Support for multiple domains within --domain-filter (#252)

* Support for multiple domains within --domain-filter

The parameter accepts a comma separated list of domains with or without trailing dot. Example: --domain-filter="example.org, company.test.,staging.com". Closes #247 and #229

* Add boilerplate header

* Add documentation for methods and structs

* use StringsVar for the domain-filter flag

* go fmt

* Remove camel case from tests

* Revert changes in README.md

* Move DomainFilter to provider package

* Make a new slice and copy elements to it

* Update CHANGELOG.md

* docs: change minor spelling mistake

CHANGELOG.md

@@ -1,3 +1,6 @@
+  - The flag `--domain-filter` can be repeated multiple times like `--domain-filter=example.com --domain-filter=company.org.`.
+  - A trailing period is not required anymore for `--domain-filter` when AWS (or any other) provider is used.
+
 ## v0.3.0 - 2017-05-08
 
 Features:

docs/tutorials/aws.md

@@ -84,7 +84,7 @@ spec:
         args:
         - --source=service
         - --source=ingress
-        - --domain-filter=external-dns-test.my-org.com. # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
+        - --domain-filter=external-dns-test.my-org.com # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
         - --provider=aws
         - --policy=upsert-only # would prevent ExternalDNS from deleting any records, omit to enable full synchronization
         - --registry=txt

docs/tutorials/gke.md

@@ -81,7 +81,7 @@ spec:
         args:
         - --source=service
         - --source=ingress
-        - --domain-filter=external-dns-test.gcp.zalan.do. #will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
+        - --domain-filter=external-dns-test.gcp.zalan.do # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
         - --provider=google
         - --google-project=zalando-external-dns-test
         - --policy=upsert-only # would prevent ExternalDNS from deleting any records, omit to enable full synchronization

docs/tutorials/nginx-ingress.md

@@ -220,7 +220,7 @@ spec:
         image: registry.opensource.zalan.do/teapot/external-dns:v0.3.0
         args:
         - --source=ingress
-        - --domain-filter=external-dns-test.gcp.zalan.do.
+        - --domain-filter=external-dns-test.gcp.zalan.do
         - --provider=google
         - --google-project=zalando-external-dns-test
         - --registry=txt

main.go

@@ -108,20 +108,22 @@ func main() {
 
 	endpointsSource := source.NewDedupSource(source.NewMultiSource(sources))
 
+	domainFilter := provider.NewDomainFilter(cfg.DomainFilter)
+
 	var p provider.Provider
 	switch cfg.Provider {
 	case "aws":
-		p, err = provider.NewAWSProvider(cfg.DomainFilter, cfg.DryRun)
+		p, err = provider.NewAWSProvider(domainFilter, cfg.DryRun)
 	case "azure":
-		p, err = provider.NewAzureProvider(cfg.AzureConfigFile, cfg.DomainFilter, cfg.AzureResourceGroup, cfg.DryRun)
+		p, err = provider.NewAzureProvider(cfg.AzureConfigFile, domainFilter, cfg.AzureResourceGroup, cfg.DryRun)
 	case "cloudflare":
-		p, err = provider.NewCloudFlareProvider(cfg.DomainFilter, cfg.DryRun)
+		p, err = provider.NewCloudFlareProvider(domainFilter, cfg.DryRun)
 	case "google":
-		p, err = provider.NewGoogleProvider(cfg.GoogleProject, cfg.DomainFilter, cfg.DryRun)
+		p, err = provider.NewGoogleProvider(cfg.GoogleProject, domainFilter, cfg.DryRun)
 	case "digitalocean":
-		p, err = provider.NewDigitalOceanProvider(cfg.DomainFilter, cfg.DryRun)
+		p, err = provider.NewDigitalOceanProvider(domainFilter, cfg.DryRun)
 	case "inmemory":
-		p, err = provider.NewInMemoryProvider(provider.InMemoryWithDomain(cfg.DomainFilter), provider.InMemoryWithLogging()), nil
+		p, err = provider.NewInMemoryProvider(provider.InMemoryWithDomain(domainFilter), provider.InMemoryWithLogging()), nil
 	default:
 		log.Fatalf("unknown dns provider: %s", cfg.Provider)
 	}

