package server import ( "context" "fmt" "log" "net" "net/http" "net/http/pprof" "os" "runtime" "strings" "sync" "syscall" "time" "github.com/containers/podman/v4/libpod" "github.com/containers/podman/v4/libpod/shutdown" "github.com/containers/podman/v4/pkg/api/handlers" "github.com/containers/podman/v4/pkg/api/server/idle" "github.com/containers/podman/v4/pkg/api/types" "github.com/containers/podman/v4/pkg/domain/entities" "github.com/coreos/go-systemd/v22/daemon" "github.com/gorilla/mux" "github.com/gorilla/schema" "github.com/sirupsen/logrus" ) type APIServer struct { http.Server // The HTTP work happens here net.Listener // mux for routing HTTP API calls to libpod routines *libpod.Runtime // Where the real work happens *schema.Decoder // Decoder for Query parameters to structs context.CancelFunc // Stop APIServer context.Context // Context to carry objects to handlers CorsHeaders string // Inject Cross-Origin Resource Sharing (CORS) headers PProfAddr string // Binding network address for pprof profiles idleTracker *idle.Tracker // Track connections to support idle shutdown } // Number of seconds to wait for next request, if exceeded shutdown server const ( DefaultCorsHeaders = "" DefaultServiceDuration = 300 * time.Second UnlimitedServiceDuration = 0 * time.Second ) // shutdownOnce ensures Shutdown() may safely be called from several go routines var shutdownOnce sync.Once // NewServer will create and configure a new API server with all defaults func NewServer(runtime *libpod.Runtime) (*APIServer, error) { return newServer(runtime, nil, entities.ServiceOptions{ CorsHeaders: DefaultCorsHeaders, Timeout: DefaultServiceDuration, }) } // NewServerWithSettings will create and configure a new API server using provided settings func NewServerWithSettings(runtime *libpod.Runtime, listener net.Listener, opts entities.ServiceOptions) (*APIServer, error) { return newServer(runtime, listener, opts) } func newServer(runtime *libpod.Runtime, listener net.Listener, opts entities.ServiceOptions) (*APIServer, error) { logrus.Infof("API service listening on %q. URI: %q", listener.Addr(), runtime.RemoteURI()) if opts.CorsHeaders == "" { logrus.Debug("CORS Headers were not set") } else { logrus.Debugf("CORS Headers were set to %q", opts.CorsHeaders) } logrus.Infof("API service listening on %q", listener.Addr()) router := mux.NewRouter().UseEncodedPath() tracker := idle.NewTracker(opts.Timeout) server := APIServer{ Server: http.Server{ ConnContext: func(ctx context.Context, c net.Conn) context.Context { return context.WithValue(ctx, types.ConnKey, c) }, ConnState: tracker.ConnState, ErrorLog: log.New(logrus.StandardLogger().Out, "", 0), Handler: router, IdleTimeout: opts.Timeout * 2, }, CorsHeaders: opts.CorsHeaders, Listener: listener, PProfAddr: opts.PProfAddr, idleTracker: tracker, } server.BaseContext = func(l net.Listener) context.Context { ctx := context.WithValue(context.Background(), types.DecoderKey, handlers.NewAPIDecoder()) ctx = context.WithValue(ctx, types.RuntimeKey, runtime) ctx = context.WithValue(ctx, types.IdleTrackerKey, tracker) return ctx } // Capture panics and print stack traces for diagnostics, // additionally process X-Reference-Id Header to support event correlation router.Use(panicHandler(), referenceIDHandler()) router.NotFoundHandler = http.HandlerFunc( func(w http.ResponseWriter, r *http.Request) { // We can track user errors... logrus.Infof("Failed Request: (%d:%s) for %s:'%s'", http.StatusNotFound, http.StatusText(http.StatusNotFound), r.Method, r.URL.String()) http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound) }, ) router.MethodNotAllowedHandler = http.HandlerFunc( func(w http.ResponseWriter, r *http.Request) { // We can track user errors... logrus.Infof("Failed Request: (%d:%s) for %s:'%s'", http.StatusMethodNotAllowed, http.StatusText(http.StatusMethodNotAllowed), r.Method, r.URL.String()) http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed) }, ) for _, fn := range []func(*mux.Router) error{ server.registerAuthHandlers, server.registerArchiveHandlers, server.registerContainersHandlers, server.registerDistributionHandlers, server.registerEventsHandlers, server.registerExecHandlers, server.registerGenerateHandlers, server.registerHealthCheckHandlers, server.registerImagesHandlers, server.registerInfoHandlers, server.registerManifestHandlers, server.registerMonitorHandlers, server.registerNetworkHandlers, server.registerPingHandlers, server.registerKubeHandlers, server.registerPluginsHandlers, server.registerPodsHandlers, server.registerSecretHandlers, server.registerSwaggerHandlers, server.registerSwarmHandlers, server.registerSystemHandlers, server.registerVersionHandlers, server.registerVolumeHandlers, } { if