// AppsForPod returns the apps of the pod with the given uuid in the given data directory.
// If appName is non-empty, then only the app with the given name will be returned.
func AppsForPod(uuid, dataDir string, appName string) ([]*App, error) {
	p, err := pkgPod.PodFromUUIDString(dataDir, uuid)
	if err != nil {
		return nil, err
	}
	defer p.Close()

	_, podManifest, err := p.PodManifest()
	if err != nil {
		return nil, err
	}

	var apps []*App
	for _, ra := range podManifest.Apps {
		if appName != "" && appName != ra.Name.String() {
			continue
		}

		app, err := newApp(&ra, podManifest, p)
		if err != nil {
			fmt.Fprintf(os.Stderr, "Cannot get app status: %v", err)
			continue
		}

		apps = append(apps, app)
	}

	return apps, nil
}

func runStatus(cmd *cobra.Command, args []string) (exit int) {
	if len(args) != 1 {
		cmd.Usage()
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	if flagWait {
		if err := p.WaitExited(); err != nil {
			stderr.PrintE("unable to wait for pod", err)
			return 254
		}
	}

	if err = printStatus(p); err != nil {
		stderr.PrintE("unable to print status", err)
		return 254
	}

	return 0
}

func runAppStart(cmd *cobra.Command, args []string) (exit int) {
	if len(args) < 1 {
		stderr.Print("must provide the pod UUID")
		return 1
	}

	if flagAppName == "" {
		stderr.Print("must provide the app to start")
		return 1
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 1
	}
	defer p.Close()

	if p.State() != pkgPod.Running {
		stderr.Printf("pod %q isn't currently running", p.UUID)
		return 1
	}

	appName, err := types.NewACName(flagAppName)
	if err != nil {
		stderr.PrintE("invalid app name", err)
	}

	podPID, err := p.ContainerPid1()
	if err != nil {
		stderr.PrintE(fmt.Sprintf("unable to determine the pid for pod %q", p.UUID), err)
		return 1
	}

	cfg := stage0.CommonConfig{
		DataDir: getDataDir(),
		UUID:    p.UUID,
		Debug:   globalFlags.Debug,
	}

	scfg := stage0.StartConfig{
		CommonConfig: &cfg,
		PodPath:      p.Path(),
		AppName:      appName,
		PodPID:       podPID,
	}

	if globalFlags.Debug {
		stage0.InitDebug()
	}

	err = stage0.StartApp(scfg)
	if err != nil {
		stderr.PrintE("error starting app", err)
		return 1
	}

	return 0
}

func runStop(cmd *cobra.Command, args []string) (exit int) {
	var podUUIDs []string
	var errors int

	ret := 0
	switch {
	case len(args) == 0 && flagUUIDFile != "":
		podUUID, err := pkgPod.ReadUUIDFromFile(flagUUIDFile)
		if err != nil {
			stderr.PrintE("unable to resolve UUID from file", err)
			ret = 1
		} else {
			podUUIDs = append(podUUIDs, podUUID)
		}

	case len(args) > 0 && flagUUIDFile == "":
		podUUIDs = args

	default:
		cmd.Usage()
		return 254
	}

	for _, podUUID := range podUUIDs {
		p, err := pkgPod.PodFromUUIDString(getDataDir(), podUUID)
		if err != nil {
			errors++
			stderr.PrintE("cannot get pod", err)
			continue
		}

		if p.AfterRun() {
			stdout.Printf("pod %q is already stopped", p.UUID)
			continue
		}

		if p.State() != pkgPod.Running {
			stderr.Error(fmt.Errorf("pod %q is not running", p.UUID))
			errors++
			continue
		}

		if err := stage0.StopPod(p.Path(), flagForce, p.UUID); err == nil {
			stdout.Printf("%q", p.UUID)
		} else {
			stderr.PrintE(fmt.Sprintf("error stopping %q", p.UUID), err)
			errors++
		}
	}

	if errors > 0 {
		stderr.Error(fmt.Errorf("failed to stop %d pod(s)", errors))
		return 254
	}

	return ret
}

func StopApp(cfg StopConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod manifest"), err)
	}
	defer pod.Close()

