Add request body size metric

Change-Id: Ica5d9b5457d4f844c4500b2c05b2f0631c27454c

Kubernetes-commit: 43c95cbf0682895cf5bb79452b1f011123ac4513

pkg/endpoints/handlers/create.go

@@ -37,6 +37,7 @@ import (
 	"k8s.io/apiserver/pkg/audit"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
 	"k8s.io/apiserver/pkg/endpoints/handlers/finisher"
+	requestmetrics "k8s.io/apiserver/pkg/endpoints/handlers/metrics"
 	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
 	"k8s.io/apiserver/pkg/endpoints/request"
 	"k8s.io/apiserver/pkg/registry/rest"
@@ -86,7 +87,7 @@ func createHandler(r rest.NamedCreater, scope *RequestScope, admit admission.Int
 			return
 		}
 
-		body, err := limitedReadBody(req, scope.MaxRequestBodyBytes)
+		body, err := limitedReadBodyWithRecordMetric(ctx, req, scope.MaxRequestBodyBytes, scope.Resource.GroupResource().String(), requestmetrics.Create)
 		trace.Step("limitedReadBody done", utiltrace.Field{"len", len(body)}, utiltrace.Field{"err", err})
 		if err != nil {
 			scope.err(err, w, req)

pkg/endpoints/handlers/delete.go

@@ -33,6 +33,7 @@ import (
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/apiserver/pkg/audit"
 	"k8s.io/apiserver/pkg/endpoints/handlers/finisher"
+	requestmetrics "k8s.io/apiserver/pkg/endpoints/handlers/metrics"
 	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
 	"k8s.io/apiserver/pkg/endpoints/request"
 	"k8s.io/apiserver/pkg/registry/rest"
@@ -70,7 +71,7 @@ func DeleteResource(r rest.GracefulDeleter, allowsOptions bool, scope *RequestSc
 
 		options := &metav1.DeleteOptions{}
 		if allowsOptions {
-			body, err := limitedReadBody(req, scope.MaxRequestBodyBytes)
+			body, err := limitedReadBodyWithRecordMetric(ctx, req, scope.MaxRequestBodyBytes, scope.Resource.GroupResource().String(), requestmetrics.Patch)
 			if err != nil {
 				scope.err(err, w, req)
 				return

pkg/endpoints/handlers/metrics/metrics.go

@@ -17,9 +17,19 @@ limitations under the License.
 package metrics
 
 import (
+	"context"
 	"k8s.io/component-base/metrics"
 )
 
+type RequestBodyVerb string
+
+const (
+	Patch  RequestBodyVerb = "patch"
+	Delete RequestBodyVerb = "delete"
+	Update RequestBodyVerb = "update"
+	Create RequestBodyVerb = "create"
+)
+
 var (
 	RequestBodySizes = metrics.NewHistogramVec(
 		&metrics.HistogramOpts{
@@ -34,3 +44,7 @@ var (
 		[]string{"resource", "verb"},
 	)
 )
+
+func RecordRequestBodySize(ctx context.Context, resource string, verb RequestBodyVerb, size int) {
+	RequestBodySizes.WithContext(ctx).WithLabelValues(resource, string(verb)).Observe(float64(size))
+}

pkg/endpoints/handlers/patch.go

@@ -23,9 +23,9 @@ import (
 	"strings"
 	"time"
 
+	jsonpatch "github.com/evanphx/json-patch"
 	kjson "sigs.k8s.io/json"
 
-	jsonpatch "github.com/evanphx/json-patch"
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metainternalversionscheme "k8s.io/apimachinery/pkg/apis/meta/internalversion/scheme"
@@ -45,6 +45,7 @@ import (
 	"k8s.io/apiserver/pkg/authorization/authorizer"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
 	"k8s.io/apiserver/pkg/endpoints/handlers/finisher"
+	requestmetrics "k8s.io/apiserver/pkg/endpoints/handlers/metrics"
 	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
 	"k8s.io/apiserver/pkg/endpoints/request"
 	"k8s.io/apiserver/pkg/registry/rest"
@@ -98,7 +99,7 @@ func PatchResource(r rest.Patcher, scope *RequestScope, admit admission.Interfac
 			return
 		}
 
