handle clusterIP endpoint queries (#730)

middleware/kubernetes/kubernetes.go

@@ -366,6 +366,7 @@ func (k *Kubernetes) Records(r recordRequest) ([]msg.Service, error) {
 	}
 
 	records := k.getRecordsForK8sItems(services, pods, r)
+
 	return records, nil
 }
 
@@ -386,8 +387,8 @@ func (k *Kubernetes) getRecordsForK8sItems(services []service, pods []pod, r rec
 	zonePath := msg.Path(r.zone, "coredns")
 
 	for _, svc := range services {
-		if svc.addr == api.ClusterIPNone {
+		if svc.addr == api.ClusterIPNone || len(svc.endpoints) > 0 {
-			// This is a headless service, create records for each endpoint
+			// This is a headless service or endpoints are present, create records for each endpoint
 			for _, ep := range svc.endpoints {
 				s := msg.Service{
 					Host: ep.addr.IP,
@@ -522,28 +523,11 @@ func (k *Kubernetes) findServices(r recordRequest) ([]service, error) {
 			continue
 		}
 		s := service{name: svc.Name, namespace: svc.Namespace}
-		// External Service
+
-		if svc.Spec.ExternalName != "" {
+		// Endpoint query or headless service
-			s.addr = svc.Spec.ExternalName
+		if svc.Spec.ClusterIP == api.ClusterIPNone || r.endpoint != "" {
-			resultItems = append(resultItems, s)
-			continue
-		}
-		// ClusterIP service
-		if svc.Spec.ClusterIP != api.ClusterIPNone {
-			s.addr = svc.Spec.ClusterIP
-			for _, p := range svc.Spec.Ports {
-				if !(symbolMatches(r.port, strings.ToLower(p.Name), portWildcard) && symbolMatches(r.protocol, strings.ToLower(string(p.Protocol)), protocolWildcard)) {
-					continue
-				}
-				s.ports = append(s.ports, p)
-			}
-			resultItems = append(resultItems, s)
-			continue
-		}
-		// Headless service
 			s.addr = svc.Spec.ClusterIP
 			endpointsList := k.APIConn.EndpointsList()
-
 			for _, ep := range endpointsList.Items {
 				if ep.ObjectMeta.Name != svc.Name || ep.ObjectMeta.Namespace != svc.Namespace {
 					continue
@@ -563,6 +547,28 @@ func (k *Kubernetes) findServices(r recordRequest) ([]service, error) {
 					}
 				}
 			}
+			if len(s.endpoints) > 0 {
+				resultItems = append(resultItems, s)
+			}
+			continue
+		}
+
+		// External service
+		if svc.Spec.ExternalName != "" {
+			s.addr = svc.Spec.ExternalName
+			resultItems = append(resultItems, s)
+			continue
+		}
+
+		// ClusterIP service
+		s.addr = svc.Spec.ClusterIP
+		for _, p := range svc.Spec.Ports {
+			if !(symbolMatches(r.port, strings.ToLower(p.Name), portWildcard) && symbolMatches(r.protocol, strings.ToLower(string(p.Protocol)), protocolWildcard)) {
+				continue
+			}
+			s.ports = append(s.ports, p)
+		}
+
 		resultItems = append(resultItems, s)
 	}
 	return resultItems, nil

middleware/kubernetes/kubernetes_test.go

@@ -349,6 +349,7 @@ func (APIConnServiceTest) EndpointsList() api.EndpointsList {
 						Addresses: []api.EndpointAddress{
 							{
 								IP:       "172.0.0.1",
+								Hostname: "ep1a",
 							},
 						},
 						Ports: []api.EndpointPort{
@@ -455,6 +456,7 @@ func TestServices(t *testing.T) {
 		// Cluster IP Services
 		{qname: "svc1.testns.svc.interwebs.test.", qtype: dns.TypeA, answer: svcAns{host: "10.0.0.1", key: "/coredns/test/interwebs/svc/testns/svc1"}},
 		{qname: "_http._tcp.svc1.testns.svc.interwebs.test.", qtype: dns.TypeSRV, answer: svcAns{host: "10.0.0.1", key: "/coredns/test/interwebs/svc/testns/svc1"}},
+		{qname: "ep1a.svc1.testns.svc.interwebs.test.", qtype: dns.TypeA, answer: svcAns{host: "172.0.0.1", key: "/coredns/test/interwebs/svc/testns/svc1/ep1a"}},
 
 		// External Services
 		{qname: "external.testns.svc.interwebs.test.", qtype: dns.TypeCNAME, answer: svcAns{host: "coredns.io", key: "/coredns/test/interwebs/svc/testns/external"}},

test/kubernetes_test.go

@@ -29,6 +29,16 @@ var dnsTestCases = []test.Case{
 		Rcode:  dns.RcodeNameError,
 		Answer: []dns.RR{},
 	},
+	{
+		Qname: "bogusendpoint.svc-1-a.test-1.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeNameError,
+		Answer: []dns.RR{},
+	},
+	{
+		Qname: "bogusendpoint.headless-svc.test-1.svc.cluster.local.", Qtype: dns.TypeA,
+		Rcode:  dns.RcodeNameError,
+		Answer: []dns.RR{},
+	},
 	{
 		Qname: "svc-1-a.*.svc.cluster.local.", Qtype: dns.TypeA,
 		Rcode: dns.RcodeSuccess,