Updating Topology Aware Hints to support "Auto" value for annotation

Previously only "auto" was supported, a value that was inconsistent with
Kubernetes naming patterns.

pkg/controller/endpointslice/metrics/metrics.go

@@ -102,7 +102,7 @@ var (
 			Name:      "endpointslices_changed_per_sync",
 			Help:      "Number of EndpointSlices changed on each Service sync",
 		},
-		[]string{"topology"}, // either "auto" or "disabled"
+		[]string{"topology"}, // either "Auto" or "Disabled"
 	)
 
 	// EndpointSliceSyncs tracks the number of sync operations the controller

pkg/controller/endpointslice/reconciler.go

@@ -330,9 +330,9 @@ func (r *reconciler) finalize(
 		metrics.EndpointSliceChanges.WithLabelValues("delete").Inc()
 	}
 
-	topologyLabel := "disabled"
+	topologyLabel := "Disabled"
 	if r.topologyCache != nil && hintsEnabled(service.Annotations) {
-		topologyLabel = "auto"
+		topologyLabel = "Auto"
 	}
 
 	numSlicesChanged := len(slicesToCreate) + len(slicesToUpdate) + len(slicesToDelete)

pkg/controller/endpointslice/reconciler_test.go

@@ -1460,9 +1460,9 @@ func TestReconcileTopology(t *testing.T) {
 			slicesChangedPerSyncTopology: 0,
 		},
 	}, {
-		name:                 "topology enabled, hintsAnnotation==auto, more slices and endpoints",
+		name:                 "topology enabled, hintsAnnotation==Auto, more slices and endpoints",
 		topologyCacheEnabled: true,
-		hintsAnnotation:      "auto",
+		hintsAnnotation:      "Auto",
 		existingSlices:       []*discovery.EndpointSlice{slicesByName["zone-a-c"], slicesByName["zone-a-b"]},
 		pods:                 append(slicePods["zone-a-c"], slicePods["zone-a-b"]...),
 		nodes:                nodes,
@@ -1784,13 +1784,13 @@ func expectMetrics(t *testing.T, em expectedMetrics) {
 		t.Errorf("Expected endpointSliceChangesDeleted to be %d, got %v", em.numDeleted, actualDeleted)
 	}
 
-	actualSlicesChangedPerSync, err := testutil.GetHistogramMetricValue(metrics.EndpointSlicesChangedPerSync.WithLabelValues("disabled"))
+	actualSlicesChangedPerSync, err := testutil.GetHistogramMetricValue(metrics.EndpointSlicesChangedPerSync.WithLabelValues("Disabled"))
 	handleErr(t, err, "slicesChangedPerSync")
 	if actualSlicesChangedPerSync != float64(em.slicesChangedPerSync) {
 		t.Errorf("Expected slicesChangedPerSync to be %d, got %v", em.slicesChangedPerSync, actualSlicesChangedPerSync)
 	}
 
-	actualSlicesChangedPerSyncTopology, err := testutil.GetHistogramMetricValue(metrics.EndpointSlicesChangedPerSync.WithLabelValues("auto"))
+	actualSlicesChangedPerSyncTopology, err := testutil.GetHistogramMetricValue(metrics.EndpointSlicesChangedPerSync.WithLabelValues("Auto"))
 	handleErr(t, err, "slicesChangedPerSyncTopology")
 	if actualSlicesChangedPerSyncTopology != float64(em.slicesChangedPerSyncTopology) {
 		t.Errorf("Expected slicesChangedPerSyncTopology to be %d, got %v", em.slicesChangedPerSyncTopology, actualSlicesChangedPerSyncTopology)
@@ -1825,8 +1825,8 @@ func setupMetrics() {
 	metrics.EndpointSliceChanges.Delete(map[string]string{"operation": "create"})
 	metrics.EndpointSliceChanges.Delete(map[string]string{"operation": "update"})
 	metrics.EndpointSliceChanges.Delete(map[string]string{"operation": "delete"})
-	metrics.EndpointSlicesChangedPerSync.Delete(map[string]string{"topology": "disabled"})
-	metrics.EndpointSlicesChangedPerSync.Delete(map[string]string{"topology": "auto"})
+	metrics.EndpointSlicesChangedPerSync.Delete(map[string]string{"topology": "Disabled"})
+	metrics.EndpointSlicesChangedPerSync.Delete(map[string]string{"topology": "Auto"})
 	metrics.EndpointSliceSyncs.Delete(map[string]string{"result": "success"})
 	metrics.EndpointSliceSyncs.Delete(map[string]string{"result": "error"})
 }

pkg/controller/endpointslice/utils.go

@@ -386,11 +386,11 @@ func unchangedSlices(existingSlices, slicesToUpdate, slicesToDelete []*discovery
 }
 
 // hintsEnabled returns true if the provided annotations include a
-// corev1.AnnotationTopologyAwareHints key with a value set to "auto".
+// corev1.AnnotationTopologyAwareHints key with a value set to "Auto" or "auto".
 func hintsEnabled(annotations map[string]string) bool {
 	val, ok := annotations[corev1.AnnotationTopologyAwareHints]
 	if !ok {
 		return false
 	}
-	return val == "auto"
+	return val == "Auto" || val == "auto"
 }

pkg/controller/endpointslice/utils_test.go

@@ -1165,3 +1165,46 @@ func TestSupportedServiceAddressType(t *testing.T) {
 		})
 	}
 }
+
+func Test_hintsEnabled(t *testing.T) {
+	testCases := []struct {
+		name          string
+		annotations   map[string]string
+		expectEnabled bool
+	}{{
+		name:          "empty annotations",
+		expectEnabled: false,
+	}, {
+		name:          "different annotations",
+		annotations:   map[string]string{"topology-hints": "enabled"},
+		expectEnabled: false,
+	}, {
+		name:          "annotation == enabled",
+		annotations:   map[string]string{v1.AnnotationTopologyAwareHints: "enabled"},
+		expectEnabled: false,
+	}, {
+		name:          "annotation == aUto",
+		annotations:   map[string]string{v1.AnnotationTopologyAwareHints: "aUto"},
+		expectEnabled: false,
+	}, {
+		name:          "annotation == auto",
+		annotations:   map[string]string{v1.AnnotationTopologyAwareHints: "auto"},
+		expectEnabled: true,
+	}, {
+		name:          "annotation == Auto",
+		annotations:   map[string]string{v1.AnnotationTopologyAwareHints: "Auto"},
+		expectEnabled: true,
+	}, {
+		name:          "annotation == disabled",
+		annotations:   map[string]string{v1.AnnotationTopologyAwareHints: "disabled"},
+		expectEnabled: false,
+	}}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actualEnabled := hintsEnabled(tc.annotations)
+			if actualEnabled != tc.expectEnabled {
+				t.Errorf("Expected %t, got %t", tc.expectEnabled, actualEnabled)
+			}
+		})
+	}
+}