Add more extensive runtime metrics

I've noticed that K8s and apiserver contains several metrics that etcd
does not have. This PR adds the missing metrics to the default
Prometheus registry.

Signed-off-by: Thomas Jungblut <[email protected]>

Author: tjungblu

server/etcdserver/metrics.go

@@ -19,6 +19,7 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
 	"go.uber.org/zap"
 
 	"go.etcd.io/etcd/api/v3/version"
@@ -162,6 +163,10 @@ var (
 )
 
 func init() {
+	// register more extensive go runtime metrics, for that we need to unregister the default metrics first
+	prometheus.Unregister(collectors.NewGoCollector())
+	prometheus.MustRegister(collectors.NewGoCollector(collectors.WithGoCollectorRuntimeMetrics(collectors.MetricsAll)))
+
 	prometheus.MustRegister(hasLeader)
 	prometheus.MustRegister(isLeader)
 	prometheus.MustRegister(leaderChanges)

tests/e2e/metrics_test.go

@@ -217,6 +217,7 @@ func TestNoMetricsMissing(t *testing.T) {
 			"etcd_snap_db_save_total_duration_seconds",
 			"etcd_snap_fsync_duration_seconds",
 			"go_gc_duration_seconds",
+			"go_gc_heap_allocs_by_size_bytes_bucket",
 			"go_gc_gogc_percent",
 			"go_gc_gomemlimit_bytes",
 			"go_goroutines",
@@ -244,6 +245,7 @@ func TestNoMetricsMissing(t *testing.T) {
 			"go_memstats_stack_sys_bytes",
 			"go_memstats_sys_bytes",
 			"go_sched_gomaxprocs_threads",
+			"go_sched_pauses_stopping_gc_seconds_bucket",
 			"go_threads",
 			"grpc_server_handled_total",
 			"grpc_server_msg_received_total",