Refactor test utils that deal with Kubelet metrics for clarity

test/e2e/framework/kubelet_stats.go

@@ -97,10 +97,11 @@ func getKubeletMetrics(c clientset.Interface, nodeName string) (metrics.KubeletM
 	return kubeletMetrics, nil
 }
 
-// GetKubeletLatencyMetrics gets all latency related kubelet metrics. Note that the KubeletMetrcis
-// passed in should not contain subsystem prefix.
-func GetKubeletLatencyMetrics(ms metrics.KubeletMetrics) KubeletLatencyMetrics {
-	latencyMethods := sets.NewString(
+// GetDefaultKubeletLatencyMetrics calls GetKubeletLatencyMetrics with a set of default metricNames
+// identifying common latency metrics.
+// Note that the KubeletMetrics passed in should not contain subsystem prefix.
+func GetDefaultKubeletLatencyMetrics(ms metrics.KubeletMetrics) KubeletLatencyMetrics {
+	latencyMetricNames := sets.NewString(
 		kubeletmetrics.PodWorkerLatencyKey,
 		kubeletmetrics.PodWorkerStartLatencyKey,
 		kubeletmetrics.PodStartLatencyKey,
@@ -109,13 +110,15 @@ func GetKubeletLatencyMetrics(ms metrics.KubeletMetrics) KubeletLatencyMetrics {
 		kubeletmetrics.PodWorkerStartLatencyKey,
 		kubeletmetrics.PLEGRelistLatencyKey,
 	)
-	return GetKubeletMetrics(ms, latencyMethods)
+	return GetKubeletLatencyMetrics(ms, latencyMetricNames)
 }
 
-func GetKubeletMetrics(ms metrics.KubeletMetrics, methods sets.String) KubeletLatencyMetrics {
+// GetKubeletLatencyMetrics filters ms to include only those contained in the metricNames set,
+// then constructs a KubeletLatencyMetrics list based on the samples associated with those metrics.
+func GetKubeletLatencyMetrics(ms metrics.KubeletMetrics, filterMetricNames sets.String) KubeletLatencyMetrics {
 	var latencyMetrics KubeletLatencyMetrics
-	for method, samples := range ms {
-		if !methods.Has(method) {
+	for name, samples := range ms {
+		if !filterMetricNames.Has(name) {
 			continue
 		}
 		for _, sample := range samples {
@@ -131,7 +134,7 @@ func GetKubeletMetrics(ms metrics.KubeletMetrics, methods sets.String) KubeletLa
 
 			latencyMetrics = append(latencyMetrics, KubeletLatencyMetric{
 				Operation: operation,
-				Method:    method,
+				Method:    name,
 				Quantile:  quantile,
 				Latency:   time.Duration(int64(latency)) * time.Microsecond,
 			})
@@ -265,7 +268,7 @@ func HighLatencyKubeletOperations(c clientset.Interface, threshold time.Duration
 	if err != nil {
 		return KubeletLatencyMetrics{}, err
 	}
-	latencyMetrics := GetKubeletLatencyMetrics(ms)
+	latencyMetrics := GetDefaultKubeletLatencyMetrics(ms)
 	sort.Sort(latencyMetrics)
 	var badMetrics KubeletLatencyMetrics
 	logFunc("\nLatency metrics for node %v", nodeName)

test/e2e_node/eviction_test.go

@@ -411,7 +411,7 @@ func runEvictionTest(f *framework.Framework, pressureTimeout time.Duration, expe
 						framework.Logf("Node does NOT have %s", expectedNodeCondition)
 					}
 				}
-				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
+				logKubeletLatencyMetrics(kubeletmetrics.EvictionStatsAgeKey)
 				logFunc()
 				return verifyEvictionOrdering(f, testSpecs)
 			}, pressureTimeout, evictionPollInterval).Should(BeNil())
@@ -425,7 +425,7 @@ func runEvictionTest(f *framework.Framework, pressureTimeout time.Duration, expe
 			By(fmt.Sprintf("Waiting for NodeCondition: %s to no longer exist on the node", expectedNodeCondition))
 			Eventually(func() error {
 				logFunc()
-				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
+				logKubeletLatencyMetrics(kubeletmetrics.EvictionStatsAgeKey)
 				if expectedNodeCondition != noPressure && hasNodeCondition(f, expectedNodeCondition) {
 					return fmt.Errorf("Conditions havent returned to normal, node still has %s", expectedNodeCondition)
 				}
@@ -438,7 +438,7 @@ func runEvictionTest(f *framework.Framework, pressureTimeout time.Duration, expe
 					return fmt.Errorf("%s dissappeared and then reappeared", expectedNodeCondition)
 				}
 				logFunc()
-				logKubeletMetrics(kubeletmetrics.EvictionStatsAgeKey)
+				logKubeletLatencyMetrics(kubeletmetrics.EvictionStatsAgeKey)
 				return verifyEvictionOrdering(f, testSpecs)
 			}, postTestConditionMonitoringPeriod, evictionPollInterval).Should(BeNil())
 		})

test/e2e_node/util.go

@@ -331,17 +331,19 @@ func getLocalNode(f *framework.Framework) *apiv1.Node {
 	return &nodeList.Items[0]
 }
 
-// logs prometheus metrics from the local kubelet.
-func logKubeletMetrics(metricKeys ...string) {
+// logKubeletLatencyMetrics logs KubeletLatencyMetrics computed from the Prometheus
+// metrics exposed on the current node and identified by the metricNames.
+// The Kubelet subsystem prefix is automatically prepended to these metric names.
+func logKubeletLatencyMetrics(metricNames ...string) {
 	metricSet := sets.NewString()
-	for _, key := range metricKeys {
+	for _, key := range metricNames {
 		metricSet.Insert(kubeletmetrics.KubeletSubsystem + "_" + key)
 	}
 	metric, err := metrics.GrabKubeletMetricsWithoutProxy(framework.TestContext.NodeName + ":10255")
 	if err != nil {
 		framework.Logf("Error getting kubelet metrics: %v", err)
 	} else {
-		framework.Logf("Kubelet Metrics: %+v", framework.GetKubeletMetrics(metric, metricSet))
+		framework.Logf("Kubelet Metrics: %+v", framework.GetKubeletLatencyMetrics(metric, metricSet))
 	}
 }