pkg/apis/externaldns/types.go

@@ -36,7 +36,7 @@ type Config struct {
 	Compatibility      string
 	Provider           string
 	GoogleProject      string
-	DomainFilter       string
+	DomainFilter       []string
 	AzureConfigFile    string
 	AzureResourceGroup string
 	Policy             string
@@ -60,7 +60,7 @@ var defaultConfig = &Config{
 	Compatibility:      "",
 	Provider:           "",
 	GoogleProject:      "",
-	DomainFilter:       "",
+	DomainFilter:       []string{},
 	AzureConfigFile:    "/etc/kubernetes/azure.json",
 	AzureResourceGroup: "",
 	Policy:             "sync",
@@ -99,7 +99,7 @@ func (cfg *Config) ParseFlags(args []string) error {
 	// Flags related to providers
 	app.Flag("provider", "The DNS provider where the DNS records will be created (required, options: aws, google, azure, cloudflare, digitalocean, inmemory)").Required().PlaceHolder("provider").EnumVar(&cfg.Provider, "aws", "google", "azure", "cloudflare", "digitalocean", "inmemory")
 	app.Flag("google-project", "When using the Google provider, specify the Google project (required when --provider=google)").Default(defaultConfig.GoogleProject).StringVar(&cfg.GoogleProject)
-	app.Flag("domain-filter", "Limit possible target zones by a domain suffix (optional)").Default(defaultConfig.DomainFilter).StringVar(&cfg.DomainFilter)
+	app.Flag("domain-filter", "Limit possible target zones by a domain suffix; specify multiple times for multiple domains (optional)").Default("").StringsVar(&cfg.DomainFilter)
 	app.Flag("azure-config-file", "When using the Azure provider, specify the Azure configuration file (required when --provider=azure").Default(defaultConfig.AzureConfigFile).StringVar(&cfg.AzureConfigFile)
 	app.Flag("azure-resource-group", "When using the Azure provider, override the Azure resource group to use (optional)").Default(defaultConfig.AzureResourceGroup).StringVar(&cfg.AzureResourceGroup)
 

pkg/apis/externaldns/types_test.go

@@ -35,7 +35,7 @@ var (
 		Compatibility:      "",
 		Provider:           "google",
 		GoogleProject:      "",
-		DomainFilter:       "",
+		DomainFilter:       []string{""},
 		AzureConfigFile:    "/etc/kubernetes/azure.json",
 		AzureResourceGroup: "",
 		Policy:             "sync",
@@ -59,7 +59,7 @@ var (
 		Compatibility:      "mate",
 		Provider:           "google",
 		GoogleProject:      "project",
-		DomainFilter:       "example.org.",
+		DomainFilter:       []string{"example.org", "company.com"},
 		AzureConfigFile:    "azure.json",
 		AzureResourceGroup: "arg",
 		Policy:             "upsert-only",
@@ -105,7 +105,8 @@ func TestParseFlags(t *testing.T) {
 				"--google-project=project",
 				"--azure-config-file=azure.json",
 				"--azure-resource-group=arg",
-				"--domain-filter=example.org.",
+				"--domain-filter=example.org",
+				"--domain-filter=company.com",
 				"--policy=upsert-only",
 				"--registry=noop",
 				"--txt-owner-id=owner-1",
@@ -134,7 +135,7 @@ func TestParseFlags(t *testing.T) {
 				"EXTERNAL_DNS_GOOGLE_PROJECT":       "project",
 				"EXTERNAL_DNS_AZURE_CONFIG_FILE":    "azure.json",
 				"EXTERNAL_DNS_AZURE_RESOURCE_GROUP": "arg",
-				"EXTERNAL_DNS_DOMAIN_FILTER":        "example.org.",
+				"EXTERNAL_DNS_DOMAIN_FILTER":        "example.org\ncompany.com",
 				"EXTERNAL_DNS_POLICY":               "upsert-only",
 				"EXTERNAL_DNS_REGISTRY":             "noop",
 				"EXTERNAL_DNS_TXT_OWNER_ID":         "owner-1",

provider/aws.go

@@ -70,11 +70,11 @@ type AWSProvider struct {
 	client Route53API
 	dryRun bool
 	// only consider hosted zones managing domains ending in this suffix
-	domainFilter string
+	domainFilter DomainFilter
 }
 
