Code optimization for add additional information to log trace in api server

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/BUILD

@@ -59,6 +59,7 @@ go_library(
         "patch.go",
         "response.go",
         "rest.go",
+        "trace_util.go",
         "update.go",
         "watch.go",
     ],

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/create.go

@@ -49,7 +49,7 @@ var namespaceGVK = schema.GroupVersionKind{Group: "", Version: "v1", Kind: "Name
 func createHandler(r rest.NamedCreater, scope *RequestScope, admit admission.Interface, includeName bool) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		// For performance tracking purposes.
-		trace := utiltrace.New("Create", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("Create", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		if isDryRun(req.URL) && !utilfeature.DefaultFeatureGate.Enabled(features.DryRun) {

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/delete.go

@@ -46,7 +46,7 @@ import (
 func DeleteResource(r rest.GracefulDeleter, allowsOptions bool, scope *RequestScope, admit admission.Interface) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		// For performance tracking purposes.
-		trace := utiltrace.New("Delete", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("Delete", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		if isDryRun(req.URL) && !utilfeature.DefaultFeatureGate.Enabled(features.DryRun) {
@@ -164,7 +164,7 @@ func DeleteResource(r rest.GracefulDeleter, allowsOptions bool, scope *RequestSc
 // DeleteCollection returns a function that will handle a collection deletion
 func DeleteCollection(r rest.CollectionDeleter, checkBody bool, scope *RequestScope, admit admission.Interface) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
-		trace := utiltrace.New("Delete", utiltrace.Field{"url", req.URL.Path})
+		trace := utiltrace.New("Delete", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		if isDryRun(req.URL) && !utilfeature.DefaultFeatureGate.Enabled(features.DryRun) {

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/get.go

@@ -51,7 +51,7 @@ type getterFunc func(ctx context.Context, name string, req *http.Request, trace
 // passed-in getterFunc to perform the actual get.
 func getResourceHandler(scope *RequestScope, getter getterFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
-		trace := utiltrace.New("Get", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("Get", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		namespace, name, err := scope.Namer.Name(req)
@@ -168,7 +168,7 @@ func getRequestOptions(req *http.Request, scope *RequestScope, into runtime.Obje
 func ListResource(r rest.Lister, rw rest.Watcher, scope *RequestScope, forceWatch bool, minRequestTimeout time.Duration) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		// For performance tracking purposes.
-		trace := utiltrace.New("List", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("List", traceFields(req)...)
 
 		namespace, err := scope.Namer.Namespace(req)
 		if err != nil {

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/helpers.go

@@ -58,3 +58,18 @@ func (lazy *lazyClientIP) String() string {
 	}
 	return "unknown"
 }
+
+// lazyAccept implements String() string and it will
+// calls http.Request Header.Get() lazily only when required.
+type lazyAccept struct {
+	req *http.Request
+}
+
+func (lazy *lazyAccept) String() string {
+	if lazy.req != nil {
+		accept := lazy.req.Header.Get("Accept")
+		return accept
+	}
+
+	return "unknown"
+}

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/helpers_test.go

@@ -57,3 +57,17 @@ func TestLazyClientIP(t *testing.T) {
 	clientIPWithoutReq := &lazyClientIP{}
 	assert.Equal(t, "unknown", fmt.Sprintf("%v", clientIPWithoutReq))
 }
+
+func TestLazyAccept(t *testing.T) {
+	req := &http.Request{}
+	req.Header = http.Header{}
+
+	accept := "application/json"
+	req.Header.Set("Accept", accept)
+
+	acceptWithReq := &lazyAccept{req}
+	assert.Equal(t, accept, fmt.Sprintf("%v", acceptWithReq))
+
+	acceptWithoutReq := &lazyAccept{}
+	assert.Equal(t, "unknown", fmt.Sprintf("%v", acceptWithoutReq))
+}

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/patch.go

@@ -61,7 +61,7 @@ const (
 func PatchResource(r rest.Patcher, scope *RequestScope, admit admission.Interface, patchTypes []string) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		// For performance tracking purposes.
-		trace := utiltrace.New("Patch", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("Patch", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		if isDryRun(req.URL) && !utilfeature.DefaultFeatureGate.Enabled(features.DryRun) {

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/trace_util.go

@@ -0,0 +1,32 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package handlers
+
+import (
+	"net/http"
+
+	utiltrace "k8s.io/utils/trace"
+)
+
+func traceFields(req *http.Request) []utiltrace.Field {
+	return []utiltrace.Field{
+		{Key: "url", Value: req.URL.Path},
+		{Key: "user-agent", Value: &lazyTruncatedUserAgent{req: req}},
+		{Key: "client", Value: &lazyClientIP{req: req}},
+		{Key: "accept", Value: &lazyAccept{req: req}},
+		{Key: "protocol", Value: req.Proto}}
+}

staging/src/k8s.io/apiserver/pkg/endpoints/handlers/update.go

@@ -46,7 +46,7 @@ import (
 func UpdateResource(r rest.Updater, scope *RequestScope, admit admission.Interface) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		// For performance tracking purposes.
-		trace := utiltrace.New("Update", utiltrace.Field{Key: "url", Value: req.URL.Path}, utiltrace.Field{Key: "user-agent", Value: &lazyTruncatedUserAgent{req}}, utiltrace.Field{Key: "client", Value: &lazyClientIP{req}})
+		trace := utiltrace.New("Update", traceFields(req)...)
 		defer trace.LogIfLong(500 * time.Millisecond)
 
 		if isDryRun(req.URL) && !utilfeature.DefaultFeatureGate.Enabled(features.DryRun) {