feat: allow to register and lookup sources by name (#84)

main.go

@@ -74,7 +74,10 @@ func main() {
 		log.Fatal(err)
 	}
 
-	source := source.NewServiceSource(client, cfg.Namespace)
+	source.Register("service", source.NewServiceSource(client, cfg.Namespace))
+	source.Register("ingress", source.NewIngressSource(client, cfg.Namespace))
+
+	sources := source.NewMultiSource(source.LookupMultiple(cfg.Sources...)...)
 
 	dnsProvider, err := dnsprovider.NewGoogleProvider(cfg.GoogleProject, cfg.DryRun)
 	if err != nil {
@@ -83,7 +86,7 @@ func main() {
 
 	ctrl := controller.Controller{
 		Zone:        cfg.GoogleZone,
-		Source:      source,
+		Source:      sources,
 		DNSProvider: dnsProvider,
 	}
 

pkg/apis/externaldns/types.go

@@ -32,6 +32,7 @@ type Config struct {
 	InCluster     bool
 	KubeConfig    string
 	Namespace     string
+	Sources       []string
 	GoogleProject string
 	GoogleZone    string
 	HealthPort    string
@@ -53,6 +54,7 @@ func (cfg *Config) ParseFlags(args []string) error {
 	flags.BoolVar(&cfg.InCluster, "in-cluster", false, "whether to use in-cluster config")
 	flags.StringVar(&cfg.KubeConfig, "kubeconfig", "", "path to a local kubeconfig file")
 	flags.StringVar(&cfg.Namespace, "namespace", v1.NamespaceAll, "the namespace to look for endpoints; all namespaces by default")
+	flags.StringArrayVar(&cfg.Sources, "source", nil, "the sources to gather endpoints from")
 	flags.StringVar(&cfg.GoogleProject, "google-project", "", "gcloud project to target")
 	flags.StringVar(&cfg.GoogleZone, "google-zone", "", "gcloud dns hosted zone to target")
 	flags.StringVar(&cfg.HealthPort, "health-port", defaultHealthPort, "health port to listen on")

source/store.go

@@ -0,0 +1,38 @@
+/*
+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 source
+
+var store = map[string]Source{}
+
+// Register registers a Source under a given name.
+func Register(name string, source Source) {
+	store[name] = source
+}
+
+// Lookup returns a Source by the given name.
+func Lookup(name string) Source {
+	return store[name]
+}
+
+// LookupMultiple returns multiple Sources given multiple names.
+func LookupMultiple(names ...string) (sources []Source) {
+	for _, name := range names {
+		sources = append(sources, Lookup(name))
+	}
+
+	return sources
+}

source/store_test.go

@@ -0,0 +1,87 @@
+/*
+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 source
+
+import "testing"
+
+func TestStore(t *testing.T) {
+	t.Run("RegisterAndLookup", testRegisterAndLookup)
+	t.Run("LookupMultiple", testLookupMultiple)
+}
+
+// testRegisterAndLookup tests that a Source can be registered and looked up by name.
+func testRegisterAndLookup(t *testing.T) {
+	for _, tc := range []struct {
+		title            string
+		givenAndExpected map[string]Source
+	}{
+		{
+			"registered source is found by name",
+			map[string]Source{
+				"foo": NewMockSource(nil),
+			},
+		},
+	} {
+		t.Run(tc.title, func(t *testing.T) {
+			for k, v := range tc.givenAndExpected {
+				Register(k, v)
+			}
+
+			for k, v := range tc.givenAndExpected {
+				if Lookup(k) != v {
+					t.Errorf("expected %#v, got %#v", v, Lookup(k))
+				}
+			}
+		})
+	}
+}
+
+// testLookupMultiple tests that Sources can be looked up by providing multiple names.
+func testLookupMultiple(t *testing.T) {
+	for _, tc := range []struct {
+		title            string
+		givenAndExpected map[string]Source
+	}{
+		{
+			"multiple registered sources are found by names",
+			map[string]Source{
+				"foo": NewMockSource(nil),
+				"bar": NewMockSource(nil),
+			},
+		},
+	} {
+		t.Run(tc.title, func(t *testing.T) {
+			for k, v := range tc.givenAndExpected {
+				Register(k, v)
+			}
+
+			names, sources := []string{}, []Source{}
+			for k, v := range tc.givenAndExpected {
+				names = append(names, k)
+				sources = append(sources, v)
+			}
+
+			lookup := LookupMultiple(names...)
+
+			for i := range names {
+				if lookup[i] != sources[i] {
+					t.Errorf("expected %#v, got %#v", sources[i], lookup[i])
+				}
+			}
+		})
+	}
+}