gocollector: Add regex option to allow collection of debug runtime metrics

prometheus/collectors/gen_go_collector_set.go

@@ -128,21 +128,19 @@ 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)
  }
  }
 
  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
 }

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

@@ -112,3 +112,7 @@ func withSchedulerMetrics() []string {
  "go_sched_latencies_seconds",
  })
 }
+
+func withDebugMetrics() []string {
+ return withBaseMetrics([]string{})
+}

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()