20 @@ func (p *googleProvider) submitChange(zone string, change *dns.Change) error {
 		log.Infof("Add records: %s %s %s", add.Name, add.Type, add.Rrdatas)
 	}
 
-	if !p.dryRun {
+	if p.dryRun {
-		_, err := p.changesClient.Create(p.project, zone, change).Do()
+		return nil
-		if err != nil {
+	}
+
+	zones, err := p.Zones()
+	if err != nil {
+		return err
+	}
+
+	// separate into per-zone change sets to be passed to the API.
+	changes := separateChange(zones, change)
+
+	for z, c := range changes {
+		if _, err := p.changesClient.Create(p.project, z, c).Do(); err != nil {
 			return err
 		}
 	}
@@ -271,6 +262,54 @@ func (p *googleProvider) submitChange(zone string, change *dns.Change) error {
 	return nil
 }
 
+// separateChange separates a multi-zone change into a single change per zone.
+func separateChange(zones map[string]*dns.ManagedZone, change *dns.Change) map[string]*dns.Change {
+	changes := make(map[string]*dns.Change)
+
+	for _, z := range zones {
+		changes[z.Name] = &dns.Change{
+			Additions: []*dns.ResourceRecordSet{},
+			Deletions: []*dns.ResourceRecordSet{},
+		}
+	}
+
+	for _, a := range change.Additions {
+		if zone := suitableManagedZone(ensureTrailingDot(a.Name), zones); zone != nil {
+			changes[zone.Name].Additions = append(changes[zone.Name].Additions, a)
+		}
+	}
+
+	for _, d := range change.Deletions {
+		if zone := suitableManagedZone(ensureTrailingDot(d.Name), zones); zone != nil {
+			changes[zone.Name].Deletions = append(changes[zone.Name].Deletions, d)
+		}
+	}
+
+	// separating a change could lead to empty sub changes, remove them here.
+	for zone, change := range changes {
+		if len(change.Additions) == 0 && len(change.Deletions) == 0 {
+			delete(changes, zone)
+		}
+	}
+
+	return changes
+}
+
+// suitableManagedZone returns the most suitable zone for a given hostname and a set of zones.
+func suitableManagedZone(hostname string, zones map[string]*dns.ManagedZone) *dns.ManagedZone {
+	var zone *dns.ManagedZone
+
+	for _, z := range zones {
+		if strings.HasSuffix(hostname, z.DnsName) {
+			if zone == nil || len(z.DnsName) > len(zone.DnsName) {
+				zone = z
+			}
+		}
+	}
+
+	return zone
+}
+
 // newRecords returns a collection of RecordSets based on the given endpoints.
 func newRecords(endpoints []*endpoint.Endpoint) []*dns.ResourceRecordSet {
 	records := make([]*dns.ResourceRecordSet, len(endpoints))
@@ -284,9 +323,17 @@ func newRecords(endpoints []*endpoint.Endpoint) []*dns.ResourceRecordSet {
 
 // newRecord returns a RecordSet based on the given endpoint.
 func newRecord(endpoint *endpoint.Endpoint) *dns.ResourceRecordSet {
+	// TODO(linki): works around appending a trailing dot to TXT records. I think
+	// we should go back to storing DNS names with a trailing dot internally. This
+	// way we can use it has is here and trim it off if it exists when necessary.
+	target := endpoint.Target
+	if suitableType(endpoint) == "CNAME" {
+		target = ensureTrailingDot(target)
+	}
+
 	return &dns.ResourceRecordSet{
 		Name:    ensureTrailingDot(endpoint.DNSName),
-		Rrdatas: []string{ensureTrailingDot(endpoint.Target)},
+		Rrdatas: []string{target},
 		Ttl:     300,
 		Type:    suitableType(endpoint),
 	}

provider/google_test.go

@@ -18,6 +18,8 @@ package provider
 
 import (
 	"fmt"
+	"net/http"
+	"strings"
 	"testing"
 