 // NewAWSProvider initializes a new AWS Route53 based Provider.
-func NewAWSProvider(domainFilter string, dryRun bool) (*AWSProvider, error) {
+func NewAWSProvider(domainFilter DomainFilter, dryRun bool) (*AWSProvider, error) {
 	config := aws.NewConfig()
 
 	config = config.WithHTTPClient(
@@ -109,7 +109,7 @@ func (p *AWSProvider) Zones() (map[string]*route53.HostedZone, error) {
 
 	f := func(resp *route53.ListHostedZonesOutput, lastPage bool) (shouldContinue bool) {
 		for _, zone := range resp.HostedZones {
-			if strings.HasSuffix(aws.StringValue(zone.Name), p.domainFilter) {
+			if p.domainFilter.Match(aws.StringValue(zone.Name)) {
 				zones[aws.StringValue(zone.Id)] = zone
 			}
 		}

provider/aws_test.go

@@ -23,7 +23,6 @@ import (
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/route53"
-
 	"github.com/kubernetes-incubator/external-dns/endpoint"
 	"github.com/kubernetes-incubator/external-dns/internal/testutils"
 	"github.com/kubernetes-incubator/external-dns/plan"
@@ -145,7 +144,7 @@ func (r *Route53APIStub) CreateHostedZone(input *route53.CreateHostedZoneInput)
 }
 
 func TestAWSZones(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	zones, err := provider.Zones()
 	require.NoError(t, err)
@@ -167,7 +166,7 @@ func TestAWSZones(t *testing.T) {
 }
 
 func TestAWSRecords(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{
 		endpoint.NewEndpoint("list-test.zone-1.ext-dns-test-2.teapot.zalan.do", "1.2.3.4", "A"),
 		endpoint.NewEndpoint("list-test.zone-2.ext-dns-test-2.teapot.zalan.do", "8.8.8.8", "A"),
 		endpoint.NewEndpoint("list-test-alias.zone-1.ext-dns-test-2.teapot.zalan.do", "foo.eu-central-1.elb.amazonaws.com", "ALIAS"),
@@ -184,7 +183,7 @@ func TestAWSRecords(t *testing.T) {
 }
 
 func TestAWSCreateRecords(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	records := []*endpoint.Endpoint{
 		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.teapot.zalan.do", "1.2.3.4", ""),
@@ -205,7 +204,7 @@ func TestAWSCreateRecords(t *testing.T) {
 }
 
 func TestAWSUpdateRecords(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{
 		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.teapot.zalan.do", "8.8.8.8", "A"),
 		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.teapot.zalan.do", "8.8.4.4", "A"),
 		endpoint.NewEndpoint("update-test-cname.zone-1.ext-dns-test-2.teapot.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
@@ -243,7 +242,7 @@ func TestAWSDeleteRecords(t *testing.T) {
 		endpoint.NewEndpoint("delete-test-cname-alias.zone-1.ext-dns-test-2.teapot.zalan.do", "foo.eu-central-1.elb.amazonaws.com", "CNAME"),
 	}
 
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, originalEndpoints)
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, originalEndpoints)
 
 	require.NoError(t, provider.DeleteRecords(originalEndpoints))
 
