Allow all headless services, not just those backed by Statefulsets with subdomains (openservicemesh#5250)

* Allow all headless services, not just those backed by Statefulsets with subdomains

Signed-off-by: Keith Mattix II <[email protected]>

Author: keithmattix

.github/workflows/main.yml

@@ -160,7 +160,7 @@ jobs:
       matrix:
         k8s_version: [""]
         focus: [""]
-        bucket: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+        bucket: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
         include:
           - k8s_version: v1.22.9
             focus: "Test traffic flowing from client to server with a Kubernetes Service for the Source: HTTP"

pkg/cli/verifier/envoy_config.go

@@ -18,6 +18,7 @@ import (
 
 	configv1alpha2 "github.com/openservicemesh/osm/pkg/apis/config/v1alpha2"
 	"github.com/openservicemesh/osm/pkg/envoy"
+	"github.com/openservicemesh/osm/pkg/k8s"
 	"github.com/openservicemesh/osm/pkg/trafficpolicy"
 
 	"github.com/openservicemesh/osm/pkg/constants"
@@ -480,11 +481,15 @@ func (v *EnvoyConfigVerifier) getDstMeshServicesForSvcPod(svc corev1.Service, po
 		// us to retrieve the TargetPort for the MeshService.
 		meshSvc.TargetPort = k8s.GetTargetPortFromEndpoints(portSpec.Name, *endpoints)
 
+		// Even if the service is headless, add it so it can be targeted
 		if !k8s.IsHeadlessService(svc) {
 			meshServices = append(meshServices, meshSvc)
 			continue
 		}
 
+		// If there's not at least 1 subdomain-ed MeshService added,
+		// add the entire headless service
+		var added bool
 		for _, subset := range endpoints.Subsets {
 			for _, address := range subset.Addresses {
 				if address.Hostname == "" {
@@ -498,8 +503,13 @@ func (v *EnvoyConfigVerifier) getDstMeshServicesForSvcPod(svc corev1.Service, po
 					Protocol:   meshSvc.Protocol,
 				}
 				meshServices = append(meshServices, mSvc)
+				added = true
 			}
 		}
+
+		if !added {
+			meshServices = append(meshServices, meshSvc)
+		}
 	}
 
 	return meshServices, nil

pkg/k8s/client.go

@@ -322,7 +322,9 @@ func ServiceToMeshServices(c Controller, svc corev1.Service) []service.MeshServi
 			meshServices = append(meshServices, meshSvc)
 			continue
 		}
-
+		// If there's not at least 1 subdomain-ed MeshService added,
+		// add the entire headless service
+		var added bool
 		for _, subset := range endpoints.Subsets {
 			for _, address := range subset.Addresses {
 				if address.Hostname == "" {
@@ -335,10 +337,14 @@ func ServiceToMeshServices(c Controller, svc corev1.Service) []service.MeshServi
 					TargetPort: meshSvc.TargetPort,
 					Protocol:   meshSvc.Protocol,
 				})
+				added = true
 			}
 		}
-	}
 
+		if !added {
+			meshServices = append(meshServices, meshSvc)
+		}
+	}
 	return meshServices
 }
 

pkg/k8s/client_test.go

@@ -880,6 +880,61 @@ func TestK8sServicesToMeshServices(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "k8s headless service with single port and endpoint (no hostname), no appProtocol set",
+			// Single port on the service maps to a single MeshService.
+			// Since no appProtocol is specified, MeshService.Protocol should default
+			// to http because Port.Protocol=TCP
+			svc: corev1.Service{
+				ObjectMeta: metav1.ObjectMeta{
+					Namespace: "ns1",
+					Name:      "s1",
+				},
+				Spec: corev1.ServiceSpec{
+					Ports: []corev1.ServicePort{
+						{
+							Name:     "p1",
+							Port:     80,
+							Protocol: corev1.ProtocolTCP,
+						},
+					},
+					ClusterIP: corev1.ClusterIPNone,
+				},
+			},
+			svcEndpoints: []runtime.Object{
+				&corev1.Endpoints{
+					ObjectMeta: metav1.ObjectMeta{
+						// Should match svc.Name and svc.Namespace
+						Namespace: "ns1",
+						Name:      "s1",
+					},
+					Subsets: []corev1.EndpointSubset{
+						{
+							Addresses: []corev1.EndpointAddress{
+								{
+									IP: "10.1.0.1",
+								},
+							},
+							Ports: []corev1.EndpointPort{
+								{
+									// Must match the port of 'svc.Spec.Ports[0]'
+									Port: 8080, // TargetPort
+								},
+							},
+						},
+					},
+				},
+			},
+			expected: []service.MeshService{
+				{
+					Namespace:  "ns1",
+					Name:       "s1",
+					Port:       80,
+					TargetPort: 8080,
+					Protocol:   "http",
+				},
+			},
+		},
 		{
 			name: "multiple ports on k8s service with appProtocol specified",
 			svc: corev1.Service{