 	"golang.org/x/net/context"
@@ -25,320 +27,603 @@ import (
 	"github.com/kubernetes-incubator/external-dns/endpoint"
 	"github.com/kubernetes-incubator/external-dns/plan"
 
-	dns "google.golang.org/api/dns/v1"
+	"google.golang.org/api/dns/v1"
-	googleapi "google.golang.org/api/googleapi"
+	"google.golang.org/api/googleapi"
 )
 
 var (
-	expectedZones      = []*dns.ManagedZone{{Name: "expected"}}
+	testZones   = map[string]*dns.ManagedZone{}
-	expectedRecordSets = []*dns.ResourceRecordSet{
+	testRecords = map[string]map[string]*dns.ResourceRecordSet{}
-		{
-			Type:    "A",
-			Name:    "expected-1",
-			Rrdatas: []string{"8.8.8.8"},
-		},
-		{
-			Type:    "CNAME",
-			Name:    "expected-2",
-			Rrdatas: []string{"target.com"},
-		},
-		{
-			Type:    "NS",
-			Name:    "unexpected",
-			Rrdatas: []string{"target"},
-		},
-	}
 )
 
-type mockManagedZonesCreateCall struct{}
+type mockManagedZonesCreateCall struct {
+	project     string
+	managedZone *dns.ManagedZone
+}
 
 func (m *mockManagedZonesCreateCall) Do(opts ...googleapi.CallOption) (*dns.ManagedZone, error) {
-	return nil, nil
+	zoneKey := zoneKey(m.project, m.managedZone.Name)
+
+	if _, ok := testZones[zoneKey]; ok {
+		return nil, &googleapi.Error{Code: http.StatusConflict}
+	}
+
+	testZones[zoneKey] = m.managedZone
+
+	return m.managedZone, nil
 }
 
-type mockErrManagedZonesCreateCall struct{}
+type mockManagedZonesListCall struct {
-
+	project string
-func (m *mockErrManagedZonesCreateCall) Do(opts ...googleapi.CallOption) (*dns.ManagedZone, error) {
-	return nil, fmt.Errorf("failed")
 }
 
-type mockManagedZonesDeleteCall struct{}
-
-func (m *mockManagedZonesDeleteCall) Do(opts ...googleapi.CallOption) error {
-	return nil
-}
-
-type mockErrManagedZonesDeleteCall struct{}
-
-func (m *mockErrManagedZonesDeleteCall) Do(opts ...googleapi.CallOption) error {
-	return fmt.Errorf("failed")
-}
-
-type mockManagedZonesListCall struct{}
-
 func (m *mockManagedZonesListCall) Pages(ctx context.Context, f func(*dns.ManagedZonesListResponse) error) error {
-	return f(&dns.ManagedZonesListResponse{ManagedZones: expectedZones})
+	zones := []*dns.ManagedZone{}
-}
 
-type mockErrManagedZonesListCall struct{}
+	for k, v := range testZones {
+		if strings.HasPrefix(k, m.project+"/") {
+			zones = append(zones, v)
+		}
+	}
 
-func (m *mockErrManagedZonesListCall) Pages(ctx context.Context, f func(*dns.ManagedZonesListResponse) error) error {
+	return f(&dns.ManagedZonesListResponse{ManagedZones: zones})
-	return fmt.Errorf("failed")
 }
 
 type mockManagedZonesClient struct{}
 
-func (m *mockManagedZonesClient) Create(project string, managedzone *dns.ManagedZone) managedZonesCreateCallInterface {
+func (m *mockManagedZonesClient) Create(project string, managedZone *dns.ManagedZone) managedZonesCreateCallInterface {
-	return &mockManagedZonesCreateCall{}
+	return &mockManagedZonesCreateCall{project: project, managedZone: managedZone}
-}
-
-func (m *mockManagedZonesClient) Delete(project string, managedZone string) managedZonesDeleteCallInterface {
-	return &mockManagedZonesDeleteCall{}
 }
 
 func (m *mockManagedZonesClient) List(project string) managedZonesListCallInterface {
-	return &mockManagedZonesListCall{}
+	return &mockManagedZonesListCall{project: project}
 }
 
