package main import ( "bytes" "errors" "fmt" "io/ioutil" "log" "os" "os/exec" "path/filepath" "time" "unsafe" "github.com/Microsoft/hcsshim/osversion" "github.com/sirupsen/logrus" "github.com/spf13/pflag" "golang.org/x/sys/windows" "golang.org/x/sys/windows/svc" "golang.org/x/sys/windows/svc/debug" "golang.org/x/sys/windows/svc/eventlog" "golang.org/x/sys/windows/svc/mgr" ) var ( flServiceName *string flRegisterService *bool flUnregisterService *bool flRunService *bool setStdHandle = windows.NewLazySystemDLL("kernel32.dll").NewProc("SetStdHandle") oldStderr windows.Handle panicFile *os.File service *handler ) const ( // These should match the values in event_messages.mc. eventInfo = 1 eventWarn = 1 eventError = 1 eventDebug = 2 eventPanic = 3 eventFatal = 4 eventExtraOffset = 10 // Add this to any event to get a string that supports extended data ) func installServiceFlags(flags *pflag.FlagSet) { flServiceName = flags.String("service-name", "docker", "Set the Windows service name") flRegisterService = flags.Bool("register-service", false, "Register the service and exit") flUnregisterService = flags.Bool("unregister-service", false, "Unregister the service and exit") flRunService = flags.Bool("run-service", false, "") _ = flags.MarkHidden("run-service") } type handler struct { tosvc chan bool fromsvc chan error daemonCli *DaemonCli } type etwHook struct { log *eventlog.Log } func (h *etwHook) Levels() []logrus.Level { return []logrus.Level{ logrus.PanicLevel, logrus.FatalLevel, logrus.ErrorLevel, logrus.WarnLevel, logrus.InfoLevel, logrus.DebugLevel, } } func (h *etwHook) Fire(e *logrus.Entry) error { var ( etype uint16 eid uint32 ) switch e.Level { case logrus.PanicLevel: etype = windows.EVENTLOG_ERROR_TYPE eid = eventPanic case logrus.FatalLevel: etype = windows.EVENTLOG_ERROR_TYPE eid = eventFatal case logrus.ErrorLevel: etype = windows.EVENTLOG_ERROR_TYPE eid = eventError case logrus.WarnLevel: etype = windows.EVENTLOG_WARNING_TYPE eid = eventWarn case logrus.InfoLevel: etype = windows.EVENTLOG_INFORMATION_TYPE eid = eventInfo case logrus.DebugLevel: etype = windows.EVENTLOG_INFORMATION_TYPE eid = eventDebug default: return errors.New("unknown level") } // If there is additional data, include it as a second string. exts := "" if len(e.Data) > 0 { fs := bytes.Buffer{} for k, v := range e.Data { fs.WriteString(k) fs.WriteByte('=') fmt.Fprint(&fs, v) fs.WriteByte(' ') } exts = fs.String()[:fs.Len()-1] eid += eventExtraOffset } if h.log == nil { fmt.Fprintf(os.Stderr, "%s [%s]\n", e.Message, exts) return nil } var ( ss [2]*uint16 err error ) ss[0], err = windows.UTF16PtrFromString(e.Message) if err != nil { return err } count := uint16(1) if exts != "" { ss[1], err = windows.UTF16PtrFromString(exts) if err != nil { return err } count++ } return windows.ReportEvent(h.log.Handle, etype, 0, eid, 0, count, 0, &ss[0], nil) } func getServicePath() (string, error) { p, err := exec.LookPath(os.Args[0]) if err != nil { return "", err } return filepath.Abs(p) } func registerService() error { p, err := getServicePath() if err != nil { return err } m, err := mgr.Connect() if err != nil { return err } defer m.Disconnect() depends := []string{} // This dependency is required on build 14393 (RS1) // it is added to the platform in newer builds if osversion.Build() == osversion.RS1 { depends = append(depends, "ConDrv") } c := mgr.Config{ ServiceType: windows.SERVICE_WIN32_OWN_PROCESS, StartType: mgr.StartAutomatic, ErrorControl: mgr.ErrorNormal, Dependencies: depends, DisplayName: "Docker Engine", } // Configure the service to launch with the arguments that were just passed. args := []string{"--run-service"} for _, a := range os.Args[1:] { if a != "--register-service" && a != "--unregister-service" { args = append(args, a) } } s, err := m.CreateService(*flServiceName, p, c, args...) if err != nil { return err } defer s.Close() // See http://stackoverflow.com/questions/35151052/how-do-i-configure-failure-actions-of-a-windows-service-written-in-go const ( scActionNone = 0 scActionRestart = 1 scActionReboot = 2 scActionRunCommand = 3 serviceConfigFailureActions = 2 ) type serviceFailureActions struct { ResetPeriod uint32 RebootMsg *uint16 Command *uint16 ActionsCount uint32 Actions uintptr } type scAction struct { Type uint32 Delay uint32 } t := []scAction{ {Type: scActionRestart, Delay: uint32(60 * time.Second / time.Millisecond)}, {Type: scActionRestart, Delay: uint32(60 * time.Second / time.Millisecond)}, {Type: scActionNone}, } lpInfo := serviceFailureActions{ResetPeriod: uint32(24 * time.Hour / time.Second), ActionsCount: uint32(3), Actions: uintptr(unsafe.Pointer(&t[0]))} err = windows.ChangeServiceConfig2(s.Handle, serviceConfigFailureActions, (*byte)(unsafe.Pointer(&lpInfo))) if err != nil { return err } return eventlog.Install(*flServiceName, p, false, eventlog.Info|eventlog.Warning|eventlog.Error) } func unregisterService() error { m, err := mgr.Connect() if err != nil { return err } defer m.Disconnect() s, err := m.OpenService(*flServiceName) if err != nil { return err } defer s.Close() eventlog.Remove(*flServiceName) err = s.Delete() if err != nil { return err } return nil } // initService is the entry point for running the daemon as a Windows // service. It returns an indication to stop (if registering/un-registering); // an indication of whether it is running as a service; and an error. func initService(daemonCli *DaemonCli) (bool, bool, error) { if *flUnregisterService { if *flRegisterService { return true, false, errors.New("--register-service and --unregister-service cannot be used together") } return true, false, unregisterService() } if *flRegisterService { return true, false, registerService() } if !*flRunService { return false, false, nil } interactive, err := svc.IsAnInteractiveSession() if err != nil { return false, false, err } h := &handler{ tosvc: make(chan bool), fromsvc: make(chan error), daemonCli: daemonCli, } var log *eventlog.Log if !interactive { log, err = eventlog.Open(*flServiceName) if err != nil { return false, false, err } } logrus.AddHook(&etwHook{log}) logrus.SetOutput(ioutil.Discard) service = h go func() { if interactive { err = debug.Run(*flServiceName, h) } else { err = svc.Run(*flServiceName, h) } h.fromsvc <- err }() // Wait for the first signal from the service handler. err = <-h.fromsvc if err != nil { return false, false, err } return false, true, nil } func (h *handler) started() error { // This must be delayed until daemonCli initializes Config.Root err := initPanicFile(filepath.Join(h.daemonCli.Config.Root, "panic.log")) if err != nil { return err } h.tosvc <- false return nil } func (h *handler) stopped(err error) { logrus.Debugf("Stopping service: %v", err) h.tosvc <- err != nil <-h.fromsvc } func (h *handler) Execute(_ []string, r <-chan svc.ChangeRequest, s chan<- svc.Status) (bool, uint32) { s <- svc.Status{State: svc.StartPending, Accepts: 0} // Unblock initService() h.fromsvc <- nil // Wait for initialization to complete. failed := <-h.tosvc if failed { logrus.Debug("Aborting service start due to failure during initialization") return true, 1 } s <- svc.Status{State: svc.Running, Accepts: svc.AcceptStop | svc.AcceptShutdown | svc.Accepted(windows.SERVICE_ACCEPT_PARAMCHANGE)} logrus.Debug("Service running") Loop: for { select { case failed = <-h.tosvc: break Loop case c := <-r: switch c.Cmd { case svc.Cmd(windows.SERVICE_CONTROL_PARAMCHANGE): h.daemonCli.reloadConfig() case svc.Interrogate: s <- c.CurrentStatus case svc.Stop, svc.Shutdown: s <- svc.Status{State: svc.StopPending, Accepts: 0} h.daemonCli.stop() } } } removePanicFile() if failed { return true, 1 } return false, 0 } func initPanicFile(path string) error { var err error panicFile, err = os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0o200) if err != nil { return err } st, err := panicFile.Stat() if err != nil { return err } // If there are contents in the file already, move the file out of the way // and replace it. if st.Size() > 0 { panicFile.Close() os.Rename(path, path+".old") panicFile, err = os.Create(path) if err != nil { return err } } // Update STD_ERROR_HANDLE to point to the panic file so that Go writes to // it when it panics. Remember the old stderr to restore it before removing // the panic file. sh := uint32(windows.STD_ERROR_HANDLE) h, err := windows.GetStdHandle(sh) if err != nil { return err } oldStderr = h r, _, err := setStdHandle.Call(uintptr(sh), uintptr(panicFile.Fd())) if r == 0 && err != nil { return err } // Reset os.Stderr to the panic file (so fmt.Fprintf(os.Stderr,...) actually gets redirected) os.Stderr = os.NewFile(uintptr(panicFile.Fd()), "/dev/stderr") // Force threads that panic to write to stderr (the panicFile handle now), otherwise it will go into the ether log.SetOutput(os.Stderr) return nil } func removePanicFile() { if st, err := panicFile.Stat(); err == nil { if st.Size() == 0 { sh := uint32(windows.STD_ERROR_HANDLE) setStdHandle.Call(uintptr(sh), uintptr(oldStderr)) panicFile.Close() os.Remove(panicFile.Name()) } } }