Cleanup: remove prometheus dependencies for volume

Co-authored-by: gavinfish <drfish.me@gmail.com>

hack/verify-prometheus-imports.sh

@@ -37,7 +37,6 @@ source "${KUBE_ROOT}/hack/lib/util.sh"
 # See: https://github.com/kubernetes/kubernetes/issues/89267
 allowed_prometheus_importers=(
   ./cluster/images/etcd-version-monitor/etcd-version-monitor.go
-  ./pkg/volume/util/operationexecutor/operation_generator_test.go
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/timing_histogram.go
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/timing_histogram_test.go
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/timing_histogram_vec.go

pkg/volume/util/metrics.go

@@ -44,7 +44,8 @@ const (
  * involves explicitly acknowledging support for the metric across multiple releases, in accordance with
  * the metric stability policy.
  */
-var storageOperationMetric = metrics.NewHistogramVec(
+
+var StorageOperationMetric = metrics.NewHistogramVec(
 	&metrics.HistogramOpts{
 		Name:           "storage_operation_duration_seconds",
 		Help:           "Storage operation duration",
@@ -82,7 +83,7 @@ func init() {
 func registerMetrics() {
 	// legacyregistry is the internal k8s wrapper around the prometheus
 	// global registry, used specifically for metric stability enforcement
-	legacyregistry.MustRegister(storageOperationMetric)
+	legacyregistry.MustRegister(StorageOperationMetric)
 	legacyregistry.MustRegister(storageOperationEndToEndLatencyMetric)
 	legacyregistry.MustRegister(csiOperationsLatencyMetric)
 }
@@ -103,7 +104,7 @@ func OperationCompleteHook(plugin, operationName string) func(types.CompleteFunc
 		if c.Migrated != nil {
 			migrated = *c.Migrated
 		}
-		storageOperationMetric.WithLabelValues(plugin, operationName, status, strconv.FormatBool(migrated)).Observe(timeTaken)
+		StorageOperationMetric.WithLabelValues(plugin, operationName, status, strconv.FormatBool(migrated)).Observe(timeTaken)
 	}
 	return opComplete
 }

pkg/volume/util/operationexecutor/operation_generator_test.go

@@ -28,20 +28,20 @@ import (
 	"os"
 	"testing"
 
-	io_prometheus_client "github.com/prometheus/client_model/go"
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/uuid"
 	fakeclient "k8s.io/client-go/kubernetes/fake"
-	"k8s.io/component-base/metrics/legacyregistry"
+	"k8s.io/component-base/metrics/testutil"
 	"k8s.io/csi-translation-lib/plugins"
 	"k8s.io/kubernetes/pkg/volume"
 	"k8s.io/kubernetes/pkg/volume/awsebs"
 	csitesting "k8s.io/kubernetes/pkg/volume/csi/testing"
 	"k8s.io/kubernetes/pkg/volume/gcepd"
 	volumetesting "k8s.io/kubernetes/pkg/volume/testing"
+	"k8s.io/kubernetes/pkg/volume/util"
 	volumetypes "k8s.io/kubernetes/pkg/volume/util/types"
 )
 
@@ -91,30 +91,15 @@ func TestOperationGenerator_GenerateUnmapVolumeFunc_PluginName(t *testing.T) {
 			t.Fatalf("Error occurred while generating unmapVolumeFunc: %v", e)
 		}
 
-		metricFamilyName := "storage_operation_duration_seconds"
-		labelFilter := map[string]string{
-			"migrated":       "false",
-			"status":         "success",
-			"operation_name": "unmap_volume",
-			"volume_plugin":  expectedPluginName,
-		}
-		// compare the relative change of the metric because of the global state of the prometheus.DefaultGatherer.Gather()
-		storageOperationDurationSecondsMetricBefore := findMetricWithNameAndLabels(metricFamilyName, labelFilter)
+		m := util.StorageOperationMetric.WithLabelValues(expectedPluginName, "unmap_volume", "success", "false")
+		storageOperationDurationSecondsMetricBefore, _ := testutil.GetHistogramMetricCount(m)
 
 		var ee error
 		unmapVolumeFunc.CompleteFunc(volumetypes.CompleteFuncParam{Err: &ee})
 
-		storageOperationDurationSecondsMetricAfter := findMetricWithNameAndLabels(metricFamilyName, labelFilter)
-		if storageOperationDurationSecondsMetricAfter == nil {
-			t.Fatalf("Couldn't find the metric with name(%s) and labels(%v)", metricFamilyName, labelFilter)
-		}
-
-		if storageOperationDurationSecondsMetricBefore == nil {
-			assert.Equal(t, uint64(1), *storageOperationDurationSecondsMetricAfter.Histogram.SampleCount, tc.name)
-		} else {
-			metricValueDiff := *storageOperationDurationSecondsMetricAfter.Histogram.SampleCount - *storageOperationDurationSecondsMetricBefore.Histogram.SampleCount
-			assert.Equal(t, uint64(1), metricValueDiff, tc.name)
-		}
+		storageOperationDurationSecondsMetricAfter, _ := testutil.GetHistogramMetricCount(m)
+		metricValueDiff := storageOperationDurationSecondsMetricAfter - storageOperationDurationSecondsMetricBefore
+		assert.Equal(t, uint64(1), metricValueDiff, tc.name)
 	}
 }
 
@@ -406,40 +391,6 @@ func getTestPV(volumeName string, specSize string) *v1.PersistentVolume {
 	}
 }
 
-func findMetricWithNameAndLabels(metricFamilyName string, labelFilter map[string]string) *io_prometheus_client.Metric {
-	metricFamily := getMetricFamily(metricFamilyName)
-	if metricFamily == nil {
-		return nil
-	}
-
-	for _, metric := range metricFamily.GetMetric() {
-		if isLabelsMatchWithMetric(labelFilter, metric) {
-			return metric
-		}
-	}
-
-	return nil
-}
-
-func isLabelsMatchWithMetric(labelFilter map[string]string, metric *io_prometheus_client.Metric) bool {
-	if len(labelFilter) != len(metric.Label) {
-		return false
-	}
-	for labelName, labelValue := range labelFilter {
-		labelFound := false
-		for _, labelPair := range metric.Label {
-			if labelName == *labelPair.Name && labelValue == *labelPair.Value {
-				labelFound = true
-				break
-			}
-		}
-		if !labelFound {
-			return false
-		}
-	}
-	return true
-}
-
 func getTestOperationGenerator(volumePluginMgr *volume.VolumePluginMgr, objects ...runtime.Object) OperationGenerator {
 	fakeKubeClient := fakeclient.NewSimpleClientset(objects...)
 	fakeRecorder := &record.FakeRecorder{}
@@ -492,16 +443,6 @@ func getTestVolumeToUnmount(pod *v1.Pod, pvSpec v1.PersistentVolumeSpec, pluginN
 	return volumeToUnmount
 }
 
-func getMetricFamily(metricFamilyName string) *io_prometheus_client.MetricFamily {
-	metricFamilies, _ := legacyregistry.DefaultGatherer.Gather()
-	for _, mf := range metricFamilies {
-		if *mf.Name == metricFamilyName {
-			return mf
-		}
-	}
-	return nil
-}
-
 func initTestPlugins(t *testing.T, plugs []volume.VolumePlugin, pluginName string) (*volume.VolumePluginMgr, string) {
 	client := fakeclient.NewSimpleClientset()
 	pluginMgr, _, tmpDir := csitesting.NewTestPlugin(t, client)