tests/e2e/e2e_client_server_connectivity_test.go

@@ -12,6 +12,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/openservicemesh/osm/pkg/apis/config/v1alpha2"
+	"github.com/openservicemesh/osm/pkg/tests"
 
 	"github.com/openservicemesh/osm/pkg/constants"
 	. "github.com/openservicemesh/osm/tests/framework"
@@ -26,26 +27,34 @@ var _ = OSMDescribe("Test HTTP traffic from 1 pod client -> 1 pod server",
 	func() {
 		Context("Test traffic flowing from client to server with a Kubernetes Service for the Source: HTTP", func() {
 			withSourceKubernetesService := true
-			testTraffic(withSourceKubernetesService, PodCommandDefault)
+			testTraffic(withSourceKubernetesService, PodCommandDefault, false)
 		})
 
 		Context("Test traffic flowing from client to server without a Kubernetes Service for the Source: HTTP", func() {
 			// Prior iterations of OSM required that a source pod belong to a Kubernetes service
 			// for the Envoy proxy to be configured for outbound traffic to some remote server.
 			// This test ensures we test this scenario: client Pod is not associated w/ a service.
 			withSourceKubernetesService := false
-			testTraffic(withSourceKubernetesService, PodCommandDefault)
+			testTraffic(withSourceKubernetesService, PodCommandDefault, false)
 		})
 
 		Context("Test traffic flowing from client to a server with a podIP bind", func() {
 			// Prior iterations of OSM didn't allow mesh services to bind to the podIP
 			// This test ensures that that behavior is configurable via MeshConfig
 			withSourceKubernetesService := true
-			testTraffic(withSourceKubernetesService, []string{"gunicorn", "-b", "$(POD_IP):80", "httpbin:app", "-k", "gevent"}, WithLocalProxyMode(v1alpha2.LocalProxyModePodIP))
+			testTraffic(withSourceKubernetesService, []string{"gunicorn", "-b", "$(POD_IP):80", "httpbin:app", "-k", "gevent"}, false, WithLocalProxyMode(v1alpha2.LocalProxyModePodIP))
+		})
+
+		Context("Test traffic flowing from client to a headless service without a Kubernetes Service for the Source: HTTP", func() {
+			// Prior iterations of OSM required that a source pod belong to a Kubernetes service
+			// for the Envoy proxy to be configured for outbound traffic to some remote server.
+			// This test ensures we test this scenario: client Pod is not associated w/ a service.
+			withSourceKubernetesService := true
+			testTraffic(withSourceKubernetesService, PodCommandDefault, true)
 		})
 	})
 
-func testTraffic(withSourceKubernetesService bool, destPodCommand []string, installOpts ...InstallOsmOpt) {
+func testTraffic(withSourceKubernetesService bool, destPodCommand []string, destServiceHeadless bool, installOpts ...InstallOsmOpt) {
 	const sourceName = "client"
 	const destName = "server"
 	var ns = []string{sourceName, destName}
@@ -68,7 +77,7 @@ func testTraffic(withSourceKubernetesService bool, destPodCommand []string, inst
 		Expect(err).NotTo(HaveOccurred())
 		_, err = Td.CreatePod(destName, podDef)
 		Expect(err).NotTo(HaveOccurred())
-		dstSvc, err := Td.CreateService(destName, svcDef)
+		dstSvc, err := Td.CreateService(destName, *tests.HeadlessSvc(&svcDef))
 		Expect(err).NotTo(HaveOccurred())
 
 		// Expect it to be up and running in it's receiver namespace