package server import ( "context" "fmt" "log" "net" "net/http" "os" goRuntime "runtime" "strings" "sync" "syscall" "time" "github.com/containers/podman/v2/libpod" "github.com/containers/podman/v2/libpod/shutdown" "github.com/containers/podman/v2/pkg/api/handlers" "github.com/containers/podman/v2/pkg/api/server/idle" "github.com/coreos/go-systemd/v22/activation" "github.com/coreos/go-systemd/v22/daemon" "github.com/gorilla/mux" "github.com/gorilla/schema" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) type APIServer struct { http.Server // The HTTP work happens here *schema.Decoder // Decoder for Query parameters to structs context.Context // Context to carry objects to handlers *libpod.Runtime // Where the real work happens net.Listener // mux for routing HTTP API calls to libpod routines context.CancelFunc // Stop APIServer idleTracker *idle.Tracker // Track connections to support idle shutdown pprof *http.Server // Sidecar http server for providing performance data } // Number of seconds to wait for next request, if exceeded shutdown server const ( 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, DefaultServiceDuration, nil) } // NewServerWithSettings will create and configure a new API server using provided settings func NewServerWithSettings(runtime *libpod.Runtime, duration time.Duration, listener *net.Listener) (*APIServer, error) { return newServer(runtime, duration, listener) } func newServer(runtime *libpod.Runtime, duration time.Duration, listener *net.Listener) (*APIServer, error) { // If listener not provided try socket activation protocol if listener == nil { if _, found := os.LookupEnv("LISTEN_PID"); !found { return nil, errors.Errorf("Cannot create API Server, no listener provided and socket activation protocol is not active.") } listeners, err := activation.Listeners() if err != nil { return nil, errors.Wrap(err, "Cannot retrieve file descriptors from systemd") } if len(listeners) != 1 { return nil, errors.Errorf("Wrong number of file descriptors for socket activation protocol (%d != 1)", len(listeners)) } listener = &listeners[0] } logrus.Infof("API server listening on %q", (*listener).Addr()) router := mux.NewRouter().UseEncodedPath() idle := idle.NewTracker(duration) server := APIServer{ Server: http.Server{ Handler: router, ReadHeaderTimeout: 20 * time.Second, IdleTimeout: duration * 2, ConnState: idle.ConnState, ErrorLog: log.New(logrus.StandardLogger().Out, "", 0), }, Decoder: handlers.NewAPIDecoder(), idleTracker: idle, Listener: *listener, Runtime: runtime, } 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.registerPlayHandlers, server.registerPluginsHandlers, server.registerPodsHandlers, server.RegisterSwaggerHandlers, server.registerSwarmHandlers, server.registerSystemHandlers, server.registerVersionHandlers, server.registerVolumeHandlers, } { if err := fn(router); err != nil { return nil, err } } if logrus.IsLevelEnabled(logrus.DebugLevel) { router.Walk(func(route *mux.Route, r *mux.Router, ancestors []*mux.Route) error { // nolint path, err := route.GetPathTemplate() if err != nil { path = "" } methods, err := route.GetMethods() if err != nil { methods = []string{""} } logrus.Debugf("Methods: %6s Path: %s", strings.Join(methods, ", "), path) return nil }) } return &server, nil } // If the NOTIFY_SOCKET is set, communicate the PID and readiness, and // further unset NOTIFY_SOCKET to prevent containers from sending // messages and unset INVOCATION_ID so conmon and containers are in // the correct cgroup. func setupSystemd() { if len(os.Getenv("NOTIFY_SOCKET")) == 0 { return } payload := fmt.Sprintf("MAINPID=%d", os.Getpid()) payload += "\n" payload += daemon.SdNotifyReady if sent, err := daemon.SdNotify(true, payload); err != nil { logrus.Errorf("Error notifying systemd of Conmon PID: %s", err.Error()) } else if sent { logrus.Debugf("Notify sent successfully") } if err := os.Unsetenv("INVOCATION_ID"); err != nil { logrus.Errorf("Error unsetting INVOCATION_ID: %s", err.Error()) } } // Serve starts responding to HTTP requests. func (s *APIServer) Serve() error { setupSystemd() // Start the shutdown signal handler. if err := shutdown.Start(); err != nil { return err } if err := shutdown.Register("server", func(sig os.Signal) error { return s.Shutdown() }); err != nil { return err } errChan := make(chan error, 1) go func() { <-s.idleTracker.Done() logrus.Debugf("API Server idle for %s", s.idleTracker.Duration.Round(time.Second).String()) _ = s.Shutdown() }() if logrus.IsLevelEnabled(logrus.DebugLevel) { go func() { pprofMux := mux.NewRouter() pprofMux.PathPrefix("/debug/pprof").Handler(http.DefaultServeMux) goRuntime.SetMutexProfileFraction(1) goRuntime.SetBlockProfileRate(1) s.pprof = &http.Server{Addr: "localhost:8888", Handler: pprofMux} err := s.pprof.ListenAndServe() if err != nil && err != http.ErrServerClosed { logrus.Warn("Profiler Service failed: " + err.Error()) } }() } // Before we start serving, ensure umask is properly set for container // creation. _ = syscall.Umask(0022) go func() { err := s.Server.Serve(s.Listener) if err != nil && err != http.ErrServerClosed { errChan <- errors.Wrap(err, "failed to start API server") return } errChan <- nil }() return <-errChan } // Shutdown is a clean shutdown waiting on existing clients func (s *APIServer) Shutdown() error { if s.idleTracker.Duration == UnlimitedServiceDuration { logrus.Debug("APIServer.Shutdown ignored as Duration is UnlimitedService") return nil } shutdownOnce.Do(func() { if logrus.IsLevelEnabled(logrus.DebugLevel) { _, file, line, _ := goRuntime.Caller(1) logrus.Debugf("APIServer.Shutdown by %s:%d, %d/%d connection(s)", file, line, s.idleTracker.ActiveConnections(), s.idleTracker.TotalConnections()) go func() { ctx, cancel := context.WithTimeout(context.Background(), s.idleTracker.Duration) go func() { defer cancel() if err := s.pprof.Shutdown(ctx); err != nil { logrus.Warn( errors.Wrapf(err, "failed to cleanly shutdown pprof Server")) } }() <-ctx.Done() }() } // Gracefully shutdown server(s), duration of wait same as idle window ctx, cancel := context.WithTimeout(context.Background(), s.idleTracker.Duration) go func() { defer cancel() err := s.Server.Shutdown(ctx) if err != nil && err != context.Canceled && err != http.ErrServerClosed { logrus.Error( errors.Wrapf(err, "failed to cleanly shutdown APIServer")) } }() <-ctx.Done() }) return nil } // Close immediately stops responding to clients and exits func (s *APIServer) Close() error { return s.Server.Close() }