@@ -254,7 +253,7 @@ func TestAWSDeleteRecords(t *testing.T) {
 }
 
 func TestAWSApplyChanges(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{
 		endpoint.NewEndpoint("update-test.zone-1.ext-dns-test-2.teapot.zalan.do", "8.8.8.8", "A"),
 		endpoint.NewEndpoint("delete-test.zone-1.ext-dns-test-2.teapot.zalan.do", "8.8.8.8", "A"),
 		endpoint.NewEndpoint("update-test.zone-2.ext-dns-test-2.teapot.zalan.do", "8.8.4.4", "A"),
@@ -328,7 +327,7 @@ func TestAWSApplyChangesDryRun(t *testing.T) {
 		endpoint.NewEndpoint("delete-test-cname-alias.zone-1.ext-dns-test-2.teapot.zalan.do", "qux.elb.amazonaws.com", "ALIAS"),
 	}
 
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", true, originalEndpoints)
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), true, originalEndpoints)
 
 	createRecords := []*endpoint.Endpoint{
 		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.teapot.zalan.do", "8.8.8.8", ""),
@@ -480,7 +479,7 @@ func validateAWSChangeRecord(t *testing.T, record *route53.Change, expected *rou
 }
 
 func TestAWSCreateRecordsWithCNAME(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	records := []*endpoint.Endpoint{
 		{DNSName: "create-test.zone-1.ext-dns-test-2.teapot.zalan.do", Target: "foo.example.org"},
@@ -505,7 +504,7 @@ func TestAWSCreateRecordsWithCNAME(t *testing.T) {
 }
 
 func TestAWSCreateRecordsWithALIAS(t *testing.T) {
-	provider := newAWSProvider(t, "ext-dns-test-2.teapot.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newAWSProvider(t, NewDomainFilter([]string{"ext-dns-test-2.teapot.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	records := []*endpoint.Endpoint{
 		{DNSName: "create-test.zone-1.ext-dns-test-2.teapot.zalan.do", Target: "foo.eu-central-1.elb.amazonaws.com"},
@@ -662,7 +661,7 @@ func clearAWSRecords(t *testing.T, provider *AWSProvider, zone string) {
 	}
 }
 
-func newAWSProvider(t *testing.T, domainFilter string, dryRun bool, records []*endpoint.Endpoint) *AWSProvider {
+func newAWSProvider(t *testing.T, domainFilter DomainFilter, dryRun bool, records []*endpoint.Endpoint) *AWSProvider {
 	client := NewRoute53APIStub()
 
 	provider := &AWSProvider{

provider/azure.go

@@ -65,7 +65,7 @@ type RecordsClient interface {
 
 // AzureProvider implements the DNS provider for Microsoft's Azure cloud platform.
 type AzureProvider struct {
-	domainFilter  string
+	domainFilter  DomainFilter
 	dryRun        bool
 	resourceGroup string
 	zonesClient   ZonesClient
@@ -75,7 +75,7 @@ type AzureProvider struct {
 // NewAzureProvider creates a new Azure provider.
 //
 // Returns the provider or an error if a provider could not be created.
-func NewAzureProvider(configFile string, domainFilter string, resourceGroup string, dryRun bool) (*AzureProvider, error) {
+func NewAzureProvider(configFile string, domainFilter DomainFilter, resourceGroup string, dryRun bool) (*AzureProvider, error) {
 	contents, err := ioutil.ReadFile(configFile)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read Azure config file '%s': %v", configFile, err)
@@ -195,7 +195,7 @@ func (p *AzureProvider) zones() ([]dns.Zone, error) {
 
 	for list.Value != nil && len(*list.Value) > 0 {
 		for _, zone := range *list.Value {
-			if zone.Name != nil && strings.HasSuffix(*zone.Name, p.domainFilter) {
+			if zone.Name != nil && p.domainFilter.Match(*zone.Name) {
 				zones = append(zones, zone)
 			}
 		}

provider/azure_test.go

@@ -138,7 +138,7 @@ func (client *mockRecordsClient) CreateOrUpdate(resourceGroupName string, zoneNa
 	return parameters, nil
 }
 
-func newAzureProvider(domainFilter string, dryRun bool, resourceGroup string, zonesClient ZonesClient, recordsClient RecordsClient) *AzureProvider {
+func newAzureProvider(domainFilter DomainFilter, dryRun bool, resourceGroup string, zonesClient ZonesClient, recordsClient RecordsClient) *AzureProvider {
 	return &AzureProvider{
 		domainFilter:  domainFilter,
 		dryRun:        dryRun,
@@ -169,7 +169,7 @@ func TestAzureRecord(t *testing.T) {
 		},
 	}
 
-	provider := newAzureProvider("example.com", true, "k8s", &zonesClient, &recordsClient)
+	provider := newAzureProvider(NewDomainFilter([]string{"example.com"}), true, "k8s", &zonesClient, &recordsClient)
 	actual, err := provider.Records()
 
 	if err != nil {
@@ -224,7 +224,7 @@ func TestAzureApplyChangesDryRun(t *testing.T) {
 
 func testAzureApplyChangesInternal(t *testing.T, dryRun bool, client RecordsClient) {
 	provider := newAzureProvider(
-		"",
+		NewDomainFilter([]string{""}),
 		dryRun,
 		"group",
 		&mockZonesClient{

provider/cloudflare.go

@@ -83,7 +83,7 @@ func (z zoneService) DeleteDNSRecord(zoneID, recordID string) error {
 type CloudFlareProvider struct {
 	Client cloudFlareDNS
 	// only consider hosted zones managing domains ending in this suffix
-	domainFilter string
+	domainFilter DomainFilter
 	DryRun       bool
 }
 
@@ -94,7 +94,7 @@ type cloudFlareChange struct {
 }
 
 // NewCloudFlareProvider initializes a new CloudFlare DNS based Provider.
-func NewCloudFlareProvider(domainFilter string, dryRun bool) (*CloudFlareProvider, error) {
+func NewCloudFlareProvider(domainFilter DomainFilter, dryRun bool) (*CloudFlareProvider, error) {
 	// initialize via API email and API key and returns new API object
 	config, err := cloudflare.New(os.Getenv("CF_API_KEY"), os.Getenv("CF_API_EMAIL"))
 	if err != nil {
@@ -119,7 +119,7 @@ func (p *CloudFlareProvider) Zones() ([]cloudflare.Zone, error) {
 	}
 
 	for _, zone := range zones {
-		if strings.HasSuffix(zone.Name, p.domainFilter) {
+		if p.domainFilter.Match(zone.Name) {
 			result = append(result, zone)
 		}
 	}

provider/cloudflare_test.go

@@ -344,7 +344,7 @@ func TestNewCloudFlareChanges(t *testing.T) {
 func TestCloudFlareZones(t *testing.T) {
 	provider := &CloudFlareProvider{
 		Client:       &mockCloudFlareClient{},
-		domainFilter: "zalando.to.",
+		domainFilter: NewDomainFilter([]string{"zalando.to."}),
 	}
 
 	zones, err := provider.Zones()
@@ -382,13 +382,13 @@ func TestRecords(t *testing.T) {
 func TestNewCloudFlareProvider(t *testing.T) {
 	_ = os.Setenv("CF_API_KEY", "xxxxxxxxxxxxxxxxx")
 	_ = os.Setenv("CF_API_EMAIL", "test@test.com")
-	_, err := NewCloudFlareProvider("ext-dns-test.zalando.to.", true)
+	_, err := NewCloudFlareProvider(NewDomainFilter([]string{"ext-dns-test.zalando.to."}), true)
 	if err != nil {
 		t.Errorf("should not fail, %s", err)
 	}
 	_ = os.Unsetenv("CF_API_KEY")
 	_ = os.Unsetenv("CF_API_EMAIL")
-	_, err = NewCloudFlareProvider("ext-dns-test.zalando.to.", true)
+	_, err = NewCloudFlareProvider(NewDomainFilter([]string{"ext-dns-test.zalando.to."}), true)
 	if err == nil {
 		t.Errorf("expected to fail")
 	}

provider/digital_ocean.go

@@ -44,7 +44,7 @@ const (
 type DigitalOceanProvider struct {
 	Client godo.DomainsService
 	// only consider hosted zones managing domains ending in this suffix
-	domainFilter string
+	domainFilter DomainFilter
 	DryRun       bool
 }
 
