공통 메트릭 추가

metric/metric.go

@@ -106,6 +106,7 @@ func (mc *metricCollection) metricWriter() {
 }
 
 var NewMetric func(MetricType, string, string, map[string]string) MetricWriter
+var ConcurrentUser = MetricWriterNil
 
 func init() {
 	NewMetric = func(MetricType, string, string, map[string]string) MetricWriter {
@@ -130,6 +131,7 @@ func init() {
 				logger.Println("metrics are going to be generated for houston")
 				go mc.metricWriter()
 				NewMetric = newMetricImpl
+				ConcurrentUser = NewMetric(MetricGuage, "concurrent_user", "concurrent user count", nil)
 			} else {
 				logger.Println("metrics are NOT going to be generated. parent is not houston :", filename, string(fn))
 			}
@@ -145,6 +147,15 @@ func newMetricImpl(mt MetricType, name string, help string, constLabels map[stri
 	hash := md5.New()
 	hash.Write([]byte(name))
 
+	if constLabels == nil {
+		constLabels = make(map[string]string)
+	}
+
+	hn, _ := os.Hostname()
+	sn := path.Base(os.Args[0])
+	constLabels["hostname"] = hn
+	constLabels["service"] = sn
+
 	key := hex.EncodeToString(hash.Sum(nil))[:metric_key_size]
 	temp, _ := json.Marshal(MetricDescription{
 		Key:         key,