Support for multiple hostnames in hostname annotation (#256)

* service source: support for multiple hostnames per annotation

* go fmt

* Make parseHostnameAnnontations inline

* Update CHANGELOG.md

* Update Changelog

CHANGELOG.md

@@ -1,3 +1,4 @@
+  - The `external-dns.alpha.kubernetes.io/hostname` annotation accepts now a comma separated list of hostnames and a trailing period is not required anymore.
   - 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.
   

source/service.go

@@ -140,11 +140,16 @@ func endpointsFromService(svc *v1.Service) []*endpoint.Endpoint {
 	var endpoints []*endpoint.Endpoint
 
 	// Get the desired hostname of the service from the annotation.
-	hostname, exists := svc.Annotations[hostnameAnnotationKey]
+	hostnameAnnotation, exists := svc.Annotations[hostnameAnnotationKey]
 	if !exists {
 		return nil
 	}
 
+	// splits the hostname annotation and removes the trailing periods
+	hostnameList := strings.Split(strings.Replace(hostnameAnnotation, " ", "", -1), ",")
+
+	for _, hostname := range hostnameList {
+		hostname = strings.TrimSuffix(hostname, ".")
 		// Create a corresponding endpoint for each configured external entrypoint.
 		for _, lb := range svc.Status.LoadBalancer.Ingress {
 			if lb.IP != "" {
@@ -155,6 +160,7 @@ func endpointsFromService(svc *v1.Service) []*endpoint.Endpoint {
 				endpoints = append(endpoints, endpoint.NewEndpoint(hostname, lb.Hostname, ""))
 			}
 		}
+	}
 
 	return endpoints
 }

source/service_test.go

@@ -125,6 +125,42 @@ func testServiceSourceEndpoints(t *testing.T) {
 			},
 			false,
 		},
+		{
+			"annotated services with multiple hostnames return an endpoint with target IP",
+			"",
+			"testing",
+			"foo",
+			"",
+			"",
+			map[string]string{},
+			map[string]string{
+				hostnameAnnotationKey: "foo.example.org., bar.example.org.",
+			},
+			[]string{"1.2.3.4"},
+			[]*endpoint.Endpoint{
+				{DNSName: "foo.example.org", Target: "1.2.3.4"},
+				{DNSName: "bar.example.org", Target: "1.2.3.4"},
+			},
+			false,
+		},
+		{
+			"annotated services with multiple hostnames and without trailing period return an endpoint with target IP",
+			"",
+			"testing",
+			"foo",
+			"",
+			"",
+			map[string]string{},
+			map[string]string{
+				hostnameAnnotationKey: "foo.example.org, bar.example.org",
+			},
+			[]string{"1.2.3.4"},
+			[]*endpoint.Endpoint{
+				{DNSName: "foo.example.org", Target: "1.2.3.4"},
+				{DNSName: "bar.example.org", Target: "1.2.3.4"},
+			},
+			false,
+		},
 		{
 			"annotated services return an endpoint with target hostname",
 			"",