Add presubmit to check stable metrics aren't changed

Makefile

@@ -8,7 +8,7 @@ LATEST_RELEASE_BRANCH := release-$(shell grep -ohE "[0-9]+.[0-9]+" VERSION)
 BRANCH = $(strip $(shell git rev-parse --abbrev-ref HEAD))
 DOCKER_CLI ?= docker
 PROMTOOL_CLI ?= promtool
-PKGS = $(shell go list ./... | grep -v /vendor/ | grep -v /tests/e2e)
+PKGS = $(shell go list ./... | grep -v /vendor/ | grep -v /tests/e2e | grep -v /tests/stable)
 ARCH ?= $(shell go env GOARCH)
 BUILD_DATE = $(shell date -u +'%Y-%m-%dT%H:%M:%SZ')
 GIT_COMMIT ?= $(shell git rev-parse --short HEAD)

tests/e2e.sh

@@ -15,6 +15,7 @@
 # limitations under the License.
 
 set -e
+set -x
 set -o pipefail
 
 case $(uname -m) in
@@ -163,6 +164,10 @@ mkdir -p ${KUBE_STATE_METRICS_LOG_DIR}
 echo "access kube-state-metrics metrics endpoint"
 curl -s "http://localhost:8001/api/v1/namespaces/kube-system/services/kube-state-metrics:http-metrics/proxy/metrics" >${KUBE_STATE_METRICS_LOG_DIR}/metrics
 
+cat ${KUBE_STATE_METRICS_LOG_DIR}/metrics
+# check stable metrics aren't changed
+go test ./tests/stable/check_test.go --collectedMetricsFile "$(realpath ${KUBE_STATE_METRICS_LOG_DIR}/metrics)"  --stableMetricsFile "$(realpath tests/stable/testdata/stablemetrics.yaml)"
+
 KUBE_STATE_METRICS_STATUS=$(curl -s "http://localhost:8001/api/v1/namespaces/kube-system/services/kube-state-metrics:http-metrics/proxy/healthz")
 if [[ "${KUBE_STATE_METRICS_STATUS}" == "OK" ]]; then
     echo "kube-state-metrics is still running after accessing metrics endpoint"

tests/stable/check_test.go

@@ -0,0 +1,193 @@
+/*
+Copyright 2022 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package stable
+
+import (
+	"flag"
+	"fmt"
+	"testing"
+
+	"log"
+	"os"
+	"strings"
+
+	"github.com/google/go-cmp/cmp"
+	prommodel "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/expfmt"
+	"gopkg.in/yaml.v3"
+
+	"github.com/google/go-cmp/cmp/cmpopts"
+)
+
+var promText string
+var stableYaml string
+
+var skipStableMetrics = []string{
+}
+
+type Metric struct {
+	Name   string `yaml:"name"`
+	Help   string `yaml:"help"`
+	Type   string
+	Labels []string
+	// Histogram type
+	Buckets []float64 `yaml:"buckets,omitempty"`
+}
+
+func TestMain(m *testing.M) {
+	flag.StringVar(&promText, "collectedMetricsFile", "", "input prometheus metrics text file, text format")
+	flag.StringVar(&stableYaml, "stableMetricsFile", "", "expected stable metrics yaml file, yaml format")
+	flag.Parse()
+	m.Run()
+}
+
+func TestStableMetrics(t *testing.T) {
+	mf, err := parsePromText(promText)
+	fatal(err)
+	collectedStableMetrics := extractStableMetrics(mf)
+	printMetric(collectedStableMetrics)
+
+	expectedStableMetrics, err := readYaml(stableYaml)
+	if err != nil {
+		t.Fatalf("Can't read stable metrics from file. err = %v", err)
+	}
+
+	err = compare(collectedStableMetrics, *expectedStableMetrics, skipStableMetrics)
+	if err != nil {
+		t.Fatalf("Stable metrics changed: err = %v", err)
+	} else {
+		fmt.Println("passed")
+	}
+
+}
+
+func fatal(err error) {
+	if err != nil {
+		log.Fatalln(err)
+	}
+}
+
+func printMetric(metrics []Metric) {
+	yamlData, err := yaml.Marshal(metrics)
+	if err != nil {
+		fmt.Printf("error while Marshaling. %v", err)
+	}
+	fmt.Println("---begin YAML file---")
+	fmt.Println(string(yamlData))
+	fmt.Println("---end YAML file---")
+}
+
+func parsePromText(path string) (map[string]*prommodel.MetricFamily, error) {
+	reader, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	var parser expfmt.TextParser
+	mf, err := parser.TextToMetricFamilies(reader)
+	if err != nil {
+		return nil, err
+	}
+	return mf, nil
+}
+
+func getBuckets(v *prommodel.MetricFamily) []float64 {
+	buckets := []float64{}
+	if v.GetType() == prommodel.MetricType_HISTOGRAM {
+		for _, bucket := range v.Metric[0].GetHistogram().GetBucket() {
+			buckets = append(buckets, *bucket.UpperBound)
+		}
+	} else {
+		buckets = nil
+	}
+	return buckets
+}
+
+func extractStableMetrics(mf map[string]*prommodel.MetricFamily) []Metric {
+	metrics := []Metric{}
+	for _, v := range mf {
+		if !strings.Contains(*(v.Help), "[STABLE]") {
+			continue
+		}
+
+		m := Metric{
+			Name:    *(v.Name),
+			Help:    *(v.Help),
+			Type:    (v.Type).String(),
+			Buckets: getBuckets(v),
+		}
+		labels := []string{}
+		for _, y := range v.Metric[0].Label {
+			labels = append(labels, y.GetName())
+		}
+		m.Labels = labels
+		metrics = append(metrics, m)
+	}
+	return metrics
+}
+
+func readYaml(filename string) (*[]Metric, error) {
+	buf, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	c := &[]Metric{}
+	err = yaml.Unmarshal(buf, c)
+	if err != nil {
+		return nil, fmt.Errorf("error %q: %w", filename, err)
+	}
+	return c, err
+}
+
+func convert2Map(metrics []Metric, skipMap map[string]int) map[string]Metric {
+	name2Metric := map[string]Metric{}
+	for _, v := range metrics {
+		if _, ok := skipMap[v.Name]; ok {
+			fmt.Printf("skip, metric %s is in skip list\n", v.Name)
+			continue
+		}
+		name2Metric[v.Name] = v
+	}
+	return name2Metric
+
+}
+
+func compare(collectedStableMetrics []Metric, expectedStableMetrics []Metric, skipStableMetrics []string) error {
+	skipMap := map[string]int{}
+	for _, v := range skipStableMetrics {
+		skipMap[v] = 1
+	}
+	collected := convert2Map(collectedStableMetrics, skipMap)
+	expected := convert2Map(expectedStableMetrics, skipMap)
+
+	var ok bool
+
+	for name, metric := range expected {
+		var expectedMetric Metric
+		if expectedMetric, ok = collected[name]; !ok {
+			return fmt.Errorf("not found stable metric %s", name)
+		}
+		if diff := cmp.Diff(metric, expectedMetric, cmpopts.IgnoreFields(Metric{}, "Help")); diff != "" {
+			return fmt.Errorf("stable metric %s mismatch (-want +got):\n%s", name, diff)
+		}
+	}
+	for name := range collected {
+		if _, ok = expected[name]; !ok {
+			return fmt.Errorf("detected new stable metric %s which isn't in testdata ", name)
+		}
+	}
+	return nil
+}