-type mockErrManagedZonesClient struct{}
+type mockResourceRecordSetsListCall struct {
-
+	project     string
-func (m *mockErrManagedZonesClient) Create(project string, managedzone *dns.ManagedZone) managedZonesCreateCallInterface {
+	managedZone string
-	return &mockErrManagedZonesCreateCall{}
 }
 
-func (m *mockErrManagedZonesClient) Delete(project string, managedZone string) managedZonesDeleteCallInterface {
-	return &mockErrManagedZonesDeleteCall{}
-}
-
-func (m *mockErrManagedZonesClient) List(project string) managedZonesListCallInterface {
-	return &mockErrManagedZonesListCall{}
-}
-
-type mockResourceRecordSetsListCall struct{}
-
 func (m *mockResourceRecordSetsListCall) Pages(ctx context.Context, f func(*dns.ResourceRecordSetsListResponse) error) error {
-	return f(&dns.ResourceRecordSetsListResponse{Rrsets: expectedRecordSets})
+	zoneKey := zoneKey(m.project, m.managedZone)
-}
 
-type mockErrResourceRecordSetsListCall struct{}
+	if _, ok := testZones[zoneKey]; !ok {
+		return &googleapi.Error{Code: http.StatusNotFound}
+	}
 
-func (m *mockErrResourceRecordSetsListCall) Pages(ctx context.Context, f func(*dns.ResourceRecordSetsListResponse) error) error {
+	resp := []*dns.ResourceRecordSet{}
-	return fmt.Errorf("failed")
+
+	for _, v := range testRecords[zoneKey] {
+		resp = append(resp, v)
+	}
+
+	return f(&dns.ResourceRecordSetsListResponse{Rrsets: resp})
 }
 
 type mockResourceRecordSetsClient struct{}
 
 func (m *mockResourceRecordSetsClient) List(project string, managedZone string) resourceRecordSetsListCallInterface {
-	return &mockResourceRecordSetsListCall{}
+	return &mockResourceRecordSetsListCall{project: project, managedZone: managedZone}
 }
 
-type mockErrResourceRecordSetsClient struct{}
+type mockChangesCreateCall struct {
-
+	project     string
-func (m *mockErrResourceRecordSetsClient) List(project string, managedZone string) resourceRecordSetsListCallInterface {
+	managedZone string
-	return &mockErrResourceRecordSetsListCall{}
+	change      *dns.Change
 }
 
-type mockChangesCreateCall struct{}
-
 func (m *mockChangesCreateCall) Do(opts ...googleapi.CallOption) (*dns.Change, error) {
-	return nil, nil
+	zoneKey := zoneKey(m.project, m.managedZone)
-}
 
-type mockErrChangesCreateCall struct{}
+	if _, ok := testZones[zoneKey]; !ok {
+		return nil, &googleapi.Error{Code: http.StatusNotFound}
+	}
 
-func (m *mockErrChangesCreateCall) Do(opts ...googleapi.CallOption) (*dns.Change, error) {
+	if _, ok := testRecords[zoneKey]; !ok {
-	return nil, fmt.Errorf("failed")
+		testRecords[zoneKey] = make(map[string]*dns.ResourceRecordSet)
+	}
+
+	for _, c := range append(m.change.Additions, m.change.Deletions...) {
+		if !isValidRecordSet(c) {
+			return nil, &googleapi.Error{
+				Code:    http.StatusBadRequest,
+				Message: fmt.Sprintf("invalid record: %v", c),
+			}
+		}
+	}
+
+	for _, del := range m.change.Deletions {
+		recordKey := recordKey(del.Type, del.Name)
+		delete(testRecords[zoneKey], recordKey)
+	}
+
+	for _, add := range m.change.Additions {
+		recordKey := recordKey(add.Type, add.Name)
+		testRecords[zoneKey][recordKey] = add
+	}
+
+	return m.change, nil
 }
 
 type mockChangesClient struct{}
 
 func (m *mockChangesClient) Create(project string, managedZone string, change *dns.Change) changesCreateCallInterface {
-	return &mockChangesCreateCall{}
+	return &mockChangesCreateCall{project: project, managedZone: managedZone, change: change}
 }
 
