Add server Up state metrics

Author: WiFeng

metrics/metrics.go

@@ -47,6 +47,7 @@ func initPrometheus(ctx context.Context, serviceName string, cfg config.Promethe
 	skyprome.SetPromeCfg(cfg)
 	skyprome.SetPromeService(serviceName)
 
+	skyprome.UpInit()
 	skyprome.LogInit()
 	skyprome.HttpServerInit()
 	skyprome.HttpClientInit()

metrics/prometheus/up.go

@@ -0,0 +1,20 @@
+package prometheus
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+func UpInit() {
+	upCounter := promauto.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "srv_up",
+			Help: "The server up state",
+		},
+		[]string{"service"},
+	)
+	labels := prometheus.Labels{
+		"service": service,
+	}
+	upCounter.With(labels).Set(1)
+}