Resource manager: add service lister and remove unused lock. (#559)

* Remove unused lock from the resource manager.

* Add service lister to the resource manager.

This change adds a service lister in the
resource manager.
This will be used to set the service env vars.
Also added a List method to the resource manager
and a simple test to confirm it's a pass through.

manager/resource.go

@@ -1,8 +1,6 @@
 package manager
 
 import (
-	"sync"
-
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	corev1listers "k8s.io/client-go/listers/core/v1"
@@ -13,19 +11,19 @@ import (
 // ResourceManager acts as a passthrough to a cache (lister) for pods assigned to the current node.
 // It is also a passthrough to a cache (lister) for Kubernetes secrets and config maps.
 type ResourceManager struct {
-	sync.RWMutex
-
 	podLister       corev1listers.PodLister
 	secretLister    corev1listers.SecretLister
 	configMapLister corev1listers.ConfigMapLister
+	serviceLister   corev1listers.ServiceLister
 }
 
 // NewResourceManager returns a ResourceManager with the internal maps initialized.
-func NewResourceManager(podLister corev1listers.PodLister, secretLister corev1listers.SecretLister, configMapLister corev1listers.ConfigMapLister) (*ResourceManager, error) {
+func NewResourceManager(podLister corev1listers.PodLister, secretLister corev1listers.SecretLister, configMapLister corev1listers.ConfigMapLister, serviceLister corev1listers.ServiceLister) (*ResourceManager, error) {
 	rm := ResourceManager{
 		podLister:       podLister,
 		secretLister:    secretLister,
 		configMapLister: configMapLister,
+		serviceLister:   serviceLister,
 	}
 	return &rm, nil
 }
@@ -49,3 +47,8 @@ func (rm *ResourceManager) GetConfigMap(name, namespace string) (*v1.ConfigMap,
 func (rm *ResourceManager) GetSecret(name, namespace string) (*v1.Secret, error) {
 	return rm.secretLister.Secrets(namespace).Get(name)
 }
+
+// ListServices retrieves the list of services from Kubernetes.
+func (rm *ResourceManager) ListServices() ([]*v1.Service, error) {
+	return rm.serviceLister.List(labels.Everything())
+}

manager/resource_test.go

@@ -29,7 +29,7 @@ func TestGetPods(t *testing.T) {
 	podLister := corev1listers.NewPodLister(indexer)
 
 	// Create a new instance of the resource manager based on the pod lister.
-	rm, err := manager.NewResourceManager(podLister, nil, nil)
+	rm, err := manager.NewResourceManager(podLister, nil, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -58,7 +58,7 @@ func TestGetSecret(t *testing.T) {
 	secretLister := corev1listers.NewSecretLister(indexer)
 
 	// Create a new instance of the resource manager based on the secret lister.
-	rm, err := manager.NewResourceManager(nil, secretLister, nil)
+	rm, err := manager.NewResourceManager(nil, secretLister, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -97,7 +97,7 @@ func TestGetConfigMap(t *testing.T) {
 	configMapLister := corev1listers.NewConfigMapLister(indexer)
 
 	// Create a new instance of the resource manager based on the config map lister.
-	rm, err := manager.NewResourceManager(nil, nil, configMapLister)
+	rm, err := manager.NewResourceManager(nil, nil, configMapLister, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -118,3 +118,35 @@ func TestGetConfigMap(t *testing.T) {
 		t.Fatalf("expected a 'not found' error, got %v", err)
 	}
 }
+
+// TestListServices verifies that the resource manager acts as a passthrough to a service lister.
+func TestListServices(t *testing.T) {
+	var (
+		lsServices = []*v1.Service{
+			testutil.FakeService("namespace-0", "service-0"),
+			testutil.FakeService("namespace-1", "service-1"),
+		}
+	)
+
+	// Create a pod lister that will list the pods defined above.
+	indexer := cache.NewIndexer(cache.MetaNamespaceKeyFunc, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
+	for _, service := range lsServices {
+		indexer.Add(service)
+	}
+	serviceLister := corev1listers.NewServiceLister(indexer)
+
+	// Create a new instance of the resource manager based on the pod lister.
+	rm, err := manager.NewResourceManager(nil, nil, nil, serviceLister)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Check that the resource manager returns two pods in the call to "GetPods".
+	services, err := rm.ListServices()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(lsServices) != len(services) {
+		t.Fatalf("expected %d services, found %d", len(lsServices), len(services))
+	}
+}