err := fn(router); err != nil { return nil, err } } if logrus.IsLevelEnabled(logrus.TraceLevel) { // If in trace mode log request and response bodies router.Use(loggingHandler()) _ = router.Walk(func(route *mux.Route, r *mux.Router, ancestors []*mux.Route) error { path, err := route.GetPathTemplate() if err != nil { path = "" } methods, err := route.GetMethods() if err != nil { methods = []string{""} } logrus.Tracef("Methods: %6s Path: %s", strings.Join(methods, ", "), path) return nil }) } return &server, nil } // setupSystemd notifies systemd API service is ready // If the NOTIFY_SOCKET is set, communicate the PID and readiness, and unset INVOCATION_ID // so conmon and containers are in the correct cgroup. func (s *APIServer) setupSystemd() { if _, found := os.LookupEnv("NOTIFY_SOCKET"); !found { return } payload := fmt.Sprintf("MAINPID=%d\n", os.Getpid()) payload += daemon.SdNotifyReady if sent, err := daemon.SdNotify(true, payload); err != nil { logrus.Error("API service failed to notify systemd of Conmon PID: " + err.Error()) } else if !sent { logrus.Warn("API service unable to successfully send SDNotify") } if err := os.Unsetenv("INVOCATION_ID"); err != nil { logrus.Error("API service failed unsetting INVOCATION_ID: " + err.Error()) } } // Serve starts responding to HTTP requests. func (s *APIServer) Serve() error { s.setupPprof() if err := shutdown.Register("service", func(sig os.Signal) error { return s.Shutdown(true) }); err != nil { return err } // Start the shutdown signal handler. if err := shutdown.Start(); err != nil { return err } go func() { <-s.idleTracker.Done() logrus.Debugf("API service(s) shutting down, idle for %ds", int(s.idleTracker.Duration.Seconds())) _ = s.Shutdown(false) }() // Before we start serving, ensure umask is properly set for container creation. _ = syscall.Umask(0o022) errChan := make(chan error, 1) s.setupSystemd() go func() { err := s.Server.Serve(s.Listener) if err != nil && err != http.ErrServerClosed { errChan <- fmt.Errorf("failed to start API service: %w", err) return } errChan <- nil }() return <-errChan } // setupPprof enables pprof default endpoints // Note: These endpoints and the podman flag --cpu-profile are mutually exclusive // // Examples: // #1 go tool pprof -http localhost:8889 localhost:8888/debug/pprof/heap?seconds=120 // Note: web page will only render after a sample has been recorded // #2 curl http://localhost:8888/debug/pprof/heap > heap.pprof && go tool pprof heap.pprof func (s *APIServer) setupPprof() { if s.PProfAddr == "" { return } logrus.Infof("pprof service listening on %q", s.PProfAddr) go func() { old := runtime.SetMutexProfileFraction(1) defer runtime.SetMutexProfileFraction(old) runtime.SetBlockProfileRate(1) defer runtime.SetBlockProfileRate(0) router := mux.NewRouter() router.PathPrefix("/debug/pprof/").HandlerFunc(pprof.Index) err := http.ListenAndServe(s.PProfAddr, router) if err != nil && err != http.ErrServerClosed { logrus.Warnf("pprof service failed: %v", err) } }() } // Shutdown is a clean shutdown waiting on existing clients func (s *APIServer) Shutdown(halt bool) error { switch { case halt: logrus.Debug("API service forced shutdown, ignoring timeout Duration") case s.idleTracker.Duration == UnlimitedServiceDuration: logrus.Debug("API service shutdown request ignored as timeout Duration is UnlimitedService") return nil } shutdownOnce.Do(func() { logrus.Debugf("API service shutdown, %d/%d connection(s)", s.idleTracker.ActiveConnections(), s.idleTracker.TotalConnections()) // Gracefully shutdown server(s), duration of wait same as idle window deadline := 1 * time.Second if s.idleTracker.Duration > 0 { deadline = s.idleTracker.Duration } ctx, cancel := context.WithTimeout(context.Background(), deadline) go func() { defer cancel() err := s.Server.Shutdown(ctx) if err != nil && err != context.Canceled && err != http.ErrServerClosed { logrus.Error("Failed to cleanly shutdown API service: " + err.Error()) } }() <-ctx.Done() }) return nil } // Close immediately stops responding to clients and exits func (s *APIServer) Close() error { return s.Server.Close() }