Auto-update Go Collector Metrics for new Go versions

Makefile

@@ -21,7 +21,9 @@ test: deps common-test
 test-short: deps common-test-short
 
 .PHONY: generate-go-collector-test-files
-VERSIONS := 1.20 1.21 1.22
+file := supported_go_versions.txt
+# take top 3 versions
+VERSIONS := $(shell cat ${file} | head -n 3)
 generate-go-collector-test-files:
 	for GO_VERSION in $(VERSIONS); do \
 		docker run \

generate-go-collector.bash

@@ -5,3 +5,5 @@ set -e
 go get github.com/hashicorp/go-version@v1.6.0
 go run prometheus/gen_go_collector_metrics_set.go
 mv -f go_collector_metrics_* prometheus
+go run prometheus/collectors/gen_go_collector_set.go
+mv -f go_collector_* prometheus/collectors

prometheus/collectors/gen_go_collector_set.go

@@ -0,0 +1,214 @@
+// Copyright 2021 The Prometheus Authors
+// 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.
+
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"log"
+	"os"
+	"regexp"
+	"runtime"
+	"runtime/metrics"
+	"sort"
+	"strings"
+	"text/template"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/internal"
+
+	version "github.com/hashicorp/go-version"
+)
+
+type metricGroup struct {
+	Name    string
+	Regex   *regexp.Regexp
+	Metrics []string
+}
+
+var metricGroups = []metricGroup{
+	{"withAllMetrics", nil, nil},
+	{"withGCMetrics", regexp.MustCompile("^go_gc_.*"), nil},
+	{"withMemoryMetrics", regexp.MustCompile("^go_memory_classes_.*"), nil},
+	{"withSchedulerMetrics", regexp.MustCompile("^go_sched_.*"), nil},
+	{"withDebugMetrics", regexp.MustCompile("^go_godebug_non_default_behavior_.*"), nil},
+}
+
+func main() {
+	var givenVersion string
+	toolVersion := runtime.Version()
+	if len(os.Args) != 2 {
+		log.Printf("requires Go version (e.g. go1.17) as an argument. Since it is not specified, assuming %s.", toolVersion)
+		givenVersion = toolVersion
+	} else {
+		givenVersion = os.Args[1]
+	}
+	log.Printf("given version for Go: %s", givenVersion)
+	log.Printf("tool version for Go: %s", toolVersion)
+
+	tv, err := version.NewVersion(strings.TrimPrefix(givenVersion, "go"))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	toolVersion = strings.Split(strings.TrimPrefix(toolVersion, "go"), " ")[0]
+	gv, err := version.NewVersion(toolVersion)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if !gv.Equal(tv) {
+		log.Fatalf("using Go version %q but expected Go version %q", tv, gv)
+	}
+
+	v := goVersion(gv.Segments()[1])
+	log.Printf("generating metrics for Go version %q", v)
+
+	descriptions := computeMetricsList()
+	groupedMetrics := groupMetrics(descriptions)
+
+	// Generate code.
+	var buf bytes.Buffer
+	err = testFile.Execute(&buf, struct {
+		GoVersion goVersion
+		Groups    []metricGroup
+	}{
+		GoVersion: v,
+		Groups:    groupedMetrics,
+	})
+	if err != nil {
+		log.Fatalf("executing template: %v", err)
+	}
+
+	// Format it.
+	result, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatalf("formatting code: %v", err)
+	}
+
+	// Write it to a file.
+	fname := fmt.Sprintf("go_collector_%s_test.go", v.Abbr())
+	if err := os.WriteFile(fname, result, 0o644); err != nil {
+		log.Fatalf("writing file: %v", err)
+	}
+}
+
+func computeMetricsList() []string {
+	var metricsList []string
+	for _, d := range metrics.All() {
+		if trans := rm2prom(d); trans != "" {
+			metricsList = append(metricsList, trans)
+		}
+	}
+	return metricsList
+}
+
+func rm2prom(d metrics.Description) string {
+	ns, ss, n, ok := internal.RuntimeMetricsToProm(&d)
+	if !ok {
+		return ""
+	}
+	return prometheus.BuildFQName(ns, ss, n)
+}
+
+func groupMetrics(metricsList []string) []metricGroup {
+	var groupedMetrics []metricGroup
+	for _, group := range metricGroups {
+		var matchedMetrics []string
+		for _, metric := range metricsList {
+			if group.Regex == nil || group.Regex.MatchString(metric) {
+				matchedMetrics = append(matchedMetrics, metric)
+			}
+		}
+
+		// Scheduler metrics is `sched` regex plus base metrics
+		// List of base metrics are taken from here: https://github.com/prometheus/client_golang/blob/26e3055e5133a9d64e8e5a07a7cf026875d5f55d/prometheus/go_collector.go#L208
+		if group.Name == "withSchedulerMetrics" {
+			baseMatrices := []string{
+				"go_gc_duration_seconds",
+				"go_goroutines",
+				"go_info",
+				"go_memstats_last_gc_time_seconds",
+				"go_threads",
+			}
+			matchedMetrics = append(matchedMetrics, baseMatrices...)
+		}
+		sort.Strings(matchedMetrics)
+		if len(matchedMetrics) > 0 {
+			groupedMetrics = append(groupedMetrics, metricGroup{
+				Name:    group.Name,
+				Regex:   group.Regex,
+				Metrics: matchedMetrics,
+			})
+		}
+	}
+	return groupedMetrics
+}
+
+type goVersion int
+
+func (g goVersion) String() string {
+	return fmt.Sprintf("go1.%d", g)
+}
+
+func (g goVersion) Abbr() string {
+	return fmt.Sprintf("go1%d", g)
+}
+
+var testFile = template.Must(template.New("testFile").Funcs(map[string]interface{}{
+	"nextVersion": func(version goVersion) string {
+		return (version + goVersion(1)).String()
+	},
+	"needsBaseMetrics": func(groupName string) bool {
+		return groupName == "withAllMetrics" || groupName == "withGCMetrics" || groupName == "withMemoryMetrics"
+	},
+}).Parse(`// Copyright 2022 The Prometheus Authors
+// 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.
+
+//go:build {{.GoVersion}} && !{{nextVersion .GoVersion}}
+// +build {{.GoVersion}},!{{nextVersion .GoVersion}}
+
+package collectors
+
+{{- range .Groups }}
+func {{ .Name }}() []string {
+	{{- if needsBaseMetrics .Name }}
+	return withBaseMetrics([]string{
+		{{- range $metric := .Metrics }}
+			{{ $metric | printf "%q" }},
+		{{- end }}
+	})
+	{{- else }}
+	return []string{
+		{{- range $metric := .Metrics }}
+			{{ $metric | printf "%q" }},
+		{{- end }}
+	}
+	{{- end }}
+}
+{{ end }}
+`))

supported_go_versions.txt

@@ -0,0 +1,3 @@
+1.22
+1.21
+1.20