topology-updater: Refactor Scan to expand response

We are gonna add new data to Scan response so better introduce a new
ScanResponse struct as Scan return value to make it easier.

pkg/nfd-topology-updater/nfd-topology-updater.go

@@ -154,13 +154,13 @@ func (w *nfdTopologyUpdater) Run() error {
 		select {
 		case <-crTrigger.C:
 			klog.Infof("Scanning")
-			podResources, err := resScan.Scan()
+			scanResponse, err := resScan.Scan()
-			utils.KlogDump(1, "podResources are", "  ", podResources)
+			utils.KlogDump(1, "podResources are", "  ", scanResponse.PodResources)
 			if err != nil {
 				klog.Warningf("Scan failed: %v", err)
 				continue
 			}
-			zones = resAggr.Aggregate(podResources)
+			zones = resAggr.Aggregate(scanResponse.PodResources)
 			utils.KlogDump(1, "After aggregating resources identified zones are", "  ", zones)
 			if !w.args.NoPublish {
 				if err = w.updateNodeResourceTopology(zones); err != nil {

pkg/resourcemonitor/podresourcesscanner.go

@@ -113,14 +113,14 @@ func hasIntegralCPUs(pod *corev1.Pod, container *corev1.Container) bool {
 }
 
 // Scan gathers all the PodResources from the system, using the podresources API client.
-func (resMon *PodResourcesScanner) Scan() ([]PodResources, error) {
+func (resMon *PodResourcesScanner) Scan() (ScanResponse, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultPodResourcesTimeout)
 	defer cancel()
 
 	// Pod Resource API client
 	resp, err := resMon.podResourceClient.List(ctx, &podresourcesapi.ListPodResourcesRequest{})
 	if err != nil {
-		return nil, fmt.Errorf("can't receive response: %v.Get(_) = _, %w", resMon.podResourceClient, err)
+		return ScanResponse{}, fmt.Errorf("can't receive response: %v.Get(_) = _, %w", resMon.podResourceClient, err)
 	}
 
 	var podResData []PodResources
@@ -130,7 +130,7 @@ func (resMon *PodResourcesScanner) Scan() ([]PodResources, error) {
 		hasDevice := hasDevice(podResource)
 		isWatchable, isIntegralGuaranteed, err := resMon.isWatchable(podResource.GetNamespace(), podResource.GetName(), hasDevice)
 		if err != nil {
-			return nil, fmt.Errorf("checking if pod in a namespace is watchable, namespace:%v, pod name %v: %v", podResource.GetNamespace(), podResource.GetName(), err)
+			return ScanResponse{}, fmt.Errorf("checking if pod in a namespace is watchable, namespace:%v, pod name %v: %v", podResource.GetNamespace(), podResource.GetName(), err)
 		}
 		if !isWatchable {
 			continue
@@ -198,7 +198,7 @@ func (resMon *PodResourcesScanner) Scan() ([]PodResources, error) {
 
 	}
 
-	return podResData, nil
+	return ScanResponse{PodResources: podResData}, nil
 }
 
 func hasDevice(podResource *podresourcesapi.PodResources) bool {

pkg/resourcemonitor/podresourcesscanner_test.go

@@ -58,7 +58,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldNotBeNil)
 			})
 			Convey("Return PodResources should be nil", func() {
-				So(res, ShouldBeNil)
+				So(res.PodResources, ShouldBeNil)
 			})
 		})
 
@@ -70,7 +70,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should be zero", func() {
-				So(len(res), ShouldEqual, 0)
+				So(len(res.PodResources), ShouldEqual, 0)
 			})
 		})
 
@@ -160,7 +160,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 
 				expected := []PodResources{
 					{
@@ -194,14 +194,14 @@ func TestPodScanner(t *testing.T) {
 						},
 					},
 				}
-				for _, podresource := range res {
+				for _, podresource := range res.PodResources {
 					for _, container := range podresource.Containers {
-						sort.Slice(res, func(i, j int) bool {
+						sort.Slice(res.PodResources, func(i, j int) bool {
 							return container.Resources[i].Name < container.Resources[j].Name
 						})
 					}
 				}
-				So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+				So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 			})
 		})
 
