topology-gc: refactor unit tests

Remove a lot of boilerplate code by defining reusable functions.

Also, test the Run() method instead of the functions callees of Run() as
it is the top level functionality that was tested in practice (we don't
have separate unit tests for the callee functions).

pkg/nfd-topology-gc/nfd-nrt-gc_test.go

@@ -22,10 +22,14 @@ import (
 	"time"
 
 	"github.com/k8stopologyawareschedwg/noderesourcetopology-api/pkg/apis/topology/v1alpha2"
+	topologyclientset "github.com/k8stopologyawareschedwg/noderesourcetopology-api/pkg/generated/clientset/versioned"
 	faketopologyv1alpha2 "github.com/k8stopologyawareschedwg/noderesourcetopology-api/pkg/generated/clientset/versioned/fake"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/informers"
+	k8sclientset "k8s.io/client-go/kubernetes"
 	fakek8sclientset "k8s.io/client-go/kubernetes/fake"
 
 	. "github.com/smartystreets/goconvey/convey"
@@ -33,177 +37,42 @@ import (
 
 func TestNRTGC(t *testing.T) {
 	Convey("When theres is old NRT ", t, func() {
-		k8sClient := fakek8sclientset.NewSimpleClientset()
+		gc := newMockGC(nil, []string{"node1"})
 
-		fakeClient := faketopologyv1alpha2.NewSimpleClientset(&v1alpha2.NodeResourceTopology{
+		errChan := make(chan error, 1)
-			ObjectMeta: metav1.ObjectMeta{
+		go func() { errChan <- gc.Run() }()
-				Name: "node1",
-			},
-		})
-		factory := informers.NewSharedInformerFactory(k8sClient, 5*time.Minute)
 
-		stopChan := make(chan struct{}, 1)
+		So(waitForNRT(gc.topoClient), ShouldBeTrue)
-
-		gc := &topologyGC{
-			factory:    factory,
-			topoClient: fakeClient,
-			stopChan:   stopChan,
-			gcPeriod:   10 * time.Minute,
-		}
-
-		err := gc.startNodeInformer()
-		So(err, ShouldBeNil)
-
-		nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
-		So(err, ShouldBeNil)
-		So(nrts.Items, ShouldHaveLength, 0)
 
 		gc.Stop()
+		So(<-errChan, ShouldBeNil)
 	})
 	Convey("When theres is one old NRT and one up to date", t, func() {
-		k8sClient := fakek8sclientset.NewSimpleClientset(&corev1.Node{
+		gc := newMockGC([]string{"node1"}, []string{"node1", "node2"})
-			ObjectMeta: metav1.ObjectMeta{
-				Name: "node1",
-			},
-		})
 
-		fakeClient := faketopologyv1alpha2.NewSimpleClientset(&v1alpha2.NodeResourceTopology{
+		errChan := make(chan error, 1)
-			ObjectMeta: metav1.ObjectMeta{
+		go func() { errChan <- gc.Run() }()
-				Name: "node1",
-			},
-		},
-			&v1alpha2.NodeResourceTopology{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node2",
-				},
-			},
-		)
 
-		stopChan := make(chan struct{}, 1)
+		So(waitForNRT(gc.topoClient, "node1"), ShouldBeTrue)
-
-		factory := informers.NewSharedInformerFactory(k8sClient, 5*time.Minute)
-
-		gc := &topologyGC{
-			factory:    factory,
-			topoClient: fakeClient,
-			stopChan:   stopChan,
-			gcPeriod:   10 * time.Minute,
-		}
-
-		err := gc.startNodeInformer()
-		So(err, ShouldBeNil)
-
-		nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
-		So(err, ShouldBeNil)
-		So(nrts.Items, ShouldHaveLength, 1)
-		So(nrts.Items[0].GetName(), ShouldEqual, "node1")
 
+		gc.Stop()
+		So(<-errChan, ShouldBeNil)
 	})
 	Convey("Should react to delete event", t, func() {
-		k8sClient := fakek8sclientset.NewSimpleClientset(
+		gc := newMockGC([]string{"node1", "node2"}, []string{"node1", "node2"})
-			&corev1.Node{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node1",
-				},
-			},
-			&corev1.Node{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node2",
-				},
-			},
-		)
 
-		fakeClient := faketopologyv1alpha2.NewSimpleClientset(
+		errChan := make(chan error, 1)
-			&v1alpha2.NodeResourceTopology{
+		go func() { errChan <- gc.Run() }()
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node1",
-				},
-			},
-			&v1alpha2.NodeResourceTopology{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node2",
-				},
-			},
-		)
 
-		stopChan := make(chan struct{}, 1)
+		err := gc.k8sClient.CoreV1().Nodes().Delete(context.TODO(), "node1", metav1.DeleteOptions{})
-
-		factory := informers.NewSharedInformerFactory(k8sClient, 5*time.Minute)
-		gc := &topologyGC{
-			factory:    factory,
-			topoClient: fakeClient,
-			stopChan:   stopChan,
-			gcPeriod:   10 * time.Minute,
-		}
-
-		err := gc.startNodeInformer()
 		So(err, ShouldBeNil)
 
