plugin/k8s: Use service IP index in reverse lookups (#1212)

* use index for svc reverse lookup

* temp revert

* restore reverse.go

* restore reverse_test.go

plugin/kubernetes/reverse.go

@@ -25,14 +25,12 @@ func (k *Kubernetes) Reverse(state request.Request, exact bool, opt plugin.Optio
 // If a service cluster ip does not match, it checks all endpoints
 func (k *Kubernetes) serviceRecordForIP(ip, name string) []msg.Service {
 	// First check services with cluster ips
-	for _, service := range k.APIConn.ServiceList() {
+	for _, service := range k.APIConn.SvcIndexReverse(ip) {
 		if (len(k.Namespaces) > 0) && !k.namespaceExposed(service.Namespace) {
 			continue
 		}
-		if service.Spec.ClusterIP == ip {
-			domain := strings.Join([]string{service.Name, service.Namespace, Svc, k.primaryZone()}, ".")
-			return []msg.Service{{Host: domain}}
-		}
+		domain := strings.Join([]string{service.Name, service.Namespace, Svc, k.primaryZone()}, ".")
+		return []msg.Service{{Host: domain}}
 	}
 	// If no cluster ips match, search endpoints
 	for _, ep := range k.APIConn.EpIndexReverse(ip) {

plugin/kubernetes/reverse_test.go

@@ -14,16 +14,19 @@ import (
 
 type APIConnReverseTest struct{}
 
-func (APIConnReverseTest) HasSynced() bool                       { return true }
-func (APIConnReverseTest) Run()                                  { return }
-func (APIConnReverseTest) Stop() error                           { return nil }
-func (APIConnReverseTest) PodIndex(string) []*api.Pod            { return nil }
-func (APIConnReverseTest) SvcIndex(string) []*api.Service        { return nil }
-func (APIConnReverseTest) SvcIndexReverse(string) []*api.Service { return nil }
-func (APIConnReverseTest) EpIndex(string) []*api.Endpoints       { return nil }
-func (APIConnReverseTest) EndpointsList() []*api.Endpoints       { return nil }
+func (APIConnReverseTest) HasSynced() bool                 { return true }
+func (APIConnReverseTest) Run()                            { return }
+func (APIConnReverseTest) Stop() error                     { return nil }
+func (APIConnReverseTest) PodIndex(string) []*api.Pod      { return nil }
+func (APIConnReverseTest) SvcIndex(string) []*api.Service  { return nil }
+func (APIConnReverseTest) EpIndex(string) []*api.Endpoints { return nil }
+func (APIConnReverseTest) EndpointsList() []*api.Endpoints { return nil }
+func (APIConnReverseTest) ServiceList() []*api.Service     { return nil }
 
-func (APIConnReverseTest) ServiceList() []*api.Service {
+func (APIConnReverseTest) SvcIndexReverse(ip string) []*api.Service {
+	if ip != "192.168.1.100" {
+		return nil
+	}
 	svcs := []*api.Service{
 		{
 			ObjectMeta: meta.ObjectMeta{
@@ -43,7 +46,10 @@ func (APIConnReverseTest) ServiceList() []*api.Service {
 	return svcs
 }
 
-func (APIConnReverseTest) EpIndexReverse(string) []*api.Endpoints {
+func (APIConnReverseTest) EpIndexReverse(ip string) []*api.Endpoints {
+	if ip != "10.0.0.100" {
+		return nil
+	}
 	eps := []*api.Endpoints{
 		{
 			Subsets: []api.EndpointSubset{
@@ -82,7 +88,7 @@ func (APIConnReverseTest) GetNodeByName(name string) (*api.Node, error) {
 
 func TestReverse(t *testing.T) {
 
-	k := New([]string{"cluster.local.", "0.10.in-addr.arpa."})
+	k := New([]string{"cluster.local.", "0.10.in-addr.arpa.", "168.192.in-addr.arpa."})
 	k.APIConn = &APIConnReverseTest{}
 
 	tests := []test.Case{
@@ -93,6 +99,13 @@ func TestReverse(t *testing.T) {
 				test.PTR("100.0.0.10.in-addr.arpa.      303    IN      PTR       ep1a.svc1.testns.svc.cluster.local."),
 			},
 		},
+		{
+			Qname: "100.1.168.192.in-addr.arpa.", Qtype: dns.TypePTR,
+			Rcode: dns.RcodeSuccess,
+			Answer: []dns.RR{
+				test.PTR("100.1.168.192.in-addr.arpa.      303    IN      PTR       svc1.testns.svc.cluster.local."),
+			},
+		},
 		{
 			Qname: "101.0.0.10.in-addr.arpa.", Qtype: dns.TypePTR,
 			Rcode: dns.RcodeSuccess,