diff --git a/staging/src/k8s.io/apiserver/pkg/server/config.go b/staging/src/k8s.io/apiserver/pkg/server/config.go index b572d335910..61a13ddd55c 100644 --- a/staging/src/k8s.io/apiserver/pkg/server/config.go +++ b/staging/src/k8s.io/apiserver/pkg/server/config.go @@ -126,6 +126,7 @@ type Config struct { EnableIndex bool EnableProfiling bool + DebugSocketPath string EnableDiscovery bool // Requires generic profiling enabled @@ -360,6 +361,7 @@ func NewConfig(codecs serializer.CodecFactory) *Config { EnableIndex: true, EnableDiscovery: true, EnableProfiling: true, + DebugSocketPath: "", EnableMetrics: true, MaxRequestsInFlight: 400, MaxMutatingRequestsInFlight: 200, @@ -631,6 +633,11 @@ func (c completedConfig) New(name string, delegationTarget DelegationTarget) (*G return c.BuildHandlerChainFunc(handler, c.Config) } + var debugSocket *routes.DebugSocket + if c.DebugSocketPath != "" { + debugSocket = routes.NewDebugSocket(c.DebugSocketPath) + } + apiServerHandler := NewAPIServerHandler(name, c.Serializer, handlerChainBuilder, delegationTarget.UnprotectedHandler()) s := &GenericAPIServer{ @@ -645,6 +652,7 @@ func (c completedConfig) New(name string, delegationTarget DelegationTarget) (*G EquivalentResourceRegistry: c.EquivalentResourceRegistry, HandlerChainWaitGroup: c.HandlerChainWaitGroup, Handler: apiServerHandler, + UnprotectedDebugSocket: debugSocket, listedPathProvider: apiServerHandler, @@ -914,6 +922,13 @@ func installAPI(s *GenericAPIServer, c *Config) { // so far, only logging related endpoints are considered valid to add for these debug flags. routes.DebugFlags{}.Install(s.Handler.NonGoRestfulMux, "v", routes.StringFlagPutHandler(logs.GlogSetter)) } + if s.UnprotectedDebugSocket != nil { + s.UnprotectedDebugSocket.InstallProfiling() + s.UnprotectedDebugSocket.InstallDebugFlag("v", routes.StringFlagPutHandler(logs.GlogSetter)) + if c.EnableContentionProfiling { + goruntime.SetBlockProfileRate(1) + } + } if c.EnableMetrics { if c.EnableProfiling { diff --git a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go index 2868187f012..7dad83f7e79 100644 --- a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go +++ b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go @@ -32,6 +32,7 @@ import ( "k8s.io/apimachinery/pkg/runtime" "k8s.io/apimachinery/pkg/runtime/schema" "k8s.io/apimachinery/pkg/runtime/serializer" + utilruntime "k8s.io/apimachinery/pkg/util/runtime" "k8s.io/apimachinery/pkg/util/sets" utilwaitgroup "k8s.io/apimachinery/pkg/util/waitgroup" "k8s.io/apimachinery/pkg/version" @@ -136,6 +137,10 @@ type GenericAPIServer struct { // Handler holds the handlers being used by this API server Handler *APIServerHandler + // UnprotectedDebugSocket is used to serve pprof information in a unix-domain socket. This socket is + // not protected by authentication/authorization. + UnprotectedDebugSocket *routes.DebugSocket + // listedPathProvider is a lister which provides the set of paths to show at / listedPathProvider routes.ListedPathProvider @@ -467,6 +472,14 @@ func (s preparedGenericAPIServer) Run(stopCh <-chan struct{}) error { // Clean up resources on shutdown. defer s.Destroy() + // If UDS profiling is enabled, start a local http server listening on that socket + if s.UnprotectedDebugSocket != nil { + go func() { + defer utilruntime.HandleCrash() + klog.Error(s.UnprotectedDebugSocket.Run(stopCh)) + }() + } + // spawn a new goroutine for closing the MuxAndDiscoveryComplete signal // registration happens during construction of the generic api server // the last server in the chain aggregates