/* 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" "k8s.io/klog/v2" "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 { klog.Error(err) } } var indexTmpl = template.Must(template.New("index").Parse(`
/debug/flags/
flags:

{{range .}}
{{.Flag}}
{{end}}

full flags configurable