Support dns-controller compat mode for pod source

README.md

@@ -284,7 +284,7 @@ Here's a rough outline on what is to come (subject to change):
 
 - [ ] Ability to replace Kops' [DNS Controller](https://github.com/kubernetes/kops/tree/HEAD/dns-controller)
 	- [x] Add support for pod source
-	- [ ] Add support for DNS Controller annotations for pod, ingress, and service sources
+	- [x] Add support for DNS Controller annotations for pod and service sources
 	- [ ] Add support for kOps gossip provider
 - [x] Ability to replace Zalando's [Mate](https://github.com/linki/mate)
 - [x] Ability to replace Molecule Software's [route53-kubernetes](https://github.com/wearemolecule/route53-kubernetes)

source/pod.go

@@ -34,14 +34,15 @@ import (
 )
 
 type podSource struct {
-	client       kubernetes.Interface
+	client        kubernetes.Interface
-	namespace    string
+	namespace     string
-	podInformer  coreinformers.PodInformer
+	podInformer   coreinformers.PodInformer
-	nodeInformer coreinformers.NodeInformer
+	nodeInformer  coreinformers.NodeInformer
+	compatibility string
 }
 
 // NewPodSource creates a new podSource with the given config.
-func NewPodSource(kubeClient kubernetes.Interface, namespace string) (Source, error) {
+func NewPodSource(kubeClient kubernetes.Interface, namespace string, compatibility string) (Source, error) {
 	informerFactory := kubeinformers.NewSharedInformerFactoryWithOptions(kubeClient, 0, kubeinformers.WithNamespace(namespace))
 	podInformer := informerFactory.Core().V1().Pods()
 	nodeInformer := informerFactory.Core().V1().Nodes()
@@ -71,10 +72,11 @@ func NewPodSource(kubeClient kubernetes.Interface, namespace string) (Source, er
 	}
 
 	return &podSource{
-		client:       kubeClient,
+		client:        kubeClient,
-		podInformer:  podInformer,
+		podInformer:   podInformer,
-		nodeInformer: nodeInformer,
+		nodeInformer:  nodeInformer,
-		namespace:    namespace,
+		namespace:     namespace,
+		compatibility: compatibility,
 	}, nil
 }
 
@@ -114,6 +116,28 @@ func (ps *podSource) Endpoints(ctx context.Context) ([]*endpoint.Endpoint, error
 				}
 			}
 		}
+
+		if ps.compatibility == "dns-controller" {
+			if domain, ok := pod.Annotations[dnsControllerInternalHostnameAnnotationKey]; ok {
+				if _, ok := domains[domain]; !ok {
+					domains[domain] = []string{}
+				}
+				domains[domain] = append(domains[domain], pod.Status.PodIP)
+			}
+
+			if domain, ok := pod.Annotations[dnsControllerHostnameAnnotationKey]; ok {
+				if _, ok := domains[domain]; !ok {
+					domains[domain] = []string{}
+				}
+
+				node, _ := ps.nodeInformer.Lister().Get(pod.Spec.NodeName)
+				for _, address := range node.Status.Addresses {
+					if address.Type == corev1.NodeExternalIP {
+						domains[domain] = append(domains[domain], address.Address)
+					}
+				}
+			}
+		}
 	}
 	endpoints := []*endpoint.Endpoint{}
 	for domain, targets := range domains {

source/pod_test.go

@@ -32,6 +32,7 @@ func TestPodSource(t *testing.T) {
 	for _, tc := range []struct {
 		title           string
 		targetNamespace string
+		compatibility   string
 		expected        []*endpoint.Endpoint
 		expectError     bool
 		nodes           []*corev1.Node
@@ -40,6 +41,7 @@ func TestPodSource(t *testing.T) {
 		{
 			"create records based on pod's external and internal IPs",
 			"",
+			"",
 			[]*endpoint.Endpoint{
 				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1", "54.10.11.2"}, RecordType: endpoint.RecordTypeA},
 				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1", "10.0.1.2"}, RecordType: endpoint.RecordTypeA},
@@ -106,9 +108,80 @@ func TestPodSource(t *testing.T) {
 				},
 			},
 		},
+		{
+			"create records based on pod's external and internal IPs using DNS Controller annotations",
+			"",
+			"dns-controller",
+			[]*endpoint.Endpoint{
+				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1", "54.10.11.2"}, RecordType: endpoint.RecordTypeA},
+				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1", "10.0.1.2"}, RecordType: endpoint.RecordTypeA},
+			},
+			false,
+			[]*corev1.Node{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "my-node1",
+					},
+					Status: corev1.NodeStatus{
+						Addresses: []corev1.NodeAddress{
+							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
+							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
+						},
+					},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "my-node2",
+					},
+					Status: corev1.NodeStatus{
+						Addresses: []corev1.NodeAddress{
+							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
+							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
+						},
+					},
+				},
+			},
+			[]*corev1.Pod{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "my-pod1",
+						Namespace: "kube-system",
+						Annotations: map[string]string{
+							dnsControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
+							dnsControllerHostnameAnnotationKey:         "a.foo.example.org",
+						},
+					},
+					Spec: corev1.PodSpec{
+						HostNetwork: true,
+						NodeName:    "my-node1",
+					},
+					Status: corev1.PodStatus{
+						PodIP: "10.0.1.1",
+					},
+				},
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      "my-pod2",
+						Namespace: "kube-system",
+						Annotations: map[string]string{
+							dnsControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
+							dnsControllerHostnameAnnotationKey:         "a.foo.example.org",
+						},
+					},
+					Spec: corev1.PodSpec{
+						HostNetwork: true,
+						NodeName:    "my-node2",
+					},
+					Status: corev1.PodStatus{
+						PodIP: "10.0.1.2",
+					},
+				},
+			},
+		},
 		{
 			"create multiple records",
 			"",
+			"",
 			[]*endpoint.Endpoint{
 				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
 				{DNSName: "b.foo.example.org", Targets: endpoint.Targets{"54.10.11.2"}, RecordType: endpoint.RecordTypeA},
@@ -176,6 +249,7 @@ func TestPodSource(t *testing.T) {
 		{
 			"pods with hostNetwore=false should be ignored",
 			"",
+			"",
 			[]*endpoint.Endpoint{
 				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
 				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
@@ -245,6 +319,7 @@ func TestPodSource(t *testing.T) {
 		{
 			"only watch a given namespace",
 			"kube-system",
+			"",
 			[]*endpoint.Endpoint{
 				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
 				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
@@ -332,7 +407,7 @@ func TestPodSource(t *testing.T) {
 				}
 			}
 
-			client, err := NewPodSource(kubernetes, tc.targetNamespace)
+			client, err := NewPodSource(kubernetes, tc.targetNamespace, tc.compatibility)
 			require.NoError(t, err)
 
 			endpoints, err := client.Endpoints(ctx)

source/store.go

@@ -193,7 +193,7 @@ func BuildWithConfig(source string, p ClientGenerator, cfg *Config) (Source, err
 		if err != nil {
 			return nil, err
 		}
-		return NewPodSource(client, cfg.Namespace)
+		return NewPodSource(client, cfg.Namespace, cfg.Compatibility)
 	case "istio-gateway":
 		kubernetesClient, err := p.KubeClient()
 		if err != nil {