Fix SRV records not returned for clusterset IP service

With clusterset IP enabled, we extract the ports from the
aggregated ServiceImport instead of the EndpointSlices.
However the ports are populated in the ServiceImport sometime
after creation so PutServiceImport needs to update the
cached spec if it already exists.

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

coredns/resolver/clusterip_service_test.go

@@ -450,9 +450,13 @@ func testClusterSetIP() {
 
 	BeforeEach(func() {
 		si := newAggregatedServiceImport(namespace1, service1)
+
 		si.Spec.IPs = []string{clusterSetIP}
-		si.Spec.Ports = []mcsv1a1.ServicePort{port1, port2}
+		t.resolver.PutServiceImport(si)
 
+		// We call PutServiceImport separately with the ports to ensure it updates the cache. This simulates the
+		// real behavior where the port information is added/updated in the ServiceImport some time after creation.
+		si.Spec.Ports = []mcsv1a1.ServicePort{port1, port2}
 		t.resolver.PutServiceImport(si)
 
 		t.putEndpointSlice(newClusterIPEndpointSlice(namespace1, service1, clusterID1, serviceIP1, true, port1))

coredns/resolver/service_import.go

@@ -43,13 +43,13 @@ func (i *Interface) PutServiceImport(serviceImport *mcsv1a1.ServiceImport) {
 			balancer: loadbalancer.NewSmoothWeightedRR(),
 		}
 
-		if !isLegacy {
-			svcInfo.spec = serviceImport.Spec
-		}
-
 		i.serviceMap[key] = svcInfo
 	}
 
+	if !isLegacy {
+		svcInfo.spec = serviceImport.Spec
+	}
+
 	svcInfo.isExported = true
 
 	if svcInfo.isHeadless() || !isLegacy {