	_, pm, err := pod.PodManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod manifest"), err)
	}

	var mutable bool
	ms, ok := pm.Annotations.Get("coreos.com/rkt/stage1/mutable")
	if ok {
		mutable, err = strconv.ParseBool(ms)
		if err != nil {
			return errwrap.Wrap(errors.New("error parsing mutable annotation"), err)
		}
	}

	if !mutable {
		return errors.New("immutable pod: cannot start application")
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	args := []string{
		fmt.Sprintf("--app=%s", cfg.AppName),
	}

	ce := CrossingEntrypoint{
		PodPath:        cfg.PodPath,
		PodPID:         cfg.PodPID,
		AppName:        cfg.AppName.String(),
		EntrypointName: appStopEntrypoint,
		EntrypointArgs: args,
		Interactive:    false,
	}
	if err := ce.Run(); err != nil {
		status, err := common.GetExitStatus(err)
		// exit status 5 comes from systemctl and means the unit doesn't exist
		if status == 5 {
			return fmt.Errorf("app %q is not running", app.Name)
		}

		return err
	}

	return nil
}

func StartApp(cfg StartConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod"), err)
	}
	defer pod.Close()

	_, pm, err := pod.PodManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod manifest"), err)
	}

	var mutable bool
	ms, ok := pm.Annotations.Get("coreos.com/rkt/stage1/mutable")
	if ok {
		mutable, err = strconv.ParseBool(ms)
		if err != nil {
			return errwrap.Wrap(errors.New("error parsing mutable annotation"), err)
		}
	}

	if !mutable {
		return errors.New("immutable pod: cannot start application")
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	args := []string{
		fmt.Sprintf("--app=%s", cfg.AppName),
	}

	if _, err := os.Create(common.AppStartedPath(cfg.PodPath, cfg.AppName.String())); err != nil {
		log.FatalE(fmt.Sprintf("error creating %s-started file", cfg.AppName.String()), err)
	}

	ce := CrossingEntrypoint{
		PodPath:        cfg.PodPath,
		PodPID:         cfg.PodPID,
		AppName:        cfg.AppName.String(),
		EntrypointName: appStartEntrypoint,
		EntrypointArgs: args,
		Interactive:    false,
	}
	if err := ce.Run(); err != nil {
		return err
	}

	return nil
}

func (s *v1AlphaAPIServer) InspectPod(ctx context.Context, request *v1alpha.InspectPodRequest) (*v1alpha.InspectPodResponse, error) {
	p, err := pkgPod.PodFromUUIDString(getDataDir(), request.Id)
	if err != nil {
		stderr.PrintE(fmt.Sprintf("failed to get pod %q", request.Id), err)
		return nil, err
	}
	defer p.Close()

	pod := s.getBasicPod(p)

	fillPodDetails(s.store, p, pod)

	return &v1alpha.InspectPodResponse{Pod: pod}, nil
}

func (s *v1AlphaAPIServer) constrainedGetLogs(request *v1alpha.GetLogsRequest, server v1alpha.PublicAPI_GetLogsServer) error {
	pod, err := pkgPod.PodFromUUIDString(getDataDir(), request.PodId)
	if err != nil {
		return err
	}
	defer pod.Close()

	path, err := pod.JournalLogPath()
	if _, err := os.Stat(path); os.IsNotExist(err) {
		return fmt.Errorf("logging unsupported for pod %q", request.PodId)
	}

	jconf := sdjournal.JournalReaderConfig{
		Path: path,
	}
	if request.AppName != "" {
		jconf.Matches = []sdjournal.Match{
			{
				Field: sdjournal.SD_JOURNAL_FIELD_SYSLOG_IDENTIFIER,
				Value: request.AppName,
			},
		}
	}
	if request.SinceTime != 0 {
		t := time.Unix(request.SinceTime, 0)
		jconf.Since = -time.Since(t)
	}
	if request.Lines != 0 {
		jconf.NumFromTail = uint64(request.Lines)
	}

	jr, err := sdjournal.NewJournalReader(jconf)
	if err != nil {
		return err
	}
	defer jr.Close()

	if request.Follow {
		return jr.Follow(nil, LogsStreamWriter{server: server})
	}

	data, err := ioutil.ReadAll(jr)
	if err != nil {
		return err
	}

	return server.Send(&v1alpha.GetLogsResponse{Lines: common.RemoveEmptyLines(string(data))})
}

func runStatus(cmd *cobra.Command, args []string) (exit int) {
	if len(args) != 1 {
		cmd.Usage()
		return 254
	}

	dWait, err := parseDuration(flagWait)
	if err != nil {
		cmd.Usage()
		return 254
	}

	dReady, err := parseDuration(flagWaitReady)
	if err != nil {
		cmd.Usage()
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	if dReady != 0 {
		if err := p.WaitReady(newContext(dReady)); err != nil {
			stderr.PrintE("error waiting for pod readiness", err)
			return 254
		}
	}

	if dWait != 0 {
		if err := p.WaitFinished(newContext(dWait)); err != nil {
			stderr.PrintE("error waiting for pod to finish", err)
			return 254
		}
	}

	if err = printStatus(p); err != nil {
		stderr.PrintE("unable to print status", err)
		return 254
	}

	return 0
}

func StopApp(cfg StopConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod manifest"), err)
	}
	defer pod.Close()

	pm, err := pod.SandboxManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("cannot stop application"), err)
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	args := []string{
		fmt.Sprintf("--debug=%t", cfg.Debug),
		fmt.Sprintf("--app=%s", cfg.AppName),
	}

	ce := CrossingEntrypoint{
		PodPath:        cfg.PodPath,
		PodPID:         cfg.PodPID,
		AppName:        cfg.AppName.String(),
		EntrypointName: appStopEntrypoint,
		EntrypointArgs: args,
		Interactive:    false,
	}
	if err := ce.Run(); err != nil {
		status, err := common.GetExitStatus(err)
		// exit status 5 comes from systemctl and means the unit doesn't exist
		if status == 5 {
			return fmt.Errorf("app %q is not running", app.Name)
		}

		return err
	}

	return nil
}

func StartApp(cfg StartConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod"), err)
	}
	defer pod.Close()

	pm, err := pod.SandboxManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("cannot start application"), err)
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	args := []string{
		fmt.Sprintf("--debug=%t", cfg.Debug),
		fmt.Sprintf("--app=%s", cfg.AppName),
	}

	if _, err := os.Create(common.AppStartedPath(cfg.PodPath, cfg.AppName.String())); err != nil {
		log.FatalE(fmt.Sprintf("error creating %s-started file", cfg.AppName.String()), err)
	}

	ce := CrossingEntrypoint{
		PodPath:        cfg.PodPath,
		PodPID:         cfg.PodPID,
		AppName:        cfg.AppName.String(),
		EntrypointName: appStartEntrypoint,
		EntrypointArgs: args,
		Interactive:    false,
	}
	if err := ce.Run(); err != nil {
		return err
	}

	return nil
}

func RmApp(cfg RmConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod"), err)
	}
	defer pod.Close()

	debug("locking sandbox manifest")
	if err := pod.ExclusiveLockManifest(); err != nil {
		return errwrap.Wrap(errors.New("failed to lock sandbox manifest"), err)
	}
	defer pod.UnlockManifest()

	pm, err := pod.SandboxManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("cannot remove application, sandbox validation failed"), err)
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	if cfg.PodPID > 0 {
		// Call app-stop and app-rm entrypoint only if the pod is still running.
		// Otherwise, there's not much we can do about it except unmounting/removing
		// the file system.
		args := []string{
			fmt.Sprintf("--debug=%t", cfg.Debug),
			fmt.Sprintf("--app=%s", cfg.AppName),
		}

		ce := CrossingEntrypoint{
			PodPath:        cfg.PodPath,
			PodPID:         cfg.PodPID,
			AppName:        cfg.AppName.String(),
			EntrypointName: appStopEntrypoint,
			EntrypointArgs: args,
			Interactive:    false,
		}
		if err := ce.Run(); err != nil {
			status, err := common.GetExitStatus(err)
			// ignore nonexistent units failing to stop. Exit status 5
			// comes from systemctl and means the unit doesn't exist
			if err != nil {
				return err
			} else if status != 5 {
				return fmt.Errorf("exit status %d", status)
			}
		}

		ce.EntrypointName = appRmEntrypoint
		if err := ce.Run(); err != nil {
			return err
		}
	}

	if cfg.UsesOverlay {
		treeStoreID, err := ioutil.ReadFile(common.AppTreeStoreIDPath(cfg.PodPath, *cfg.AppName))
		if err != nil {
			return err
		}

		appRootfs := common.AppRootfsPath(cfg.PodPath, *cfg.AppName)
		if err := syscall.Unmount(appRootfs, 0); err != nil {
			return err
		}