@@ -55,7 +55,7 @@ type DigitalOceanChange struct {
 }
 
 // NewDigitalOceanProvider initializes a new DigitalOcean DNS based Provider.
-func NewDigitalOceanProvider(domainFilter string, dryRun bool) (*DigitalOceanProvider, error) {
+func NewDigitalOceanProvider(domainFilter DomainFilter, dryRun bool) (*DigitalOceanProvider, error) {
 	token, ok := os.LookupEnv("DO_TOKEN")
 	if !ok {
 		return nil, fmt.Errorf("No token found")
@@ -83,7 +83,7 @@ func (p *DigitalOceanProvider) Zones() ([]godo.Domain, error) {
 	}
 
 	for _, zone := range zones {
-		if strings.HasSuffix(zone.Name, p.domainFilter) {
+		if p.domainFilter.Match(zone.Name) {
 			result = append(result, zone)
 		}
 	}

provider/digital_ocean_test.go

@@ -393,7 +393,7 @@ func TestNewDigitalOceanChanges(t *testing.T) {
 func TestDigitalOceanZones(t *testing.T) {
 	provider := &DigitalOceanProvider{
 		Client:       &mockDigitalOceanClient{},
-		domainFilter: "com",
+		domainFilter: NewDomainFilter([]string{"com"}),
 	}
 
 	zones, err := provider.Zones()
@@ -442,12 +442,12 @@ func TestDigitalOceanApplyChanges(t *testing.T) {
 
 func TestNewDigitalOceanProvider(t *testing.T) {
 	_ = os.Setenv("DO_TOKEN", "xxxxxxxxxxxxxxxxx")
-	_, err := NewDigitalOceanProvider("ext-dns-test.zalando.to.", true)
+	_, err := NewDigitalOceanProvider(NewDomainFilter([]string{"ext-dns-test.zalando.to."}), true)
 	if err != nil {
 		t.Errorf("should not fail, %s", err)
 	}
 	_ = os.Unsetenv("DO_TOKEN")
-	_, err = NewDigitalOceanProvider("ext-dns-test.zalando.to.", true)
+	_, err = NewDigitalOceanProvider(NewDomainFilter([]string{"ext-dns-test.zalando.to."}), true)
 	if err == nil {
 		t.Errorf("expected to fail")
 	}

provider/domainfilter.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package provider
+
+import (
+	"strings"
+)
+
+// DomainFilter holds a lists of valid domain names
+type DomainFilter struct {
+	filters []string
+}
+
+// NewDomainFilter returns a new DomainFilter given a comma separated list of domains
+func NewDomainFilter(domainFilters []string) DomainFilter {
+	filters := make([]string, len(domainFilters))
+
+	// user can define filter domains either with trailing dot or without, we remove all trailing periods from
+	// the internal representation
+	for i, domain := range domainFilters {
+		filters[i] = strings.TrimSuffix(strings.TrimSpace(domain), ".")
+	}
+
+	return DomainFilter{filters}
+}
+
+// Match checks whether a domain can be found in the DomainFilter.
+func (df DomainFilter) Match(domain string) bool {
+	// return always true, if not filter is specified
+	if len(df.filters) == 0 {
+		return true
+	}
+
+	for _, filter := range df.filters {
+
+		if strings.HasSuffix(strings.TrimSuffix(domain, "."), filter) {
+			return true
+		}
+	}
+
+	return false
+}

