diff --git a/staging/src/k8s.io/apiserver/pkg/server/config.go b/staging/src/k8s.io/apiserver/pkg/server/config.go
index 75a2b5dcc56..41ae90af689 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/config.go
+++ b/staging/src/k8s.io/apiserver/pkg/server/config.go
@@ -65,6 +65,7 @@ import (
openapicommon "k8s.io/kube-openapi/pkg/common"
// install apis
+ "github.com/golang/glog"
_ "k8s.io/apiserver/pkg/apis/apiserver/install"
)
@@ -574,6 +575,16 @@ func installAPI(s *GenericAPIServer, c *Config) {
if c.EnableContentionProfiling {
goruntime.SetBlockProfileRate(1)
}
+ // so far, only logging related endpoints are considered valid to add for these debug flags.
+ routes.DebugFlags{}.Install(s.Handler.NonGoRestfulMux, "v", routes.StringFlagPutHandler(
+ routes.StringFlagSetterFunc(func(val string) (string, error) {
+ var level glog.Level
+ if err := level.Set(val); err != nil {
+ return "", fmt.Errorf("failed set glog.logging.verbosity %s: %v", val, err)
+ }
+ return "successfully set glog.logging.verbosity to " + val, nil
+ }),
+ ))
}
if c.EnableMetrics {
if c.EnableProfiling {
@@ -582,6 +593,7 @@ func installAPI(s *GenericAPIServer, c *Config) {
routes.DefaultMetrics{}.Install(s.Handler.NonGoRestfulMux)
}
}
+
routes.Version{Version: c.Version}.Install(s.Handler.GoRestfulContainer)
if c.EnableDiscovery {
diff --git a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go
index 8439d8cf75a..00a9f87fe3e 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go
+++ b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go
@@ -423,6 +423,7 @@ func TestNotRestRoutesHaveAuth(t *testing.T) {
{"/"},
{"/swagger-ui/"},
{"/debug/pprof/"},
+ {"/debug/flags/"},
{"/version"},
} {
resp := httptest.NewRecorder()
diff --git a/staging/src/k8s.io/apiserver/pkg/server/routes/BUILD b/staging/src/k8s.io/apiserver/pkg/server/routes/BUILD
index e7ffd916bfd..9dd38395648 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/routes/BUILD
+++ b/staging/src/k8s.io/apiserver/pkg/server/routes/BUILD
@@ -9,6 +9,7 @@ go_library(
name = "go_default_library",
srcs = [
"doc.go",
+ "flags.go",
"index.go",
"metrics.go",
"openapi.go",
diff --git a/staging/src/k8s.io/apiserver/pkg/server/routes/flags.go b/staging/src/k8s.io/apiserver/pkg/server/routes/flags.go
new file mode 100644
index 00000000000..d40f11499b3
--- /dev/null
+++ b/staging/src/k8s.io/apiserver/pkg/server/routes/flags.go
@@ -0,0 +1,126 @@
+/*
+Copyright 2018 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 routes
+
+import (
+ "fmt"
+ "html/template"
+ "io/ioutil"
+ "net/http"
+ "path"
+ "sync"
+
+ "github.com/golang/glog"
+
+ "k8s.io/apiserver/pkg/server/mux"
+)
+
+var (
+ lock = &sync.RWMutex{}
+ registeredFlags = map[string]debugFlag{}
+)
+
+// DebugFlags adds handlers for flags under /debug/flags.
+type DebugFlags struct {
+}
+
+// Install registers the APIServer's flags handler.
+func (f DebugFlags) Install(c *mux.PathRecorderMux, flag string, handler func(http.ResponseWriter, *http.Request)) {
+ c.UnlistedHandle("/debug/flags", http.HandlerFunc(f.Index))
+ c.UnlistedHandlePrefix("/debug/flags/", http.HandlerFunc(f.Index))
+
+ url := path.Join("/debug/flags", flag)
+ c.UnlistedHandleFunc(url, handler)
+
+ f.addFlag(flag)
+}
+
+// Index responds with the `/debug/flags` request.
+// For example, "/debug/flags/v" serves the "--v" flag.
+// Index responds to a request for "/debug/flags/" with an HTML page
+// listing the available flags.
+func (f DebugFlags) Index(w http.ResponseWriter, r *http.Request) {
+ lock.RLock()
+ defer lock.RUnlock()
+ if err := indexTmpl.Execute(w, registeredFlags); err != nil {
+ glog.Error(err)
+ }
+}
+
+var indexTmpl = template.Must(template.New("index").Parse(`
+
+/debug/flags/
+
+
+/debug/flags/
+
+flags:
+
+{{range .}}
+{{.Flag}}
+{{end}}
+
+
+full flags configurable
+
+
+`))
+
+type debugFlag struct {
+ Flag string
+}
+
+func (f DebugFlags) addFlag(flag string) {
+ lock.Lock()
+ defer lock.Unlock()
+ registeredFlags[flag] = debugFlag{flag}
+}
+
+// StringFlagSetterFunc is a func used for setting string type flag.
+type StringFlagSetterFunc func(string) (string, error)
+
+// StringFlagPutHandler wraps an http Handler to set string type flag.
+func StringFlagPutHandler(setter StringFlagSetterFunc) http.HandlerFunc {
+ return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+ switch {
+ case req.Method == "PUT":
+ body, err := ioutil.ReadAll(req.Body)
+ if err != nil {
+ writePlainText(http.StatusBadRequest, "error reading request body: "+err.Error(), w)
+ return
+ }
+ defer req.Body.Close()
+ response, err := setter(string(body))
+ if err != nil {
+ writePlainText(http.StatusBadRequest, err.Error(), w)
+ return
+ }
+ writePlainText(http.StatusOK, response, w)
+ return
+ default:
+ writePlainText(http.StatusNotAcceptable, "unsupported http method", w)
+ return
+ }
+ })
+}
+
+// writePlainText renders a simple string response.
+func writePlainText(statusCode int, text string, w http.ResponseWriter) {
+ w.Header().Set("Content-Type", "text/plain")
+ w.WriteHeader(statusCode)
+ fmt.Fprintln(w, text)
+}