Merge afc7788578 into 0e7c3af221

docs/sources/service.md

@@ -33,6 +33,10 @@ a Pod that has a non-empty `spec.hostname` field, additional DNS entries are cre
 For each domain name created for the Service, the additional DNS entry for the Pod has that domain name prefixed with
 the value of the Pod's `spec.hostname` field and a `.`.
 
+Another way to create per-pod DNS entries is to annotate headless service with
+`external-dns.alpha.kubernetes.io/service-pod-endpoints` and values `pod-name` or `fqdn-template`. The former prefixes
+service domain name with pod name, the latter uses `--fqdn-template` to generate the domain name for each pod in the service.
+
 ## Targets
 
 If the Service has an `external-dns.alpha.kubernetes.io/target` annotation, uses

source/annotations/annotations.go

@@ -55,4 +55,6 @@ const (
 	ControllerValue = "dns-controller"
 	// The annotation used for defining the desired hostname
 	InternalHostnameKey = AnnotationKeyPrefix + "internal-hostname"
+	// When set on a service, per-pod DNS entries will be created.
+	ServicePodEndpoints = AnnotationKeyPrefix + "service-pod-endpoints"
 )

source/service.go

@@ -314,6 +314,8 @@ func (sc *serviceSource) extractHeadlessEndpoints(svc *v1.Service, hostname stri
 	publishPodIPs := endpointsType != EndpointsTypeNodeExternalIP && endpointsType != EndpointsTypeHostIP && !sc.publishHostIP
 	publishNotReadyAddresses := svc.Spec.PublishNotReadyAddresses || sc.alwaysPublishNotReadyAddresses
 
+	perPodDNSMode, perPodDNS := svc.Annotations[servicePodEndpointsKey]
+
 	targetsByHeadlessDomainAndType := make(map[endpoint.EndpointKey]endpoint.Targets)
 	for _, endpointSlice := range endpointSlices {
 		for _, ep := range endpointSlice.Endpoints {
@@ -350,6 +352,21 @@ func (sc *serviceSource) extractHeadlessEndpoints(svc *v1.Service, hostname stri
 				headlessDomains = append(headlessDomains, fmt.Sprintf("%s.%s", pod.Spec.Hostname, hostname))
 			}
 
+                        if perPodDNS {
+				switch perPodDNSMode {
+				case ServicePodEndpointsPodName:
+					headlessDomains = append(headlessDomains, fmt.Sprintf("%s.%s", pod.Name, hostname))
+				case ServicePodEndpointsFqdnTemplate:
+					if hostnames, err := fqdn.ExecTemplate(sc.fqdnTemplate, pod); err == nil {
+						headlessDomains = append(headlessDomains, hostnames...)
+					} else {
+						log.Errorf("Error executing template for pod %s: %v", pod.Name, err)
+					}
+				default:
+					log.Errorf("Unknown `service-pod-endpoints` value %s", perPodDNSMode)
+					return endpoints
+				}
+			}
 			for _, headlessDomain := range headlessDomains {
 				targets := annotations.TargetsFromTargetAnnotation(pod.Annotations)
 				if len(targets) == 0 {