-type mockErrChangesClient struct{}
+func zoneKey(project, zoneName string) string {
+	return project + "/" + zoneName
+}
 
-func (m *mockErrChangesClient) Create(project string, managedZone string, change *dns.Change) changesCreateCallInterface {
+func recordKey(recordType, recordName string) string {
-	return &mockErrChangesCreateCall{}
+	return recordType + "/" + recordName
+}
+
+func isValidRecordSet(recordSet *dns.ResourceRecordSet) bool {
+	if !hasTrailingDot(recordSet.Name) {
+		return false
+	}
+
+	switch recordSet.Type {
+	case "CNAME":
+		for _, rrd := range recordSet.Rrdatas {
+			if !hasTrailingDot(rrd) {
+				return false
+			}
+		}
+	case "A", "TXT":
+		for _, rrd := range recordSet.Rrdatas {
+			if hasTrailingDot(rrd) {
+				return false
+			}
+		}
+	default:
+		panic("unhandled record type")
+	}
+
+	return true
+}
+
+func hasTrailingDot(target string) bool {
+	return strings.HasSuffix(target, ".")
 }
 
 func TestGoogleZones(t *testing.T) {
-	provider := &googleProvider{
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
-		project:            "project",
-		managedZonesClient: &mockManagedZonesClient{},
-	}
 
 	zones, err := provider.Zones()
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
 	}
 
-	if len(zones) != len(expectedZones) {
+	validateZones(t, zones, map[string]*dns.ManagedZone{
-		t.Errorf("expected %d zones, got %d", len(expectedZones), len(zones))
+		"zone-1-ext-dns-test-2-gcp-zalan-do": {Name: "zone-1-ext-dns-test-2-gcp-zalan-do", DnsName: "zone-1.ext-dns-test-2.gcp.zalan.do."},
-	}
+		"zone-2-ext-dns-test-2-gcp-zalan-do": {Name: "zone-2-ext-dns-test-2-gcp-zalan-do", DnsName: "zone-2.ext-dns-test-2.gcp.zalan.do."},
-
+		"zone-3-ext-dns-test-2-gcp-zalan-do": {Name: "zone-3-ext-dns-test-2-gcp-zalan-do", DnsName: "zone-3.ext-dns-test-2.gcp.zalan.do."},
-	provider.managedZonesClient = &mockErrManagedZonesClient{}
+	})
-
-	_, err = provider.Zones()
-	if err == nil {
-		t.Errorf("expected error")
-	}
-}
-
-func TestGoogleCreateZone(t *testing.T) {
-	provider := &googleProvider{
-		project:            "project",
-		managedZonesClient: &mockManagedZonesClient{},
-	}
-
-	err := provider.CreateZone("name", "domain")
-	if err != nil {
-		t.Errorf("should not fail: %s", err)
-	}
-
-	provider.managedZonesClient = &mockErrManagedZonesClient{}
-
-	err = provider.CreateZone("name", "domain")
-	if err == nil {
-		t.Errorf("expected error")
-	}
-}
-
-func TestGoogleDeleteZone(t *testing.T) {
-	provider := &googleProvider{
-		project:            "project",
-		managedZonesClient: &mockManagedZonesClient{},
-	}
-
-	err := provider.DeleteZone("name")
-	if err != nil {
-		t.Errorf("should not fail: %s", err)
-	}
-
-	provider.managedZonesClient = &mockErrManagedZonesClient{}
-
-	err = provider.DeleteZone("name")
-	if err == nil {
-		t.Errorf("expected error")
-	}
 }
 
 func TestGoogleRecords(t *testing.T) {
-	provider := &googleProvider{
+	originalEndpoints := []*endpoint.Endpoint{
-		project:                  "project",
+		endpoint.NewEndpoint("list-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
-		resourceRecordSetsClient: &mockResourceRecordSetsClient{},
+		endpoint.NewEndpoint("list-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("list-test-alias.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
 	}
 