@@ -266,7 +266,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 
 				expected := []PodResources{
 					{
@@ -290,7 +290,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				}
 
-				So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+				So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 			})
 		})
 
@@ -345,7 +345,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 
 				expected := []PodResources{
 					{
@@ -365,7 +365,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				}
 
-				So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+				So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 			})
 		})
 
@@ -427,7 +427,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 
 				expected := []PodResources{
 					{
@@ -447,7 +447,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				}
 
-				So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+				So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 			})
 		})
 
@@ -505,7 +505,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 			})
 
 			expected := []PodResources{
@@ -526,7 +526,7 @@ func TestPodScanner(t *testing.T) {
 				},
 			}
 
-			So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+			So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 		})
 
 		Convey("When I successfully get valid response for (non-guaranteed) pods with devices with cpus", func() {
@@ -589,7 +589,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 			})
 
 			expected := []PodResources{
@@ -609,7 +609,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				},
 			}
-			So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+			So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 		})
 
 	})
@@ -632,7 +632,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldNotBeNil)
 			})
 			Convey("Return PodResources should be nil", func() {
-				So(res, ShouldBeNil)
+				So(res.PodResources, ShouldBeNil)
 			})
 		})
 
@@ -644,7 +644,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should be zero", func() {
-				So(len(res), ShouldEqual, 0)
+				So(len(res.PodResources), ShouldEqual, 0)
 			})
 		})
 
@@ -712,7 +712,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should be zero", func() {
-				So(len(res), ShouldEqual, 0)
+				So(len(res.PodResources), ShouldEqual, 0)
 			})
 		})
 
@@ -778,7 +778,7 @@ func TestPodScanner(t *testing.T) {
 			})
 
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 
 				expected := []PodResources{
 					{
@@ -802,7 +802,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				}
 
-				So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+				So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 			})
 		})
 
@@ -858,7 +858,7 @@ func TestPodScanner(t *testing.T) {
 			})
 			Convey("Return PodResources should have values", func() {
 				Convey("Return PodResources should be zero", func() {
-					So(len(res), ShouldEqual, 0)
+					So(len(res.PodResources), ShouldEqual, 0)
 				})
 			})
 		})
@@ -923,7 +923,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldEqual, 0)
+				So(len(res.PodResources), ShouldEqual, 0)
 			})
 		})
 
@@ -981,7 +981,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 			})
 
 			expected := []PodResources{
@@ -1002,7 +1002,7 @@ func TestPodScanner(t *testing.T) {
 				},
 			}
 
-			So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+			So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 		})
 
 		Convey("When I successfully get valid response for (non-guaranteed) pods with devices with cpus", func() {
@@ -1065,7 +1065,7 @@ func TestPodScanner(t *testing.T) {
 				So(err, ShouldBeNil)
 			})
 			Convey("Return PodResources should have values", func() {
-				So(len(res), ShouldBeGreaterThan, 0)
+				So(len(res.PodResources), ShouldBeGreaterThan, 0)
 			})
 
 			expected := []PodResources{
@@ -1085,7 +1085,7 @@ func TestPodScanner(t *testing.T) {
 					},
 				},
 			}
-			So(reflect.DeepEqual(res, expected), ShouldBeTrue)
+			So(reflect.DeepEqual(res.PodResources, expected), ShouldBeTrue)
 		})
 
 	})

pkg/resourcemonitor/types.go

@@ -53,9 +53,13 @@ type PodResources struct {
 	Containers []ContainerResources
 }
 
+type ScanResponse struct {
+	PodResources []PodResources
+}
+
 // ResourcesScanner gathers all the PodResources from the system, using the podresources API client
 type ResourcesScanner interface {
-	Scan() ([]PodResources, error)
+	Scan() (ScanResponse, error)
 }
 
 // ResourcesAggregator aggregates resource information based on the received data from underlying hardware and podresource API