fix: metrics reduces labels (#1457)

Signed-off-by: Gaius <gaius.qi@gmail.com>

client/daemon/objectstorage/objectstorage.go

@@ -70,6 +70,10 @@ const (
 	OtelServiceName         = "dragonfly-dfdaemon-object-storage"
 )
 
+const (
+	RouterGroupBuckets = "/buckets"
+)
+
 var GinLogFileName = "gin-object-stroage.log"
 
 const (
@@ -147,6 +151,15 @@ func (o *objectStorage) initRouter(cfg *config.DaemonOption, logDir string) *gin
 
 	// Prometheus metrics
 	p := ginprometheus.NewPrometheus(PrometheusSubsystemName)
+	// Prometheus metrics need to reduce label,
+	// refer to https://prometheus.io/docs/practices/instrumentation/#do-not-overuse-labels.
+	p.ReqCntURLLabelMappingFn = func(c *gin.Context) string {
+		if strings.HasPrefix(c.Request.URL.Path, RouterGroupBuckets) {
+			return RouterGroupBuckets
+		}
+
+		return c.Request.URL.Path
+	}
 	p.Use(r)
 
 	// Opentelemetry
@@ -158,7 +171,7 @@ func (o *objectStorage) initRouter(cfg *config.DaemonOption, logDir string) *gin
 	r.GET("/healthy", o.getHealth)
 
 	// Buckets
-	b := r.Group("/buckets")
+	b := r.Group(RouterGroupBuckets)
 	b.HEAD(":id/objects/*object_key", o.headObject)
 	b.GET(":id/objects/*object_key", o.getObject)
 	b.DELETE(":id/objects/*object_key", o.destroyObject)

client/daemon/upload/upload_manager.go

@@ -27,6 +27,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/gin-gonic/gin"
 	"github.com/go-http-utils/headers"
@@ -45,6 +46,10 @@ const (
 	OtelServiceName         = "dragonfly-dfdaemon-upload"
 )
 
+const (
+	RouterGroupDownload = "/download"
+)
+
 var GinLogFileName = "gin-upload.log"
 
 // Manager is the interface used for upload task.
@@ -124,6 +129,15 @@ func (um *uploadManager) initRouter(cfg *config.DaemonOption, logDir string) *gi
 
 	// Prometheus metrics
 	p := ginprometheus.NewPrometheus(PrometheusSubsystemName)
+	// Prometheus metrics need to reduce label,
+	// refer to https://prometheus.io/docs/practices/instrumentation/#do-not-overuse-labels.
+	p.ReqCntURLLabelMappingFn = func(c *gin.Context) string {
+		if strings.HasPrefix(c.Request.URL.Path, RouterGroupDownload) {
+			return RouterGroupDownload
+		}
+
+		return c.Request.URL.Path
+	}
 	p.Use(r)
 
 	// Opentelemetry
@@ -135,7 +149,8 @@ func (um *uploadManager) initRouter(cfg *config.DaemonOption, logDir string) *gi
 	r.GET("/healthy", um.getHealth)
 
 	// Peer download task.
-	r.GET("/download/:task_prefix/:task_id", um.getDownload)
+	d := r.Group(RouterGroupDownload)
+	d.GET(":task_prefix/:task_id", um.getDownload)
 
 	return r
 }

manager/router/router.go

@@ -62,6 +62,12 @@ func Init(cfg *config.Config, logDir string, service service.Service, enforcer *
 
 	// Prometheus metrics
 	p := ginprometheus.NewPrometheus(PrometheusSubsystemName)
+	// URL removes query string.
+	// Prometheus metrics need to reduce label,
+	// refer to https://prometheus.io/docs/practices/instrumentation/#do-not-overuse-labels.
+	p.ReqCntURLLabelMappingFn = func(c *gin.Context) string {
+		return c.Request.URL.Path
+	}
 	p.Use(r)
 
 	// Opentelemetry