-		nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
+		So(waitForNRT(gc.topoClient, "node2"), ShouldBeTrue)
-		So(err, ShouldBeNil)
-
-		So(nrts.Items, ShouldHaveLength, 2)
-
-		err = k8sClient.CoreV1().Nodes().Delete(context.TODO(), "node1", metav1.DeleteOptions{})
-		So(err, ShouldBeNil)
-		// simple sleep with retry loop to make sure indexer will pick up event and trigger deleteNode Function
-		deleted := false
-		for i := 0; i < 5; i++ {
-			nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
-			So(err, ShouldBeNil)
-
-			if len(nrts.Items) == 1 {
-				deleted = true
-				break
-			}
-			time.Sleep(time.Second)
-		}
-		So(deleted, ShouldBeTrue)
 	})
 	Convey("periodic GC should remove obsolete NRT", t, func() {
-		k8sClient := fakek8sclientset.NewSimpleClientset(
+		gc := newMockGC([]string{"node1", "node2"}, []string{"node1", "node2"})
-			&corev1.Node{
+		// Override period to run fast
-				ObjectMeta: metav1.ObjectMeta{
+		gc.gcPeriod = 100 * time.Millisecond
-					Name: "node1",
-				},
-			},
-			&corev1.Node{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node2",
-				},
-			},
-		)
-
-		fakeClient := faketopologyv1alpha2.NewSimpleClientset(
-			&v1alpha2.NodeResourceTopology{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node1",
-				},
-			},
-			&v1alpha2.NodeResourceTopology{
-				ObjectMeta: metav1.ObjectMeta{
-					Name: "node2",
-				},
-			},
-		)
-
-		stopChan := make(chan struct{}, 1)
-
-		factory := informers.NewSharedInformerFactory(k8sClient, 5*time.Minute)
-		gc := &topologyGC{
-			factory:    factory,
-			topoClient: fakeClient,
-			stopChan:   stopChan,
-			gcPeriod:   time.Second,
-		}
-
-		err := gc.startNodeInformer()
-		So(err, ShouldBeNil)
-
-		nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
-		So(err, ShouldBeNil)
-
-		So(nrts.Items, ShouldHaveLength, 2)
 
 		nrt := v1alpha2.NodeResourceTopology{
 			ObjectMeta: metav1.ObjectMeta{
@@ -211,23 +80,72 @@ func TestNRTGC(t *testing.T) {
 			},
 		}
 
-		go gc.periodicGC(time.Second)
+		errChan := make(chan error, 1)
+		go func() { errChan <- gc.Run() }()
 
-		_, err = fakeClient.TopologyV1alpha2().NodeResourceTopologies().Create(context.TODO(), &nrt, metav1.CreateOptions{})
+		_, err := gc.topoClient.TopologyV1alpha2().NodeResourceTopologies().Create(context.TODO(), &nrt, metav1.CreateOptions{})
 		So(err, ShouldBeNil)
-		// simple sleep with retry loop to make sure GC was triggered
-		deleted := false
-		for i := 0; i < 5; i++ {
-			nrts, err := fakeClient.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
-			So(err, ShouldBeNil)
 
-			if len(nrts.Items) == 2 {
+		So(waitForNRT(gc.topoClient, "node1", "node2"), ShouldBeTrue)
-				deleted = true
-				break
-			}
-			time.Sleep(2 * time.Second)
-		}
-		So(deleted, ShouldBeTrue)
 	})
-
+}
+
+func newMockGC(nodes, nrts []string) *mockGC {
+	k8sClient := fakek8sclientset.NewSimpleClientset(createFakeNodes(nodes...)...)
+	return &mockGC{
+		topologyGC: topologyGC{
+			factory:    informers.NewSharedInformerFactory(k8sClient, 5*time.Minute),
+			topoClient: faketopologyv1alpha2.NewSimpleClientset(createFakeNRTs(nrts...)...),
+			stopChan:   make(chan struct{}, 1),
+			gcPeriod:   10 * time.Minute,
+		},
+		k8sClient: k8sClient,
+	}
+}
+
+func createFakeNodes(names ...string) []runtime.Object {
+	nodes := make([]runtime.Object, len(names))
+	for i, n := range names {
+		nodes[i] = &corev1.Node{
+			ObjectMeta: metav1.ObjectMeta{
+				Name: n,
+			}}
+	}
+	return nodes
+}
+
+func createFakeNRTs(names ...string) []runtime.Object {
+	nrts := make([]runtime.Object, len(names))
+	for i, n := range names {
+		nrts[i] = &v1alpha2.NodeResourceTopology{
+			ObjectMeta: metav1.ObjectMeta{
+				Name: n,
+			}}
+	}
+	return nrts
+}
+
+type mockGC struct {
+	topologyGC
+
+	k8sClient k8sclientset.Interface
+}
+
+func waitForNRT(cli topologyclientset.Interface, names ...string) bool {
+	nameSet := sets.NewString(names...)
+	for i := 0; i < 2; i++ {
+		nrts, err := cli.TopologyV1alpha2().NodeResourceTopologies().List(context.TODO(), metav1.ListOptions{})
+		So(err, ShouldBeNil)
+
+		nrtNames := sets.NewString()
+		for _, nrt := range nrts.Items {
+			nrtNames.Insert(nrt.Name)
+		}
+
+		if nrtNames.Equal(nameSet) {
+			return true
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return false
 }