provider/domainfilter_test.go

@@ -0,0 +1,122 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package provider
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type domainFilterTest struct {
+	domainFilter []string
+	domains      []string
+	expected     bool
+}
+
+var domainFilterTests = []domainFilterTest{
+	{
+		[]string{"google.com.", "exaring.de", "inovex.de"},
+		[]string{"google.com", "exaring.de", "inovex.de"},
+		true,
+	},
+	{
+		[]string{"google.com.", "exaring.de", "inovex.de"},
+		[]string{"google.com", "exaring.de", "inovex.de"},
+		true,
+	},
+	{
+		[]string{"google.com.", "exaring.de.", "inovex.de"},
+		[]string{"google.com", "exaring.de", "inovex.de"},
+		true,
+	},
+	{
+		[]string{"foo.org.      "},
+		[]string{"foo.org"},
+		true,
+	},
+	{
+		[]string{"   foo.org"},
+		[]string{"foo.org"},
+		true,
+	},
+	{
+		[]string{"foo.org."},
+		[]string{"foo.org"},
+		true,
+	},
+	{
+		[]string{"foo.org."},
+		[]string{"baz.org"},
+		false,
+	},
+	{
+		[]string{"baz.foo.org."},
+		[]string{"foo.org"},
+		false,
+	},
+	{
+		[]string{"", "foo.org."},
+		[]string{"foo.org"},
+		true,
+	},
+	{
+		[]string{"", "foo.org."},
+		[]string{},
+		true,
+	},
+	{
+		[]string{""},
+		[]string{"foo.org"},
+		true,
+	},
+	{
+		[]string{""},
+		[]string{},
+		true,
+	},
+	{
+		[]string{" "},
+		[]string{},
+		true,
+	},
+	{
+		[]string{"bar.sub.example.org"},
+		[]string{"foo.bar.sub.example.org"},
+		true,
+	},
+}
+
+func TestDomainFilterMatch(t *testing.T) {
+	for i, tt := range domainFilterTests {
+		domainFilter := NewDomainFilter(tt.domainFilter)
+		for _, domain := range tt.domains {
+			assert.Equal(t, tt.expected, domainFilter.Match(domain), "should not fail: %v in test-case #%v", domain, i)
+			assert.Equal(t, tt.expected, domainFilter.Match(domain+"."), "should not fail: %v in test-case #%v", domain+".", i)
+		}
+	}
+}
+
+func TestDomainFilterMatchWithEmptyFilter(t *testing.T) {
+	for _, tt := range domainFilterTests {
+		domainFilter := DomainFilter{}
+		for i, domain := range tt.domains {
+			assert.True(t, domainFilter.Match(domain), "should not fail: %v in test-case #%v", domain, i)
+			assert.True(t, domainFilter.Match(domain+"."), "should not fail: %v in test-case #%v", domain+".", i)
+		}
+	}
+}

provider/google.go

@@ -96,7 +96,7 @@ type GoogleProvider struct {
 	// Enabled dry-run will print any modifying actions rather than execute them.
 	dryRun bool
 	// only consider hosted zones managing domains ending in this suffix
-	domainFilter string
+	domainFilter DomainFilter
 	// A client for managing resource record sets
 	resourceRecordSetsClient resourceRecordSetsClientInterface
 	// A client for managing hosted zones
@@ -106,7 +106,7 @@ type GoogleProvider struct {
 }
 
 // NewGoogleProvider initializes a new Google CloudDNS based Provider.
-func NewGoogleProvider(project string, domainFilter string, dryRun bool) (*GoogleProvider, error) {
+func NewGoogleProvider(project string, domainFilter DomainFilter, dryRun bool) (*GoogleProvider, error) {
 	gcloud, err := google.DefaultClient(context.TODO(), dns.NdevClouddnsReadwriteScope)
 	if err != nil {
 		return nil, err
@@ -142,7 +142,7 @@ func (p *GoogleProvider) Zones() (map[string]*dns.ManagedZone, error) {
 
 	f := func(resp *dns.ManagedZonesListResponse) error {
 		for _, zone := range resp.ManagedZones {
-			if strings.HasSuffix(zone.DnsName, p.domainFilter) {
+			if p.domainFilter.Match(zone.DnsName) {
 				zones[zone.Name] = zone
 			}
 		}

provider/google_test.go

@@ -192,7 +192,7 @@ func hasTrailingDot(target string) bool {
 }
 
 func TestGoogleZones(t *testing.T) {
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	zones, err := provider.Zones()
 	require.NoError(t, err)
@@ -211,7 +211,7 @@ func TestGoogleRecords(t *testing.T) {
 		endpoint.NewEndpoint("list-test-alias.zone-1.ext-dns-test-2.gcp.zalan.do", "foo.elb.amazonaws.com", "CNAME"),
 	}
 