-	endpoints, err := provider.Records("zone")
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, originalEndpoints)
+
+	records, err := provider.Records("_")
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
 	}
 
-	if len(endpoints) != len(expectedRecordSets)-1 {
+	validateEndpoints(t, records, originalEndpoints)
-		t.Errorf("expected %d endpoints, got %d", len(expectedRecordSets)-1, len(endpoints))
-	}
-
-	provider.resourceRecordSetsClient = &mockErrResourceRecordSetsClient{}
-
-	_, err = provider.Records("zone")
-	if err == nil {
-		t.Errorf("expected error")
-	}
 }
 
 func TestGoogleCreateRecords(t *testing.T) {
-	provider := &googleProvider{
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
-		project:       "project",
+
-		changesClient: &mockChangesClient{},
+	records := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", ""),
+		endpoint.NewEndpoint("create-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", ""),
+		endpoint.NewEndpoint("create-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", ""),
 	}
 
-	endpoints := []*endpoint.Endpoint{
+	if err := provider.CreateRecords(records); err != nil {
-		{
+		t.Fatal(err)
-			DNSName: "dns-name",
-			Target:  "target",
-		},
 	}
 
-	err := provider.CreateRecords("zone", endpoints)
+	records, err := provider.Records("_")
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
 	}
 
-	provider.changesClient = &mockErrChangesClient{}
+	validateEndpoints(t, records, []*endpoint.Endpoint{
-
+		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
-	err = provider.CreateRecords("zone", endpoints)
+		endpoint.NewEndpoint("create-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
-	if err == nil {
+		endpoint.NewEndpoint("create-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
-		t.Errorf("expected error")
+	})
-	}
 }
 
 func TestGoogleUpdateRecords(t *testing.T) {
-	provider := &googleProvider{
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{
-		project:       "project",
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
-		changesClient: &mockChangesClient{},
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
+	})
+
+	currentRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
+	}
+	updatedRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "4.3.2.1", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
 	}
 
-	records := []*endpoint.Endpoint{
+	if err := provider.UpdateRecords(updatedRecords, currentRecords); err != nil {
-		{
+		t.Fatal(err)
-			DNSName: "dns-name",
-			Target:  "target",
-		},
 	}
 
-	oldRecords := []*endpoint.Endpoint{
+	records, err := provider.Records("_")
-		{
-			DNSName: "dns-name",
-			Target:  "target",
-		},
-	}
-
-	err := provider.UpdateRecords("zone", records, oldRecords)
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
 	}
 
-	err = provider.UpdateRecords("zone", nil, nil)
+	validateEndpoints(t, records, []*endpoint.Endpoint{
-	if err != nil {
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
-		t.Errorf("should not fail: %s", err)
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "4.3.2.1", "A"),
-	}
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
-
+	})
-	provider.dryRun = true
-
-	err = provider.UpdateRecords("zone", records, oldRecords)
-	if err != nil {
-		t.Errorf("should not fail: %s", err)
-	}
 }
 
 func TestGoogleDeleteRecords(t *testing.T) {
-	provider := &googleProvider{
+	originalEndpoints := []*endpoint.Endpoint{
-		project:       "project",
+		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
-		changesClient: &mockChangesClient{},
+		endpoint.NewEndpoint("delete-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "baz.elb.amazonaws.com", "CNAME"),
 	}
 
-	endpoints := []*endpoint.Endpoint{
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, originalEndpoints)
-		{
+
-			DNSName: "dns-name",
+	if err := provider.DeleteRecords(originalEndpoints); err != nil {
-			Target:  "target",
+		t.Fatal(err)
-		},
 	}
 
-	err := provider.DeleteRecords("zone", endpoints)
+	records, err := provider.Records("_")
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
 	}
+
+	validateEndpoints(t, records, []*endpoint.Endpoint{})
 }
 
 func TestGoogleApplyChanges(t *testing.T) {
-	provider := &googleProvider{
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{
-		project:       "project",
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
-		changesClient: &mockChangesClient{},
+		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("delete-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
+		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "qux.elb.amazonaws.com", "CNAME"),
+	})
+
+	createRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("create-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("create-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
 	}
 
-	changes := &plan.Changes{}
+	currentRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
+	}
+	updatedRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "4.3.2.1", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "baz.elb.amazonaws.com", "CNAME"),
+	}
 
-	err := provider.ApplyChanges("zone", changes)
+	deleteRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("delete-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "qux.elb.amazonaws.com", "CNAME"),
+	}
+
+	changes := &plan.Changes{
+		Create:    createRecords,
+		UpdateNew: updatedRecords,
+		UpdateOld: currentRecords,
+		Delete:    deleteRecords,
+	}
+
+	if err := provider.ApplyChanges("_", changes); err != nil {
+		t.Fatal(err)
+	}
+
+	records, err := provider.Records("_")
 	if err != nil {
-		t.Errorf("should not fail: %s", err)
+		t.Fatal(err)
+	}
+
+	validateEndpoints(t, records, []*endpoint.Endpoint{
+		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
+		endpoint.NewEndpoint("create-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "4.3.2.1", "A"),
+		endpoint.NewEndpoint("create-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "baz.elb.amazonaws.com", "CNAME"),
+	})
+}
+
+func TestGoogleApplyChangesDryRun(t *testing.T) {
+	originalEndpoints := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("delete-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
+		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "qux.elb.amazonaws.com", "CNAME"),
+	}
+
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", true, originalEndpoints)
+
+	createRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("create-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("create-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
+	}
+
+	currentRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "bar.elb.amazonaws.com", "CNAME"),
+	}
+	updatedRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", "A"),
+		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.gcp.zalan.do", "4.3.2.1", "A"),
+		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "baz.elb.amazonaws.com", "CNAME"),
+	}
+
+	deleteRecords := []*endpoint.Endpoint{
+		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.gcp.zalan.do", "8.8.8.8", "A"),
+		endpoint.NewEndpoint("delete-test.zone-2.ext-dns-test-2.gcp.zalan.do", "8.8.4.4", "A"),
+		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "qux.elb.amazonaws.com", "CNAME"),
+	}
+
+	changes := &plan.Changes{
+		Create:    createRecords,
+		UpdateNew: updatedRecords,
+		UpdateOld: currentRecords,
+		Delete:    deleteRecords,
+	}
+
+	if err := provider.ApplyChanges("_", changes); err != nil {
+		t.Fatal(err)
+	}
+
+	records, err := provider.Records("_")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	validateEndpoints(t, records, originalEndpoints)
+}
+
+func TestGoogleApplyChangesEmpty(t *testing.T) {
+	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
+
+	if err := provider.ApplyChanges("_", &plan.Changes{}); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestSeparateChanges(t *testing.T) {
+	change := &dns.Change{
+		Additions: []*dns.ResourceRecordSet{
+			{Name: "qux.foo.example.org.", Ttl: 1},
+			{Name: "qux.bar.example.org.", Ttl: 2},
+		},
+		Deletions: []*dns.ResourceRecordSet{
+			{Name: "wambo.foo.example.org.", Ttl: 10},
+			{Name: "wambo.bar.example.org.", Ttl: 20},
+		},
+	}
+
+	zones := map[string]*dns.ManagedZone{
+		"foo-example-org": {
+			Name:    "foo-example-org",
+			DnsName: "foo.example.org.",
+		},
+		"bar-example-org": {
+			Name:    "bar-example-org",
+			DnsName: "bar.example.org.",
+		},
+		"baz-example-org": {
+			Name:    "baz-example-org",
+			DnsName: "baz.example.org.",
+		},
+	}
+
+	changes := separateChange(zones, change)
+
+	if len(changes) != 2 {
+		t.Fatalf("expected %d change(s), got %d", 2, len(changes))
+	}
+
+	validateChange(t, changes["foo-example-org"], &dns.Change{
+		Additions: []*dns.ResourceRecordSet{
+			{Name: "qux.foo.example.org.", Ttl: 1},
+		},
+		Deletions: []*dns.ResourceRecordSet{
+			{Name: "wambo.foo.example.org.", Ttl: 10},
