feat Prometheus

internal/global/global.go

@@ -1,7 +1,5 @@
 package global
 
-import "github.com/prometheus/client_golang/prometheus"
-
 const (
 	KeyGatewayAccessToken  = "gateway:token:access:%v"
 	KeyGatewayRefreshToken = "gateway:token:refresh:%v"
@@ -14,7 +12,3 @@ const (
 	MaxOnlineSize  = 100 // 最大在线人数
 	MaxQueueUpSize = 100 // 最大排队人数
 )
-
-var (
-	OnlineUsersGauge prometheus.Gauge
-)

internal/global/metric.go

@@ -0,0 +1,19 @@
+package global
+
+import (
+	"git.hlsq.asia/mmorpg/service-common/log"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	OnlineUsersGauge prometheus.Gauge
+)
+
+func init() {
+	log.Infof("Init prometheus metric...")
+	OnlineUsersGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "online_users",
+		Help: "Total number of online users",
+	})
+	prometheus.MustRegister(OnlineUsersGauge)
+}