-		patchBytes, err := limitedReadBody(req, scope.MaxRequestBodyBytes)
+		patchBytes, err := limitedReadBodyWithRecordMetric(ctx, req, scope.MaxRequestBodyBytes, scope.Resource.GroupResource().String(), requestmetrics.Patch)
 		trace.Step("limitedReadBody done", utiltrace.Field{"len", len(patchBytes)}, utiltrace.Field{"err", err})
 		if err != nil {
 			scope.err(err, w, req)

pkg/endpoints/handlers/rest.go

@@ -41,6 +41,7 @@ import (
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
+	requestmetrics "k8s.io/apiserver/pkg/endpoints/handlers/metrics"
 	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
 	"k8s.io/apiserver/pkg/endpoints/metrics"
 	"k8s.io/apiserver/pkg/endpoints/request"
@@ -390,6 +391,15 @@ func limitedReadBody(req *http.Request, limit int64) ([]byte, error) {
 	return data, nil
 }
 
+func limitedReadBodyWithRecordMetric(ctx context.Context, req *http.Request, limit int64, resourceGroup string, verb requestmetrics.RequestBodyVerb) ([]byte, error) {
+	readBody, err := limitedReadBody(req, limit)
+	if err == nil {
+		// only record if we've read successfully
+		requestmetrics.RecordRequestBodySize(ctx, resourceGroup, verb, len(readBody))
+	}
+	return readBody, err
+}
+
 func isDryRun(url *url.URL) bool {
 	return len(url.Query()["dryRun"]) != 0
 }

pkg/endpoints/handlers/rest_test.go

@@ -168,7 +168,7 @@ func TestLimitedReadBody(t *testing.T) {
         apiserver_request_body_sizes_bucket{resource="resource.group",verb="create",le="2.95e+06"} 1
         apiserver_request_body_sizes_bucket{resource="resource.group",verb="create",le="3.05e+06"} 1
         apiserver_request_body_sizes_bucket{resource="resource.group",verb="create",le="+Inf"} 1
-        apiserver_request_body_sizes_sum{resource="resource.group",verb="create"} 3
+        apiserver_request_body_sizes_sum{resource="resource.group",verb="create"} 4
         apiserver_request_body_sizes_count{resource="resource.group",verb="create"} 1
 `,
 			expectedErr: false,
@@ -185,7 +185,7 @@ func TestLimitedReadBody(t *testing.T) {
 			if err != nil {
 				t.Errorf("err not expected: got %v", err)
 			}
-			_, err = limitedReadBody(context.Background(), req, tc.limit, "resource.group", "create")
+			_, err = limitedReadBodyWithRecordMetric(context.Background(), req, tc.limit, "resource.group", metrics.Create)
 			if tc.expectedErr {
 				if err == nil {
 					t.Errorf("err expected: got nil")

pkg/endpoints/handlers/update.go

@@ -35,6 +35,7 @@ import (
 	"k8s.io/apiserver/pkg/authorization/authorizer"
 	"k8s.io/apiserver/pkg/endpoints/handlers/fieldmanager"
 	"k8s.io/apiserver/pkg/endpoints/handlers/finisher"
+	requestmetrics "k8s.io/apiserver/pkg/endpoints/handlers/metrics"
 	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
 	"k8s.io/apiserver/pkg/endpoints/request"
 	"k8s.io/apiserver/pkg/registry/rest"
@@ -69,7 +70,7 @@ func UpdateResource(r rest.Updater, scope *RequestScope, admit admission.Interfa
 			return
 		}
 
-		body, err := limitedReadBody(req, scope.MaxRequestBodyBytes)
+		body, err := limitedReadBodyWithRecordMetric(ctx, req, scope.MaxRequestBodyBytes, scope.Resource.GroupResource().String(), requestmetrics.Update)
 		trace.Step("limitedReadBody done", utiltrace.Field{"len", len(body)}, utiltrace.Field{"err", err})
 		if err != nil {
 			scope.err(err, w, req)