gocollector: Add regex option to allow collection of debug runtime me…

…trics

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

prometheus/collectors/gen_go_collector_set.go

@@ -128,7 +128,7 @@ func rm2prom(d metrics.Description) string {
 func groupMetrics(metricsList []string) []metricGroup {
 	var groupedMetrics []metricGroup
 	for _, group := range metricGroups {
-		var matchedMetrics []string
+		matchedMetrics := make([]string, 0)
 		for _, metric := range metricsList {
 			if group.Regex == nil || group.Regex.MatchString(metric) {
 				matchedMetrics = append(matchedMetrics, metric)
@@ -148,13 +148,11 @@ func groupMetrics(metricsList []string) []metricGroup {
 			matchedMetrics = append(matchedMetrics, baseMatrices...)
 		}
 		sort.Strings(matchedMetrics)
-		if len(matchedMetrics) > 0 {
-			groupedMetrics = append(groupedMetrics, metricGroup{
-				Name:    group.Name,
-				Regex:   group.Regex,
-				Metrics: matchedMetrics,
-			})
-		}
+		groupedMetrics = append(groupedMetrics, metricGroup{
+			Name:    group.Name,
+			Regex:   group.Regex,
+			Metrics: matchedMetrics,
+		})
 	}
 	return groupedMetrics
 }
@@ -174,7 +172,7 @@ var testFile = template.Must(template.New("testFile").Funcs(map[string]interface
 		return (version + goVersion(1)).String()
 	},
 	"needsBaseMetrics": func(groupName string) bool {
-		return groupName == "withAllMetrics" || groupName == "withGCMetrics" || groupName == "withMemoryMetrics"
+		return groupName == "withAllMetrics" || groupName == "withGCMetrics" || groupName == "withMemoryMetrics" || groupName == "withDebugMetrics"
 	},
 }).Parse(`// Copyright 2022 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");

prometheus/collectors/go_collector_go117_test.go

@@ -98,3 +98,7 @@ func withSchedulerMetrics() []string {
 		"go_threads",
 	}
 }
+
+func withDebugMetrics() []string {
+	return withBaseMetrics([]string{})
+}

prometheus/collectors/go_collector_go119_test.go

@@ -105,3 +105,7 @@ func withSchedulerMetrics() []string {
 		"go_threads",
 	}
 }
+
+func withDebugMetrics() []string {
+	return withBaseMetrics([]string{})
+}

prometheus/collectors/go_collector_go120_test.go

@@ -19,9 +19,6 @@ package collectors
 func withAllMetrics() []string {
 	return withBaseMetrics([]string{
 		"go_cgo_go_to_c_calls_calls_total",
-		"go_gc_cycles_automatic_gc_cycles_total",
-		"go_gc_cycles_forced_gc_cycles_total",
-		"go_gc_cycles_total_gc_cycles_total",
 		"go_cpu_classes_gc_mark_assist_cpu_seconds_total",
 		"go_cpu_classes_gc_mark_dedicated_cpu_seconds_total",
 		"go_cpu_classes_gc_mark_idle_cpu_seconds_total",
@@ -33,6 +30,9 @@ func withAllMetrics() []string {
 		"go_cpu_classes_scavenge_total_cpu_seconds_total",
 		"go_cpu_classes_total_cpu_seconds_total",
 		"go_cpu_classes_user_cpu_seconds_total",
+		"go_gc_cycles_automatic_gc_cycles_total",
+		"go_gc_cycles_forced_gc_cycles_total",
+		"go_gc_cycles_total_gc_cycles_total",
 		"go_gc_heap_allocs_by_size_bytes",
 		"go_gc_heap_allocs_bytes_total",
 		"go_gc_heap_allocs_objects_total",
@@ -117,3 +117,7 @@ func withSchedulerMetrics() []string {
 		"go_threads",
 	}
 }
+
+func withDebugMetrics() []string {
+	return withBaseMetrics([]string{})
+}

prometheus/collectors/go_collector_go121_test.go

@@ -151,7 +151,7 @@ func withSchedulerMetrics() []string {
 }
 
 func withDebugMetrics() []string {
-	return []string{
+	return withBaseMetrics([]string{
 		"go_godebug_non_default_behavior_execerrdot_events_total",
 		"go_godebug_non_default_behavior_gocachehash_events_total",
 		"go_godebug_non_default_behavior_gocachetest_events_total",
@@ -170,5 +170,5 @@ func withDebugMetrics() []string {
 		"go_godebug_non_default_behavior_x509sha1_events_total",
 		"go_godebug_non_default_behavior_x509usefallbackroots_events_total",
 		"go_godebug_non_default_behavior_zipinsecurepath_events_total",
-	}
+	})
 }

prometheus/collectors/go_collector_go122_test.go

@@ -166,7 +166,7 @@ func withSchedulerMetrics() []string {
 }
 
 func withDebugMetrics() []string {
-	return []string{
+	return withBaseMetrics([]string{
 		"go_godebug_non_default_behavior_execerrdot_events_total",
 		"go_godebug_non_default_behavior_gocachehash_events_total",
 		"go_godebug_non_default_behavior_gocachetest_events_total",
@@ -192,5 +192,5 @@ func withDebugMetrics() []string {
 		"go_godebug_non_default_behavior_x509usefallbackroots_events_total",
 		"go_godebug_non_default_behavior_x509usepolicies_events_total",
 		"go_godebug_non_default_behavior_zipinsecurepath_events_total",
-	}
+	})
 }

prometheus/collectors/go_collector_latest.go

@@ -37,6 +37,9 @@ var (
 	// MetricsScheduler allows only scheduler metrics to be collected from Go runtime.
 	// e.g. go_sched_goroutines_goroutines
 	MetricsScheduler = GoRuntimeMetricsRule{regexp.MustCompile(`^/sched/.*`)}
+	// MetricsDebug allows only debug metrics to be collected from Go runtime.
+	// e.g. go_godebug_non_default_behavior_gocachetest_events_total
+	MetricsDebug = GoRuntimeMetricsRule{regexp.MustCompile(`^/godebug/.*`)}
 )
 
 // WithGoCollectorMemStatsMetricsDisabled disables metrics that is gathered in runtime.MemStats structure such as:

prometheus/collectors/go_collector_latest_test.go

@@ -105,6 +105,11 @@ func TestGoCollectorAllowList(t *testing.T) {
 			rules:    []GoRuntimeMetricsRule{MetricsScheduler},
 			expected: withSchedulerMetrics(),
 		},
+		{
+			name:     "allow debug",
+			rules:    []GoRuntimeMetricsRule{MetricsDebug},
+			expected: withDebugMetrics(),
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			reg := prometheus.NewRegistry()