From 7b616b39b1fa9e9f1345cd6701e488f791e1fa93 Mon Sep 17 00:00:00 2001
From: Han Kang <hankang@google.com>
Date: Mon, 17 Oct 2022 13:26:15 -0700
Subject: [PATCH] add support for merging calls to Linear/Exponential Buckets

Change-Id: Id6005912ac71c9c15354e9e8242f0febf8569dec
---
 test/instrumentation/decode_metric.go         | 32 +++++++
 .../testdata/pkg/kubelet/metrics/metrics.go   | 24 ++++++
 .../testdata/test-stable-metrics-list.yaml    | 86 +++++++++++++++++++
 3 files changed, 142 insertions(+)

diff --git a/test/instrumentation/decode_metric.go b/test/instrumentation/decode_metric.go
index 1c1cf582480..df9323e7ee3 100644
--- a/test/instrumentation/decode_metric.go
+++ b/test/instrumentation/decode_metric.go
@@ -438,6 +438,38 @@ func (c *metricDecoder) decodeBuckets(expr ast.Expr) ([]float64, error) {
 func (c *metricDecoder) decodeBucketFunctionCall(v *ast.CallExpr) ([]float64, error, bool) {
 	se, ok := v.Fun.(*ast.SelectorExpr)
 	if !ok {
+		// support merged
+		if ai, ok := v.Fun.(*ast.Ident); ok && ai.Name == "merge" {
+			merged := []float64{}
+			for _, arg := range v.Args {
+				v2, ok := arg.(*ast.CallExpr)
+				if !ok {
+					return nil, newDecodeErrorf(v2, errBuckets), true
+				}
+				se, ok = v2.Fun.(*ast.SelectorExpr)
+				if ok {
+					functionName := se.Sel.String()
+					functionImport, ok := se.X.(*ast.Ident)
+					if !ok {
+						return nil, newDecodeErrorf(v, errBuckets), true
+					}
+					if functionImport.String() != c.kubeMetricsImportName {
+						return nil, newDecodeErrorf(v, errBuckets), true
+					}
+					firstArg, secondArg, thirdArg, err := decodeBucketArguments(v2)
+					if err != nil {
+						return nil, err, true
+					}
+					switch functionName {
+					case "LinearBuckets":
+						merged = append(merged, metrics.LinearBuckets(firstArg, secondArg, thirdArg)...)
+					case "ExponentialBuckets":
+						merged = append(merged, metrics.LinearBuckets(firstArg, secondArg, thirdArg)...)
+					}
+				}
+			}
+			return merged, nil, true
+		}
 		return nil, newDecodeErrorf(v, errBuckets), true
 	}
 	functionName := se.Sel.String()
diff --git a/test/instrumentation/testdata/pkg/kubelet/metrics/metrics.go b/test/instrumentation/testdata/pkg/kubelet/metrics/metrics.go
index 5a8181c6ab5..4b483bff2fc 100644
--- a/test/instrumentation/testdata/pkg/kubelet/metrics/metrics.go
+++ b/test/instrumentation/testdata/pkg/kubelet/metrics/metrics.go
@@ -473,6 +473,21 @@ var (
 		},
 		[]string{"container_state"},
 	)
+
+	NetworkProgrammingLatency = metrics.NewHistogram(
+		&metrics.HistogramOpts{
+			Subsystem: "kube_proxy",
+			Name:      "network_programming_duration_seconds",
+			Help:      "In Cluster Network Programming Latency in seconds",
+			Buckets: merge(
+				metrics.LinearBuckets(0.25, 0.25, 2), // 0.25s, 0.50s
+				metrics.LinearBuckets(1, 1, 59),      // 1s, 2s, 3s, ... 59s
+				metrics.LinearBuckets(60, 5, 12),     // 60s, 65s, 70s, ... 115s
+				metrics.LinearBuckets(120, 30, 7),    // 2min, 2.5min, 3min, ..., 5min
+			),
+			StabilityLevel: metrics.BETA,
+		},
+	)
 )
 
 var registerMetrics sync.Once
@@ -503,6 +518,7 @@ func Register(collectors ...metrics.StableCollector) {
 		legacyregistry.MustRegister(RunningPodCount)
 		legacyregistry.MustRegister(RunPodSandboxDuration)
 		legacyregistry.MustRegister(RunPodSandboxErrors)
+		legacyregistry.MustRegister(NetworkProgrammingLatency)
 		for _, collector := range collectors {
 			legacyregistry.CustomMustRegister(collector)
 		}
@@ -547,3 +563,11 @@ func SetNodeName(name types.NodeName) {
 func Blah() metrics.ObserverMetric {
 	return EvictionStatsAge.With(metrics.Labels{"plugins": "ASDf"})
 }
+
+func merge(slices ...[]float64) []float64 {
+	result := make([]float64, 1)
+	for _, s := range slices {
+		result = append(result, s...)
+	}
+	return result
+}
diff --git a/test/instrumentation/testdata/test-stable-metrics-list.yaml b/test/instrumentation/testdata/test-stable-metrics-list.yaml
index d6cc66b59aa..da3466d4d9d 100644
--- a/test/instrumentation/testdata/test-stable-metrics-list.yaml
+++ b/test/instrumentation/testdata/test-stable-metrics-list.yaml
@@ -1,3 +1,89 @@
+- name: network_programming_duration_seconds
+  subsystem: kube_proxy
+  help: In Cluster Network Programming Latency in seconds
+  type: Histogram
+  stabilityLevel: BETA
+  buckets:
+  - 0.25
+  - 0.5
+  - 1
+  - 2
+  - 3
+  - 4
+  - 5
+  - 6
+  - 7
+  - 8
+  - 9
+  - 10
+  - 11
+  - 12
+  - 13
+  - 14
+  - 15
+  - 16
+  - 17
+  - 18
+  - 19
+  - 20
+  - 21
+  - 22
+  - 23
+  - 24
+  - 25
+  - 26
+  - 27
+  - 28
+  - 29
+  - 30
+  - 31
+  - 32
+  - 33
+  - 34
+  - 35
+  - 36
+  - 37
+  - 38
+  - 39
+  - 40
+  - 41
+  - 42
+  - 43
+  - 44
+  - 45
+  - 46
+  - 47
+  - 48
+  - 49
+  - 50
+  - 51
+  - 52
+  - 53
+  - 54
+  - 55
+  - 56
+  - 57
+  - 58
+  - 59
+  - 60
+  - 65
+  - 70
+  - 75
+  - 80
+  - 85
+  - 90
+  - 95
+  - 100
+  - 105
+  - 110
+  - 115
+  - 120
+  - 150
+  - 180
+  - 210
+  - 240
+  - 270
+  - 300
 - name: certificate_manager_client_ttl_seconds
   subsystem: kubelet
   help: Gauge of the TTL (time-to-live) of the Kubelet's client certificate. The value