signals from the previous instances diff --git a/staging/src/k8s.io/apiserver/pkg/server/options/feature.go b/staging/src/k8s.io/apiserver/pkg/server/options/feature.go index e8a62418421..e87109bbd5a 100644 --- a/staging/src/k8s.io/apiserver/pkg/server/options/feature.go +++ b/staging/src/k8s.io/apiserver/pkg/server/options/feature.go @@ -25,6 +25,7 @@ import ( type FeatureOptions struct { EnableProfiling bool + DebugSocketPath string EnableContentionProfiling bool } @@ -33,6 +34,7 @@ func NewFeatureOptions() *FeatureOptions { return &FeatureOptions{ EnableProfiling: defaults.EnableProfiling, + DebugSocketPath: defaults.DebugSocketPath, EnableContentionProfiling: defaults.EnableContentionProfiling, } } @@ -46,6 +48,8 @@ func (o *FeatureOptions) AddFlags(fs *pflag.FlagSet) { "Enable profiling via web interface host:port/debug/pprof/") fs.BoolVar(&o.EnableContentionProfiling, "contention-profiling", o.EnableContentionProfiling, "Enable lock contention profiling, if profiling is enabled") + fs.StringVar(&o.DebugSocketPath, "debug-socket-path", o.DebugSocketPath, + "Use an unprotected (no authn/authz) unix-domain socket for profiling with the given path") } func (o *FeatureOptions) ApplyTo(c *server.Config) error { @@ -54,6 +58,7 @@ func (o *FeatureOptions) ApplyTo(c *server.Config) error { } c.EnableProfiling = o.EnableProfiling + c.DebugSocketPath = o.DebugSocketPath c.EnableContentionProfiling = o.EnableContentionProfiling return nil diff --git a/staging/src/k8s.io/apiserver/pkg/server/routes/debugsocket.go b/staging/src/k8s.io/apiserver/pkg/server/routes/debugsocket.go new file mode 100644 index 00000000000..e7297b35f33 --- /dev/null +++ b/staging/src/k8s.io/apiserver/pkg/server/routes/debugsocket.go @@ -0,0 +1,82 @@ +/* +Copyright 2022 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" + "net" + "net/http" + "net/http/pprof" + "os" + "path" +) + +// DebugSocket installs profiling and debugflag as a Unix-Domain socket. +type DebugSocket struct { + path string + mux *http.ServeMux +} + +// NewDebugSocket creates a new DebugSocket for the given path. +func NewDebugSocket(path string) *DebugSocket { + return &DebugSocket{ + path: path, + mux: http.NewServeMux(), + } +} + +// InstallProfiling installs profiling endpoints in the socket. +func (s *DebugSocket) InstallProfiling() { + s.mux.HandleFunc("/debug/pprof", redirectTo("/debug/pprof/")) + s.mux.HandleFunc("/debug/pprof/", pprof.Index) + s.mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline) + s.mux.HandleFunc("/debug/pprof/profile", pprof.Profile) + s.mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol) + s.mux.HandleFunc("/debug/pprof/trace", pprof.Trace) +} + +// InstallDebugFlag installs debug flag endpoints in the socket. +func (s *DebugSocket) InstallDebugFlag(flag string, handler func(http.ResponseWriter, *http.Request)) { + f := DebugFlags{} + s.mux.HandleFunc("/debug/flags", f.Index) + s.mux.HandleFunc("/debug/flags/", f.Index) + + url := path.Join("/debug/flags", flag) + s.mux.HandleFunc(url, handler) + + f.addFlag(flag) +} + +// Run starts the server and waits for stopCh to be closed to close the server. +func (s *DebugSocket) Run(stopCh <-chan struct{}) error { + if err := os.Remove(s.path); err != nil && !os.IsNotExist(err) { + return fmt.Errorf("failed to remove (%v): %v", s.path, err) + } + + l, err := net.Listen("unix", s.path) + if err != nil { + return fmt.Errorf("listen error (%v): %v", s.path, err) + } + defer l.Close() + + srv := http.Server{Handler: s.mux} + go func() { + <-stopCh + srv.Close() + }() + return srv.Serve(l) +}