fixup golang std metrics

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

prometheus.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"hash/fnv"
 	"io"
+	"regexp"
 	"sync"
 	"time"
 
@@ -279,8 +280,10 @@ func (m *prometheusMeter) Write(w io.Writer, opts ...meter.Option) error {
 	}
 
 	if options.WriteProcessMetrics || options.WriteFDMetrics {
-		c := collectors.NewProcessCollector(collectors.ProcessCollectorOpts{})
-		_ = m.set.Register(c)
+		pc := collectors.NewProcessCollector(collectors.ProcessCollectorOpts{})
+		_ = m.set.Register(pc)
+		gc := collectors.NewGoCollector(collectors.WithGoCollectorRuntimeMetrics(collectors.GoRuntimeMetricsRule{Matcher: regexp.MustCompile("/.*")}))
+		_ = m.set.Register(gc)
 	}
 
 	g, ok := m.set.(prometheus.Gatherer)

prometheus_test.go

@@ -11,6 +11,18 @@ import (
 	"go.unistack.org/micro/v3/meter/wrapper"
 )
 
+func TestStd(t *testing.T) {
+	m := NewMeter(meter.WriteProcessMetrics(true), meter.WriteFDMetrics(true))
+	if err := m.Init(); err != nil {
+		t.Fatal(err)
+	}
+	buf := bytes.NewBuffer(nil)
+	_ = m.Write(buf)
+	if !bytes.Contains(buf.Bytes(), []byte(`go_goroutine`)) {
+		t.Fatalf("invalid metrics output: %s", buf.Bytes())
+	}
+}
+
 func TestBuildName(t *testing.T) {
 	m := NewMeter()
 	check := `micro_foo{micro_aaa="b",micro_bar="baz",micro_ccc="d"}`