+		},
+	})
+
+	validateChange(t, changes["bar-example-org"], &dns.Change{
+		Additions: []*dns.ResourceRecordSet{
+			{Name: "qux.bar.example.org.", Ttl: 2},
+		},
+		Deletions: []*dns.ResourceRecordSet{
+			{Name: "wambo.bar.example.org.", Ttl: 20},
+		},
+	})
+}
+
+func TestGoogleSuitableZone(t *testing.T) {
+	zones := map[string]*dns.ManagedZone{
+		"example-org":     {Name: "example-org", DnsName: "example.org."},
+		"bar-example-org": {Name: "bar-example-org", DnsName: "bar.example.org."},
+	}
+
+	for _, tc := range []struct {
+		hostname string
+		expected *dns.ManagedZone
+	}{
+		{"foo.bar.example.org.", zones["bar-example-org"]},
+		{"foo.example.org.", zones["example-org"]},
+		{"foo.kubernetes.io.", nil},
+	} {
+		suitableZone := suitableManagedZone(tc.hostname, zones)
+
+		if suitableZone != tc.expected {
+			t.Errorf("expected %v, got %v", tc.expected, suitableZone)
+		}
+	}
+}
+
+func validateZones(t *testing.T, zones map[string]*dns.ManagedZone, expected map[string]*dns.ManagedZone) {
+	if len(zones) != len(expected) {
+		t.Fatalf("expected %d zone(s), got %d", len(expected), len(zones))
+	}
+
+	for i, zone := range zones {
+		validateZone(t, zone, expected[i])
+	}
+}
+
+func validateZone(t *testing.T, zone *dns.ManagedZone, expected *dns.ManagedZone) {
+	if zone.Name != expected.Name {
+		t.Errorf("expected %s, got %s", expected.Name, zone.Name)
+	}
+
+	if zone.DnsName != expected.DnsName {
+		t.Errorf("expected %s, got %s", expected.DnsName, zone.DnsName)
+	}
+}
+
+func validateChange(t *testing.T, change *dns.Change, expected *dns.Change) {
+	validateChangeRecords(t, change.Additions, expected.Additions)
+	validateChangeRecords(t, change.Deletions, expected.Deletions)
+}
+
+func validateChangeRecords(t *testing.T, records []*dns.ResourceRecordSet, expected []*dns.ResourceRecordSet) {
+	if len(records) != len(expected) {
+		t.Fatalf("expected %d change(s), got %d", len(expected), len(records))
+	}
+
+	for i := range records {
+		validateChangeRecord(t, records[i], expected[i])
+	}
+}
+
+func validateChangeRecord(t *testing.T, record *dns.ResourceRecordSet, expected *dns.ResourceRecordSet) {
+	if record.Name != expected.Name {
+		t.Errorf("expected %s, got %s", expected.Name, record.Name)
+	}
+
+	if record.Ttl != expected.Ttl {
+		t.Errorf("expected %d, got %d", expected.Ttl, record.Ttl)
+	}
+}
+
+func newGoogleProvider(t *testing.T, domain string, dryRun bool, records []*endpoint.Endpoint) *googleProvider {
+	provider := &googleProvider{
+		project: "zalando-external-dns-test",
+		domain:  domain,
+		dryRun:  false,
+		resourceRecordSetsClient: &mockResourceRecordSetsClient{},
+		managedZonesClient:       &mockManagedZonesClient{},
+		changesClient:            &mockChangesClient{},
+	}
+
+	createZone(t, provider, &dns.ManagedZone{
+		Name:    "zone-1-ext-dns-test-2-gcp-zalan-do",
+		DnsName: "zone-1.ext-dns-test-2.gcp.zalan.do.",
+	})
+
+	createZone(t, provider, &dns.ManagedZone{
+		Name:    "zone-2-ext-dns-test-2-gcp-zalan-do",
+		DnsName: "zone-2.ext-dns-test-2.gcp.zalan.do.",
+	})
+
+	createZone(t, provider, &dns.ManagedZone{
+		Name:    "zone-3-ext-dns-test-2-gcp-zalan-do",
+		DnsName: "zone-3.ext-dns-test-2.gcp.zalan.do.",
+	})
+
+	setupGoogleRecords(t, provider, records)
+
+	provider.dryRun = dryRun
+
+	return provider
+}
+
+func createZone(t *testing.T, provider *googleProvider, zone *dns.ManagedZone) {
+	zone.Description = "Testing zone for kubernetes.io/external-dns"
+
+	if _, err := provider.managedZonesClient.Create("zalando-external-dns-test", zone).Do(); err != nil {
+		if err, ok := err.(*googleapi.Error); !ok || err.Code != http.StatusConflict {
+			t.Fatal(err)
+		}
+	}
+}
+
+func setupGoogleRecords(t *testing.T, provider *googleProvider, endpoints []*endpoint.Endpoint) {
+	clearGoogleRecords(t, provider, "zone-1-ext-dns-test-2-gcp-zalan-do")
+	clearGoogleRecords(t, provider, "zone-2-ext-dns-test-2-gcp-zalan-do")
+
+	records, err := provider.Records("_")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	validateEndpoints(t, records, []*endpoint.Endpoint{})
+
+	if err = provider.CreateRecords(endpoints); err != nil {
+		t.Fatal(err)
+	}
+
+	records, err = provider.Records("_")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	validateEndpoints(t, records, endpoints)
+}
+
+func clearGoogleRecords(t *testing.T, provider *googleProvider, zone string) {
+	recordSets := []*dns.ResourceRecordSet{}
+	if err := provider.resourceRecordSetsClient.List(provider.project, zone).Pages(context.TODO(), func(resp *dns.ResourceRecordSetsListResponse) error {
+		for _, r := range resp.Rrsets {
+			switch r.Type {
+			case "A", "CNAME":
+				recordSets = append(recordSets, r)
+			}
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	if len(recordSets) != 0 {
+		if _, err := provider.changesClient.Create(provider.project, zone, &dns.Change{
+			Deletions: recordSets,
+		}).Do(); err != nil {
+			t.Fatal(err)
+		}
 	}
 }