		ts := filepath.Join(cfg.PodPath, "overlay", string(treeStoreID))
		if err := os.RemoveAll(ts); err != nil {
			return errwrap.Wrap(errors.New("error removing app info directory"), err)
		}
	}

	appInfoDir := common.AppInfoPath(cfg.PodPath, *cfg.AppName)
	if err := os.RemoveAll(appInfoDir); err != nil {
		return errwrap.Wrap(errors.New("error removing app info directory"), err)
	}

	if err := os.RemoveAll(common.AppPath(cfg.PodPath, *cfg.AppName)); err != nil {
		return err
	}

	appStatusPath := filepath.Join(common.Stage1RootfsPath(cfg.PodPath), "rkt", "status", cfg.AppName.String())
	if err := os.Remove(appStatusPath); err != nil && !os.IsNotExist(err) {
		return err
	}

	envPath := filepath.Join(common.Stage1RootfsPath(cfg.PodPath), "rkt", "env", cfg.AppName.String())
	if err := os.Remove(envPath); err != nil && !os.IsNotExist(err) {
		return err
	}

	for i, app := range pm.Apps {
		if app.Name == *cfg.AppName {
			pm.Apps = append(pm.Apps[:i], pm.Apps[i+1:]...)
			break
		}
	}

//.........这里部分代码省略.........

func runAppAdd(cmd *cobra.Command, args []string) (exit int) {
	if len(args) < 2 {
		stderr.Print("must provide the pod UUID and an IMAGEID")
		return 254
	}

	err := parseApps(&rktApps, args[1:], cmd.Flags(), true)
	if err != nil {
		stderr.PrintE("error parsing app image arguments", err)
		return 254
	}

	if rktApps.Count() > 1 {
		stderr.Print("must give only one app")
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	if p.State() != pkgPod.Running {
		stderr.Printf("pod %q isn't currently running", p.UUID)
		return 254
	}

	if !p.IsSupervisorReady() {
		stderr.Printf("supervisor for pod %q is not yet ready", p.UUID)
		return 254
	}

	s, err := imagestore.NewStore(storeDir())
	if err != nil {
		stderr.PrintE("cannot open store", err)
		return 254
	}

	ts, err := treestore.NewStore(treeStoreDir(), s)
	if err != nil {
		stderr.PrintE("cannot open treestore", err)
		return 254
	}

	fn := &image.Finder{
		S:  s,
		Ts: ts,
		Ks: getKeystore(),

		StoreOnly: true,
		NoStore:   false,
	}

	img, err := fn.FindImage(args[1], "")
	if err != nil {
		stderr.PrintE("error finding images", err)
		return 254
	}

	podPID, err := p.ContainerPid1()
	if err != nil {
		stderr.PrintE(fmt.Sprintf("unable to determine the pid for pod %q", p.UUID), err)
		return 254
	}

	ccfg := stage0.CommonConfig{
		DataDir:   getDataDir(),
		Store:     s,
		TreeStore: ts,
		UUID:      p.UUID,
		Debug:     globalFlags.Debug,
	}

	rktgid, err := common.LookupGid(common.RktGroup)
	if err != nil {
		stderr.Printf("group %q not found, will use default gid when rendering images", common.RktGroup)
		rktgid = -1
	}

	cfg := stage0.AddConfig{
		CommonConfig: &ccfg,
		Image:        *img,
		Apps:         &rktApps,
		RktGid:       rktgid,
		UsesOverlay:  p.UsesOverlay(),
		PodPath:      p.Path(),
		PodPID:       podPID,
	}

	if globalFlags.Debug {
		stage0.InitDebug()
	}

	err = stage0.AddApp(cfg)
	if err != nil {
		stderr.PrintE("error adding app to pod", err)
		return 254
	}
//.........这里部分代码省略.........

func runRunPrepared(cmd *cobra.Command, args []string) (exit int) {
	if len(args) != 1 {
		cmd.Usage()
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	s, err := imagestore.NewStore(storeDir())
	if err != nil {
		stderr.PrintE("cannot open store", err)
		return 254
	}

	ts, err := treestore.NewStore(treeStoreDir(), s)
	if err != nil {
		stderr.PrintE("cannot open treestore", err)
		return 254
	}

	if p.State() != pkgPod.Prepared {
		stderr.Printf("pod %q is not prepared", p.UUID)
		return 254
	}

