Generate new Go runtime metrics for go 1.19 (#1105)

* Generate new Go runtime metrics

Fix generation script

Signed-off-by: Kemal Akkoyun <[email protected]>

* Address review issues

Signed-off-by: Kemal Akkoyun <[email protected]>

.github/workflows/golangci-lint.yml

@@ -20,7 +20,7 @@ jobs:
       - name: install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.18.x
+          go-version-file: .go-version
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'

.go-version

@@ -0,0 +1 @@
+1.18

Makefile

@@ -18,3 +18,11 @@ test: deps common-test
 
 .PHONY: test-short
 test-short: deps common-test-short
+
+.PHONY: generate-go-collector-test-files
+VERSIONS := 1.17 1.18 1.19
+generate-go-collector-test-files:
+	for GO_VERSION in $(VERSIONS); do \
+    	docker run --rm -v $(PWD):/workspace -w /workspace golang:$$GO_VERSION go run prometheus/gen_go_collector_metrics_set.go; \
+		mv -f go_collector_metrics* prometheus; \
+    done

prometheus/gen_go_collector_metrics_set.go

@@ -25,29 +25,42 @@ import (
 	"os"
 	"runtime"
 	"runtime/metrics"
-	"strconv"
 	"strings"
 	"text/template"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/internal"
+
+	"github.com/hashicorp/go-version"
 )
 
 func main() {
+	var givenVersion string
+	toolVersion := runtime.Version()
 	if len(os.Args) != 2 {
-		log.Fatal("requires Go version (e.g. go1.17) as an argument")
+		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]
 	}
-	toolVersion := runtime.Version()
-	mtv := majorVersion(toolVersion)
-	mv := majorVersion(os.Args[1])
-	if mtv != mv {
-		log.Fatalf("using Go version %q but expected Go version %q", mtv, mv)
+	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)
 	}
-	version, err := parseVersion(mv)
+	gv, err := version.NewVersion(strings.TrimPrefix(toolVersion, "go"))
 	if err != nil {
-		log.Fatalf("parsing Go version: %v", err)
+		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)
+
 	// Generate code.
 	var buf bytes.Buffer
 	err = testFile.Execute(&buf, struct {
@@ -56,7 +69,7 @@ func main() {
 		Cardinality  int
 	}{
 		Descriptions: metrics.All(),
-		GoVersion:    version,
+		GoVersion:    v,
 		Cardinality:  rmCardinality(),
 	})
 	if err != nil {
@@ -70,7 +83,7 @@ func main() {
 	}
 
 	// Write it to a file.
-	fname := fmt.Sprintf("go_collector_metrics_%s_test.go", version.Abbr())
+	fname := fmt.Sprintf("go_collector_metrics_%s_test.go", v.Abbr())
 	if err := os.WriteFile(fname, result, 0o644); err != nil {
 		log.Fatalf("writing file: %v", err)
 	}
@@ -86,19 +99,6 @@ func (g goVersion) Abbr() string {
 	return fmt.Sprintf("go1%d", g)
 }
 
-func parseVersion(s string) (goVersion, error) {
-	i := strings.IndexRune(s, '.')
-	if i < 0 {
-		return goVersion(-1), fmt.Errorf("bad Go version format")
-	}
-	i, err := strconv.Atoi(s[i+1:])
-	return goVersion(i), err
-}
-
-func majorVersion(v string) string {
-	return v[:strings.LastIndexByte(v, '.')]
-}
-
 func rmCardinality() int {
 	cardinality := 0
 
@@ -123,6 +123,7 @@ func rmCardinality() int {
 			name[strings.IndexRune(name, ':')+1:],
 		)
 		cardinality += len(buckets) + 3 // Plus total count, sum, and the implicit infinity bucket.
+
 		// runtime/metrics bucket boundaries are lower-bound-inclusive, but
 		// always represents each actual *boundary* so Buckets is always
 		// 1 longer than Counts, while in Prometheus the mapping is one-to-one,
@@ -134,6 +135,12 @@ func rmCardinality() int {
 			// We already counted the infinity bucket separately.
 			cardinality--
 		}
+		// Prometheus also doesn't have buckets for -Inf, so they need to be omitted.
+		// See the following PR for more information:
+		// https://github.com/prometheus/client_golang/pull/1049
+		if buckets[0] == math.Inf(-1) {
+			cardinality--
+		}
 	}
 
 	return cardinality

prometheus/go_collector_latest_test.go

@@ -269,7 +269,7 @@ func TestMemStatsEquivalence(t *testing.T) {
 }
 
 func TestExpectedRuntimeMetrics(t *testing.T) {
-	goMetrics := collectGoMetrics(t, goRuntimeMetricsCollection)
+	goMetrics := collectGoMetrics(t, goRuntimeMemStatsCollection|goRuntimeMetricsCollection)
 	goMetricSet := make(map[string]Metric)
 	for _, m := range goMetrics {
 		goMetricSet[m.Desc().fqName] = m