provider/provider.go

@@ -18,6 +18,7 @@ package provider
 
 import (
 	"net"
+	"strings"
 
 	"github.com/kubernetes-incubator/external-dns/endpoint"
 	"github.com/kubernetes-incubator/external-dns/plan"
@@ -40,3 +41,12 @@ func suitableType(ep *endpoint.Endpoint) string {
 	}
 	return "CNAME"
 }
+
+// ensureTrailingDot ensures that the hostname receives a trailing dot if it hasn't already.
+func ensureTrailingDot(hostname string) string {
+	if net.ParseIP(hostname) != nil {
+		return hostname
+	}
+
+	return strings.TrimSuffix(hostname, ".") + "."
+}

provider/provider_test.go

@@ -43,3 +43,19 @@ func TestSuitableType(t *testing.T) {
 		}
 	}
 }
+
+func TestEnsureTrailingDot(t *testing.T) {
+	for _, tc := range []struct {
+		input, expected string
+	}{
+		{"example.org", "example.org."},
+		{"example.org.", "example.org."},
+		{"8.8.8.8", "8.8.8.8"},
+	} {
+		output := ensureTrailingDot(tc.input)
+
+		if output != tc.expected {
+			t.Errorf("expected %s, got %s", tc.expected, output)
+		}
+	}
+}