add PromMetricsGinHandler

gin.go

@@ -13,54 +13,42 @@ import (
 	"github.com/gin-gonic/gin"
 	jsoniter "github.com/json-iterator/go"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.uber.org/zap"
 )
 
 var (
-	// GinPromNamespace gin prometheus namespace
-	GinPromNamespace = "logging_prom_gin"
-	// GinPromLabels gin prometheus labels
-	GinPromLabels = []string{
+	// prometheus namespace
+	promNamespace = "logging"
+	// gin prometheus labels
+	promGinLabels = []string{
 		"status_code",
 		"path",
 		"method",
 	}
 	promGinUptime = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
-			Namespace: GinPromNamespace,
-			Name:      "uptime",
-			Help:      "server uptime",
+			Namespace: promNamespace,
+			Name:      "server_uptime",
+			Help:      "gin server uptime in seconds",
 		}, nil,
 	)
 	promGinReqCount = prometheus.NewCounterVec(
 		prometheus.CounterOpts{
-			Namespace: GinPromNamespace,
-			Name:      "request_count",
-			Help:      "http request count",
-		}, GinPromLabels,
+			Namespace: promNamespace,
+			Name:      "req_count",
+			Help:      "gin server request count",
+		}, promGinLabels,
 	)
 	promGinReqLatency = prometheus.NewHistogramVec(
 		prometheus.HistogramOpts{
-			Namespace: GinPromNamespace,
-			Name:      "request_latency",
-			Help:      "http request latency in seconds",
-		}, GinPromLabels,
+			Namespace: promNamespace,
+			Name:      "req_latency",
+			Help:      "gin server request latency in seconds",
+		}, promGinLabels,
 	)
 )
 
-// registers the prometheus metrics
-func init() {
-	if err := prometheus.Register(promGinUptime); err != nil {
-		Error(nil, "Register prometheus gin uptime error:"+err.Error())
-	}
-	if err := prometheus.Register(promGinReqCount); err != nil {
-		Error(nil, "Register prometheus gin request count error:"+err.Error())
-	}
-	if err := prometheus.Register(promGinReqLatency); err != nil {
-		Error(nil, "Register prometheus gin request latency error:"+err.Error())
-	}
-}
-
 // GetGinTraceIDFromHeader 从 gin 的 request header 中获取 key 为 TraceIDKeyname 的值作为 traceid
 func GetGinTraceIDFromHeader(c *gin.Context) string {
 	return c.Request.Header.Get(string(TraceIDKeyname))
@@ -426,3 +414,29 @@ func (w responseBodyWriter) Write(b []byte) (int, error) {
 	w.body.Write(b)
 	return w.ResponseWriter.Write(b)
 }
+
+// PromMetricsGinHandler handler of the prometheus metrics exporter
+// not a middleware
+func PromMetricsGinHandler(collectors ...prometheus.Collector) gin.HandlerFunc {
+	if err := prometheus.Register(promGinUptime); err != nil {
+		Error(nil, "Register prometheus gin uptime error:"+err.Error())
+	}
+	if err := prometheus.Register(promGinReqCount); err != nil {
+		Error(nil, "Register prometheus gin request count error:"+err.Error())
+	}
+	if err := prometheus.Register(promGinReqLatency); err != nil {
+		Error(nil, "Register prometheus gin request latency error:"+err.Error())
+	}
+	for _, collector := range collectors {
+		if err := prometheus.Register(collector); err != nil {
+			Error(nil, "Register collector error:"+err.Error())
+		}
+	}
+	// uptime
+	go func() {
+		for range time.Tick(time.Second) {
+			promGinUptime.WithLabelValues().Inc()
+		}
+	}()
+	return gin.WrapH(promhttp.Handler())
+}

go.mod

@@ -5,15 +5,14 @@ go 1.13
 require (
 	github.com/getsentry/sentry-go v0.6.0
 	github.com/gin-gonic/gin v1.6.2
-	github.com/golang/protobuf v1.4.0 // indirect
 	github.com/jinzhu/gorm v1.9.12
-	github.com/json-iterator/go v1.1.9
+	github.com/json-iterator/go v1.1.10
 	github.com/mattn/go-sqlite3 v2.0.3+incompatible // indirect
 	github.com/natefinch/lumberjack v2.0.0+incompatible
 	github.com/pkg/errors v0.9.1 // indirect
+	github.com/prometheus/client_golang v1.7.1
 	github.com/rs/xid v1.2.1
 	go.uber.org/zap v1.15.0
-	golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f // indirect
 	golang.org/x/tools v0.0.0-20191112195655-aa38f8e97acc // indirect
 	google.golang.org/appengine v1.6.1 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect