Handle publish-not-ready-addresses annotation in CoreDNS plugin

Signed-off-by: Automated Release <[email protected]>

coredns/constants/constants.go

@@ -19,9 +19,10 @@ limitations under the License.
 package constants
 
 const (
-	KubernetesServiceName = "kubernetes.io/service-name"
-	LabelValueManagedBy   = "lighthouse-agent.submariner.io"
-	LabelSourceNamespace  = "lighthouse.submariner.io/sourceNamespace"
-	MCSLabelSourceCluster = "multicluster.kubernetes.io/source-cluster"
-	LabelIsHeadless       = "lighthouse.submariner.io/is-headless"
+	KubernetesServiceName    = "kubernetes.io/service-name"
+	LabelValueManagedBy      = "lighthouse-agent.submariner.io"
+	LabelSourceNamespace     = "lighthouse.submariner.io/sourceNamespace"
+	MCSLabelSourceCluster    = "multicluster.kubernetes.io/source-cluster"
+	LabelIsHeadless          = "lighthouse.submariner.io/is-headless"
+	PublishNotReadyAddresses = "lighthouse.submariner.io/publish-not-ready-addresses"
 )

coredns/resolver/endpoint_slice.go

@@ -21,6 +21,7 @@ package resolver
 import (
 	"context"
 	"fmt"
+	"strconv"
 
 	"github.com/submariner-io/admiral/pkg/log"
 	"github.com/submariner-io/lighthouse/coredns/constants"
@@ -132,12 +133,15 @@ func (i *Interface) putHeadlessEndpointSlice(key, clusterID string, endpointSlic
 
 	mcsPorts := mcsServicePortsFrom(endpointSlice.Ports)
 
+	publishNotReadyAddresses := endpointSlice.Annotations[constants.PublishNotReadyAddresses] == strconv.FormatBool(true)
+
 	for i := range endpointSlice.Endpoints {
 		endpoint := &endpointSlice.Endpoints[i]
 
-		// Skip if not ready. Note: we're treating nil as ready to be on the safe side as the EndpointConditions doc
-		// states "In most cases consumers should interpret this unknown state (ie nil) as ready".
-		if endpoint.Conditions.Ready != nil && !*endpoint.Conditions.Ready {
+		// Skip if not ready and the user does not want to publish not-ready addresses. Note: we're treating nil as ready
+		// to be on the safe side as the EndpointConditions doc states "In most cases consumers should interpret this
+		// unknown state (ie nil) as ready".
+		if endpoint.Conditions.Ready != nil && !*endpoint.Conditions.Ready && !publishNotReadyAddresses {
 			continue
 		}
 

coredns/resolver/headless_service_test.go

@@ -19,6 +19,8 @@ limitations under the License.
 package resolver_test
 
 import (
+	"strconv"
+
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 	"github.com/submariner-io/lighthouse/coredns/constants"
@@ -31,10 +33,120 @@ import (
 
 var _ = Describe("GetDNSRecords", func() {
 	Describe("Headless Service", func() {
+		testHeadlessService()
 		When("a service is present in multiple clusters", testHeadlessServiceInMultipleClusters)
 	})
 })
 
+func testHeadlessService() {
+	t := newTestDriver()
+
+	BeforeEach(func() {
+		t.resolver.PutServiceImport(newHeadlessAggregatedServiceImport(namespace1, service1))
+	})
+
+	When("a service has both ready and not-ready addresses", func() {
+		var annotations map[string]string
+
+		BeforeEach(func() {
+			annotations = nil
+		})
+
+		JustBeforeEach(func() {
+			eps := newEndpointSlice(namespace1, service1, clusterID1, []mcsv1a1.ServicePort{port1},
+				discovery.Endpoint{
+					Addresses:  []string{endpointIP1},
+					Conditions: discovery.EndpointConditions{Ready: &ready},
+				},
+				discovery.Endpoint{
+					Addresses:  []string{endpointIP2},
+					Conditions: discovery.EndpointConditions{Ready: &notReady},
+				},
+				discovery.Endpoint{
+					Addresses:  []string{endpointIP3},
+					Conditions: discovery.EndpointConditions{Ready: &ready},
+				},
+				discovery.Endpoint{
+					Addresses:  []string{endpointIP4},
+					Conditions: discovery.EndpointConditions{Ready: &notReady},
+				},
+			)
+			eps.Annotations = annotations
+
+			t.putEndpointSlice(eps)
+		})
+
+		Context("and the publish-not-ready-addresses annotation is not present", func() {
+			It("should return DNS records for only the ready addresses", func() {
+				t.assertDNSRecordsFound(namespace1, service1, "", "", true,
+					resolver.DNSRecord{
+						IP:          endpointIP1,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+					resolver.DNSRecord{
+						IP:          endpointIP3,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+				)
+			})
+		})
+
+		Context("and the publish-not-ready-addresses annotation is set to false", func() {
+			BeforeEach(func() {
+				annotations = map[string]string{constants.PublishNotReadyAddresses: strconv.FormatBool(false)}
+			})
+
+			It("should return DNS records for only the ready addresses", func() {
+				t.assertDNSRecordsFound(namespace1, service1, "", "", true,
+					resolver.DNSRecord{
+						IP:          endpointIP1,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+					resolver.DNSRecord{
+						IP:          endpointIP3,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+				)
+			})
+		})
+
+		Context("and the publish-not-ready-addresses annotation is set to true", func() {
+			BeforeEach(func() {
+				annotations = map[string]string{constants.PublishNotReadyAddresses: strconv.FormatBool(true)}
+			})
+
+			It("should return all the DNS records", func() {
+				t.assertDNSRecordsFound(namespace1, service1, "", "", true,
+					resolver.DNSRecord{
+						IP:          endpointIP1,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+					resolver.DNSRecord{
+						IP:          endpointIP2,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+					resolver.DNSRecord{
+						IP:          endpointIP3,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+					resolver.DNSRecord{
+						IP:          endpointIP4,
+						Ports:       []mcsv1a1.ServicePort{port1},
+						ClusterName: clusterID1,
+					},
+				)
+			})
+		})
+	})
+}
+
 func testHeadlessServiceInMultipleClusters() {
 	t := newTestDriver()
 
@@ -106,10 +218,7 @@ func testHeadlessServiceInMultipleClusters() {
 				Hostname:  &hostName2,
 				NodeName:  &nodeName3,
 			},
-			discovery.Endpoint{
-				Addresses:  []string{"1.2.3.4"},
-				Conditions: discovery.EndpointConditions{Ready: &notReady},
-			}))
+		))
 	})
 
 	Context("and no specific cluster is requested", func() {