use constructor methods to create sources (#82)

* ref(source): use constructor methods to create sources

* fix: import and use missing package

* fix(source): fix merge conflict with master branch

main.go

@@ -74,10 +74,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	source := &source.ServiceSource{
-		Client:    client,
-		Namespace: cfg.Namespace,
-	}
+	source := source.NewServiceSource(client, cfg.Namespace)
 
 	dnsProvider, err := dnsprovider.NewGoogleProvider(cfg.GoogleProject, cfg.DryRun)
 	if err != nil {

source/ingress.go

@@ -24,18 +24,23 @@ import (
 	"github.com/kubernetes-incubator/external-dns/endpoint"
 )
 
-// IngressSource is an implementation of Source for Kubernetes ingress objects.
+// ingressSource is an implementation of Source for Kubernetes ingress objects.
 // Ingress implementation will use the spec.rules.host value for the hostname
 // Ingress annotations are ignored
-type IngressSource struct {
-	Client    kubernetes.Interface
-	Namespace string
+type ingressSource struct {
+	client    kubernetes.Interface
+	namespace string
+}
+
+// NewIngressSource creates a new ingressSource with the given client and namespace scope.
+func NewIngressSource(client kubernetes.Interface, namespace string) Source {
+	return &ingressSource{client: client, namespace: namespace}
 }
 
 // Endpoints returns endpoint objects for each host-target combination that should be processed.
 // Retrieves all ingress resources on all namespaces
-func (sc *IngressSource) Endpoints() ([]endpoint.Endpoint, error) {
-	ingresses, err := sc.Client.Extensions().Ingresses(sc.Namespace).List(v1.ListOptions{})
+func (sc *ingressSource) Endpoints() ([]endpoint.Endpoint, error) {
+	ingresses, err := sc.client.Extensions().Ingresses(sc.namespace).List(v1.ListOptions{})
 	if err != nil {
 		return nil, err
 	}

source/ingress_test.go

@@ -25,8 +25,8 @@ import (
 	"k8s.io/client-go/pkg/apis/extensions/v1beta1"
 )
 
-// Validates that IngressSource is a Source
-var _ Source = &IngressSource{}
+// Validates that ingressSource is a Source
+var _ Source = &ingressSource{}
 
 func TestIngress(t *testing.T) {
 	t.Run("endpointsFromIngress", testEndpointsFromIngress)
@@ -223,10 +223,7 @@ func testIngressEndpoints(t *testing.T) {
 			}
 
 			fakeClient := fake.NewSimpleClientset()
-			ingressSource := &IngressSource{
-				Client:    fakeClient,
-				Namespace: ti.targetNamespace,
-			}
+			ingressSource := NewIngressSource(fakeClient, ti.targetNamespace)
 			for _, ingress := range ingresses {
 				_, err := fakeClient.Extensions().Ingresses(ingress.Namespace).Create(ingress)
 				if err != nil {

source/service.go

@@ -32,19 +32,24 @@ const (
 	controllerAnnotationValue = "dns-controller"
 )
 
-// ServiceSource is an implementation of Source for Kubernetes service objects.
+// serviceSource is an implementation of Source for Kubernetes service objects.
 // It will find all services that are under our jurisdiction, i.e. annotated
 // desired hostname and matching or no controller annotation. For each of the
 // matched services' external entrypoints it will return a corresponding
 // Endpoint object.
-type ServiceSource struct {
-	Client    kubernetes.Interface
-	Namespace string
+type serviceSource struct {
+	client    kubernetes.Interface
+	namespace string
+}
+
+// NewServiceSource creates a new serviceSource with the given client and namespace scope.
+func NewServiceSource(client kubernetes.Interface, namespace string) Source {
+	return &serviceSource{client: client, namespace: namespace}
 }
 
 // Endpoints returns endpoint objects for each service that should be processed.
-func (sc *ServiceSource) Endpoints() ([]endpoint.Endpoint, error) {
-	services, err := sc.Client.CoreV1().Services(sc.Namespace).List(v1.ListOptions{})
+func (sc *serviceSource) Endpoints() ([]endpoint.Endpoint, error) {
+	services, err := sc.client.CoreV1().Services(sc.namespace).List(v1.ListOptions{})
 	if err != nil {
 		return nil, err
 	}

source/service_test.go

@@ -26,8 +26,8 @@ import (
 	"github.com/kubernetes-incubator/external-dns/endpoint"
 )
 
-// Validates that ServiceSource is a Source
-var _ Source = &ServiceSource{}
+// Validates that serviceSource is a Source
+var _ Source = &serviceSource{}
 
 func TestService(t *testing.T) {
 	t.Run("Endpoints", testServiceEndpoints)
@@ -201,10 +201,7 @@ func testServiceEndpoints(t *testing.T) {
 			}
 
 			// Create our object under test and get the endpoints.
-			client := &ServiceSource{
-				Client:    kubernetes,
-				Namespace: tc.targetNamespace,
-			}
+			client := NewServiceSource(kubernetes, tc.targetNamespace)
 
 			endpoints, err := client.Endpoints()
 			if err != nil {
@@ -243,9 +240,7 @@ func BenchmarkServiceEndpoints(b *testing.B) {
 		b.Fatal(err)
 	}
 
-	client := &ServiceSource{
-		Client: kubernetes,
-	}
+	client := NewServiceSource(kubernetes, v1.NamespaceAll)
 
 	for i := 0; i < b.N; i++ {
 		_, err := client.Endpoints()