From 73a22b2e611647de04aa8d7fe910fd4657e6a9d8 Mon Sep 17 00:00:00 2001 From: xuzhonghu Date: Mon, 14 May 2018 16:19:38 +0800 Subject: [PATCH] Support dynamicly set logging verbosity --- .../src/k8s.io/apiserver/pkg/server/config.go | 12 ++ .../pkg/server/genericapiserver_test.go | 1 + .../k8s.io/apiserver/pkg/server/routes/BUILD | 1 + .../apiserver/pkg/server/routes/flags.go | 126 ++++++++++++++++++ 4 files changed, 140 insertions(+) create mode 100644 staging/src/k8s.io/apiserver/pkg/server/routes/flags.go diff --git a/staging/src/k8s.io/apiserver/pkg/server/config.go b/staging/src/k8s.io/apiserver/pkg/server/config.go index eb1c27d141..b472448134 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" ) @@ -575,6 +576,16 @@ 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 { @@ -583,6 +594,7 @@ 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 b68b30982e..650374434c 100644 --- a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go +++ b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver_test.go @@ -385,6 +385,7 @@ 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 e7ffd916bf..9dd3839564 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 0000000000..d40f11499b --- /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) +}