source/service_test.go

@@ -3053,6 +3053,149 @@ func TestHeadlessServices(t *testing.T) {
 			},
 			false,
 		},
+		{
+			"annotated Headless services create DNS name for each pod",
+			"",
+			"testing",
+			"foo",
+			v1.ServiceTypeClusterIP,
+			"",
+			"",
+			false,
+			true,
+			map[string]string{"component": "foo"},
+			map[string]string{
+				servicePodEndpointsKey:     ServicePodEndpointsPodName,
+				hostnameAnnotationKey:      "service.example.org",
+				endpointsTypeAnnotationKey: EndpointsTypeNodeExternalIP,
+			},
+			map[string]string{},
+			v1.ClusterIPNone,
+			[]string{"1.1.1.1", "1.1.1.2", "1.1.1.3"},
+			[]string{"", "", ""},
+			map[string]string{
+				"component": "foo",
+			},
+			[]string{},
+			[]string{"foo1", "foo2", "foo3"},
+			[]string{"", "", ""},
+			[]bool{true, true, true},
+			false,
+			[]v1.Node{
+				{
+					Status: v1.NodeStatus{
+						Addresses: []v1.NodeAddress{
+							{
+								Type:    v1.NodeExternalIP,
+								Address: "1.2.3.4",
+							},
+							{
+								Type:    v1.NodeInternalIP,
+								Address: "2001:db8::4",
+							},
+						},
+					},
+				},
+			},
+			[]*endpoint.Endpoint{
+				{DNSName: "service.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "service.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo1.service.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo1.service.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo2.service.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo2.service.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo3.service.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo3.service.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+			},
+			false,
+		},
+		{
+			"annotated Headless services create DNS name for each pod using fqdn template",
+			"",
+			"testing",
+			"foo",
+			v1.ServiceTypeClusterIP,
+			"",
+			"{{ .Name }}-{{ .Namespace }}.example.org",
+			false,
+			true,
+			map[string]string{"component": "foo"},
+			map[string]string{
+				servicePodEndpointsKey:     ServicePodEndpointsFqdnTemplate,
+				hostnameAnnotationKey:      "service.example.org",
+				endpointsTypeAnnotationKey: EndpointsTypeNodeExternalIP,
+			},
+			map[string]string{},
+			v1.ClusterIPNone,
+			[]string{"1.1.1.1", "1.1.1.2", "1.1.1.3"},
+			[]string{"", "", ""},
+			map[string]string{
+				"component": "foo",
+			},
+			[]string{},
+			[]string{"foo1", "foo2", "foo3"},
+			[]string{"", "", ""},
+			[]bool{true, true, true},
+			false,
+			[]v1.Node{
+				{
+					Status: v1.NodeStatus{
+						Addresses: []v1.NodeAddress{
+							{
+								Type:    v1.NodeExternalIP,
+								Address: "1.2.3.4",
+							},
+							{
+								Type:    v1.NodeInternalIP,
+								Address: "2001:db8::4",
+							},
+						},
+					},
+				},
+			},
+			[]*endpoint.Endpoint{
+				{DNSName: "service.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "service.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo1-testing.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo1-testing.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo2-testing.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo2-testing.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+				{DNSName: "foo3-testing.example.org", RecordType: endpoint.RecordTypeA, Targets: endpoint.Targets{"1.2.3.4"}},
+				{DNSName: "foo3-testing.example.org", RecordType: endpoint.RecordTypeAAAA, Targets: endpoint.Targets{"2001:db8::4"}},
+			},
+			false,
+		},
+		{
+			"annotated Headless service returns error if incorrect `service-pod-endpoints` value is set",
+			"",
+			"testing",
+			"foo",
+			v1.ServiceTypeClusterIP,
+			"",
+			"",
+			false,
+			true,
+			map[string]string{"component": "foo"},
+			map[string]string{
+				servicePodEndpointsKey: "not-valid",
+				hostnameAnnotationKey:  "service.example.org",
+			},
+			map[string]string{},
+			v1.ClusterIPNone,
+			[]string{"1.1.1.1", "1.1.1.2", "1.1.1.3"},
+			[]string{"", "", ""},
+			map[string]string{
+				"component": "foo",
+			},
+			[]string{},
+			[]string{"foo1", "foo2", "foo3"},
+			[]string{"", "", ""},
+			[]bool{true, true, true},
+			false,
+			[]v1.Node{{}},
+			[]*endpoint.Endpoint{},
+			false,
+		},
 		{
 			"annotated Headless services return dual-stack targets from node external IP if endpoints-type annotation is set and exposeInternalIPv6 flag set",
 			"",

source/source.go

@@ -38,9 +38,13 @@ const (
 	ingressHostnameSourceKey      = annotations.IngressHostnameSourceKey
 	controllerAnnotationValue     = annotations.ControllerValue
 	internalHostnameAnnotationKey = annotations.InternalHostnameKey
+	servicePodEndpointsKey        = annotations.ServicePodEndpoints
 
 	EndpointsTypeNodeExternalIP = "NodeExternalIP"
 	EndpointsTypeHostIP         = "HostIP"
+
+	ServicePodEndpointsPodName      = "pod-name"
+	ServicePodEndpointsFqdnTemplate = "fqdn-template"
 )
 
 // Source defines the interface Endpoint sources should implement.