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, originalEndpoints)
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, originalEndpoints)
 
 	records, err := provider.Records()
 	require.NoError(t, err)
@@ -220,7 +220,7 @@ func TestGoogleRecords(t *testing.T) {
 }
 
 func TestGoogleCreateRecords(t *testing.T) {
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, []*endpoint.Endpoint{})
 
 	records := []*endpoint.Endpoint{
 		endpoint.NewEndpoint("create-test.zone-1.ext-dns-test-2.gcp.zalan.do", "1.2.3.4", ""),
@@ -241,7 +241,7 @@ func TestGoogleCreateRecords(t *testing.T) {
 }
 
 func TestGoogleUpdateRecords(t *testing.T) {
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, []*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"),
@@ -277,7 +277,7 @@ func TestGoogleDeleteRecords(t *testing.T) {
 		endpoint.NewEndpoint("delete-test-cname.zone-1.ext-dns-test-2.gcp.zalan.do", "baz.elb.amazonaws.com", "CNAME"),
 	}
 
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, originalEndpoints)
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, originalEndpoints)
 
 	require.NoError(t, provider.DeleteRecords(originalEndpoints))
 
@@ -288,7 +288,7 @@ func TestGoogleDeleteRecords(t *testing.T) {
 }
 
 func TestGoogleApplyChanges(t *testing.T) {
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, []*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"),
@@ -352,7 +352,7 @@ func TestGoogleApplyChangesDryRun(t *testing.T) {
 		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)
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"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"),
@@ -393,7 +393,7 @@ func TestGoogleApplyChangesDryRun(t *testing.T) {
 }
 
 func TestGoogleApplyChangesEmpty(t *testing.T) {
-	provider := newGoogleProvider(t, "ext-dns-test-2.gcp.zalan.do.", false, []*endpoint.Endpoint{})
+	provider := newGoogleProvider(t, NewDomainFilter([]string{"ext-dns-test-2.gcp.zalan.do."}), false, []*endpoint.Endpoint{})
 	assert.NoError(t, provider.ApplyChanges(&plan.Changes{}))
 }
 
@@ -496,7 +496,7 @@ func validateChangeRecord(t *testing.T, record *dns.ResourceRecordSet, expected
 	assert.Equal(t, expected.Ttl, record.Ttl)
 }
 
-func newGoogleProvider(t *testing.T, domainFilter string, dryRun bool, records []*endpoint.Endpoint) *GoogleProvider {
+func newGoogleProvider(t *testing.T, domainFilter DomainFilter, dryRun bool, records []*endpoint.Endpoint) *GoogleProvider {
 	provider := &GoogleProvider{
 		project:      "zalando-external-dns-test",
 		domainFilter: domainFilter,

provider/inmemory.go

@@ -42,7 +42,7 @@ var (
 // InMemoryProvider - dns provider only used for testing purposes
 // initialized as dns provider with no records
 type InMemoryProvider struct {
-	domain         string
+	domain         DomainFilter
 	client         *inMemoryClient
 	filter         *filter
 	OnApplyChanges func(changes *plan.Changes)
@@ -73,9 +73,9 @@ func InMemoryWithLogging() InMemoryOption {
 }
 
 // InMemoryWithDomain modifies the domain on which dns zones are filtered
-func InMemoryWithDomain(domain string) InMemoryOption {
+func InMemoryWithDomain(domainFilter DomainFilter) InMemoryOption {
 	return func(p *InMemoryProvider) {
-		p.domain = domain
+		p.domain = domainFilter
 	}
 }
 
@@ -85,7 +85,7 @@ func NewInMemoryProvider(opts ...InMemoryOption) *InMemoryProvider {
 		filter:         &filter{},
 		OnApplyChanges: func(changes *plan.Changes) {},
 		OnRecords:      func() {},
-		domain:         "",
+		domain:         NewDomainFilter([]string{""}),
 		client:         newInMemoryClient(),
 	}