mcs: fix double compression of prom handler (#6339)

ref prometheus/client_golang#622, ref #5895 Signed-off-by: Ryan Leung <[email protected]>
tikv · Apr 20, 2023 · 9078ea5 · 9078ea5
1 parent 3cc745a
commit 9078ea5
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Showing 5 changed files with 13 additions and 25 deletions.
diff --git a/pkg/mcs/resource_manager/server/apis/v1/api.go b/pkg/mcs/resource_manager/server/apis/v1/api.go
@@ -24,7 +24,6 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/joho/godotenv"
 	rmpb "github.com/pingcap/kvproto/pkg/resource_manager"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	rmserver "github.com/tikv/pd/pkg/mcs/resource_manager/server"
 	"github.com/tikv/pd/pkg/mcs/utils"
 	"github.com/tikv/pd/pkg/utils/apiutil"
@@ -77,7 +76,7 @@ func NewService(srv *rmserver.Service) *Service {
 		c.Next()
 	})
 	apiHandlerEngine.Use(multiservicesapi.ServiceRedirector())
-	apiHandlerEngine.GET("metrics", utils.PromHandler(promhttp.Handler()))
+	apiHandlerEngine.GET("metrics", utils.PromHandler())
 	endpoint := apiHandlerEngine.Group(APIPathPrefix)
 	s := &Service{
 		manager:          manager,

diff --git a/pkg/mcs/tso/server/apis/v1/api.go b/pkg/mcs/tso/server/apis/v1/api.go
@@ -22,7 +22,6 @@ import (
 	"github.com/gin-contrib/gzip"
 	"github.com/gin-gonic/gin"
 	"github.com/joho/godotenv"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	tsoserver "github.com/tikv/pd/pkg/mcs/tso/server"
 	"github.com/tikv/pd/pkg/mcs/utils"
 	"github.com/tikv/pd/pkg/tso"
@@ -82,7 +81,7 @@ func NewService(srv *tsoserver.Service) *Service {
 		c.Next()
 	})
 	apiHandlerEngine.Use(multiservicesapi.ServiceRedirector())
-	apiHandlerEngine.GET("metrics", utils.PromHandler(promhttp.Handler()))
+	apiHandlerEngine.GET("metrics", utils.PromHandler())
 	endpoint := apiHandlerEngine.Group(APIPathPrefix)
 	s := &Service{
 		srv:              srv,

diff --git a/pkg/mcs/utils/util.go b/pkg/mcs/utils/util.go
@@ -16,11 +16,12 @@ package utils
 
 import (
 	"context"
-	"net/http"
 	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/tikv/pd/pkg/utils/etcdutil"
 	"go.etcd.io/etcd/clientv3"
 )
@@ -50,8 +51,11 @@ func InitClusterID(ctx context.Context, client *clientv3.Client) (id uint64, err
 }
 
 // PromHandler is a handler to get prometheus metrics.
-func PromHandler(handler http.Handler) gin.HandlerFunc {
+func PromHandler() gin.HandlerFunc {
 	return func(c *gin.Context) {
-		handler.ServeHTTP(c.Writer, c.Request)
+		// register promhttp.HandlerOpts DisableCompression
+		promhttp.InstrumentMetricHandler(prometheus.DefaultRegisterer, promhttp.HandlerFor(prometheus.DefaultGatherer, promhttp.HandlerOpts{
+			DisableCompression: true,
+		})).ServeHTTP(c.Writer, c.Request)
 	}
 }
diff --git a/tests/integrations/mcs/resource_manager/server_test.go b/tests/integrations/mcs/resource_manager/server_test.go
@@ -15,8 +15,6 @@
 package resourcemanager_test
 
 import (
-	"bytes"
-	"compress/gzip"
 	"context"
 	"encoding/json"
 	"io"
@@ -101,13 +99,8 @@ func TestResourceManagerServer(t *testing.T) {
 		re.NoError(err)
 		defer resp.Body.Close()
 		re.Equal(http.StatusOK, resp.StatusCode)
-		respString, err := io.ReadAll(resp.Body)
-		re.NoError(err)
-		reader := bytes.NewReader(respString)
-		gzipReader, err := gzip.NewReader(reader)
-		re.NoError(err)
-		output, err := io.ReadAll(gzipReader)
+		respBytes, err := io.ReadAll(resp.Body)
 		re.NoError(err)
-		re.Contains(string(output), "resource_manager_server_info")
+		re.Contains(string(respBytes), "resource_manager_server_info")
 	}
 }
diff --git a/tests/integrations/mcs/tso/server_test.go b/tests/integrations/mcs/tso/server_test.go
@@ -15,8 +15,6 @@
 package tso
 
 import (
-	"bytes"
-	"compress/gzip"
 	"context"
 	"fmt"
 	"io"
@@ -364,12 +362,7 @@ func TestMetrics(t *testing.T) {
 	re.NoError(err)
 	defer resp.Body.Close()
 	re.Equal(http.StatusOK, resp.StatusCode)
-	respString, err := io.ReadAll(resp.Body)
+	respBytes, err := io.ReadAll(resp.Body)
 	re.NoError(err)
-	reader := bytes.NewReader(respString)
-	gzipReader, err := gzip.NewReader(reader)
-	re.NoError(err)
-	output, err := io.ReadAll(gzipReader)
-	re.NoError(err)
-	re.Contains(string(output), "tso_server_info")
+	re.Contains(string(respBytes), "tso_server_info")
 }