	_, manifest, err := p.PodManifest()
	if err != nil {
		stderr.PrintE("cannot read pod manifest", err)
		return 254
	}

	if flagInteractive {
		if len(manifest.Apps) > 1 {
			stderr.Print("interactive option only supports pods with one app")
			return 254
		}
	}

	// Make sure we have a metadata service available before we move to
	// run state so that the user can rerun the command without needing
	// to prepare the image again.
	if flagMDSRegister {
		if err := stage0.CheckMdsAvailability(); err != nil {
			stderr.Error(err)
			return 254
		}
	}

	if err := p.ToRun(); err != nil {
		stderr.PrintE("cannot transition to run", err)
		return 254
	}

	lfd, err := p.Fd()
	if err != nil {
		stderr.PrintE("unable to get lock fd", err)
		return 254
	}

	rktgid, err := common.LookupGid(common.RktGroup)
	if err != nil {
		stderr.Printf("group %q not found, will use default gid when rendering images", common.RktGroup)
		rktgid = -1
	}

	ovlOk := true
	if err := common.PathSupportsOverlay(getDataDir()); err != nil {
		if oerr, ok := err.(common.ErrOverlayUnsupported); ok {
			stderr.Printf("disabling overlay support: %q", oerr.Error())
			ovlOk = false
		} else {
			stderr.PrintE("error determining overlay support", err)
			return 254
		}
	}

	ovlPrep := p.UsesOverlay()

	// should not happen, maybe the data directory moved from an overlay-enabled fs to another location
	// between prepare and run-prepared
	if ovlPrep && !ovlOk {
		stderr.Print("unable to run prepared overlay-enabled pod: overlay not supported")
		return 254
	}

	DNSConfMode, DNSConfig, HostsEntries, err := parseDNSFlags(flagHostsEntries, flagDNS, flagDNSSearch, flagDNSOpt, flagDNSDomain)
	if err != nil {
		stderr.PrintE("error with dns flags", err)
		return 254
	}

	rcfg := stage0.RunConfig{
		CommonConfig: &stage0.CommonConfig{
			DataDir:   getDataDir(),
			Store:     s,
//.........这里部分代码省略.........

func runEnter(cmd *cobra.Command, args []string) (exit int) {
	if len(args) < 1 {
		cmd.Usage()
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	if p.State() != pkgPod.Running {
		stderr.Printf("pod %q isn't currently running", p.UUID)
		return 254
	}

	podPID, err := p.ContainerPid1()
	if err != nil {
		stderr.PrintE(fmt.Sprintf("unable to determine the pid for pod %q", p.UUID), err)
		return 254
	}

	appName, err := getAppName(p)
	if err != nil {
		stderr.PrintE("unable to determine app name", err)
		return 254
	}

	argv, err := getEnterArgv(p, args)
	if err != nil {
		stderr.PrintE("enter failed", err)
		return 254
	}

	s, err := imagestore.NewStore(storeDir())
	if err != nil {
		stderr.PrintE("cannot open store", err)
		return 254
	}

	ts, err := treestore.NewStore(treeStoreDir(), s)
	if err != nil {
		stderr.PrintE("cannot open store", err)
		return 254
	}

	stage1TreeStoreID, err := p.GetStage1TreeStoreID()
	if err != nil {
		stderr.PrintE("error getting stage1 treeStoreID", err)
		return 254
	}

	stage1RootFS := ts.GetRootFS(stage1TreeStoreID)

	if err = stage0.Enter(p.Path(), podPID, *appName, stage1RootFS, argv); err != nil {
		stderr.PrintE("enter failed", err)
		return 254
	}
	// not reached when stage0.Enter execs /enter
	return 0
}

func AddApp(cfg AddConfig) error {
	// there should be only one app in the config
	app := cfg.Apps.Last()
	if app == nil {
		return errors.New("no image specified")
	}

	am, err := cfg.Store.GetImageManifest(cfg.Image.String())
	if err != nil {
		return err
	}

	var appName *types.ACName
	if app.Name != "" {
		appName, err = types.NewACName(app.Name)
		if err != nil {
			return err
		}
	} else {
		appName, err = imageNameToAppName(am.Name)
		if err != nil {
			return err
		}
	}

	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod"), err)
	}
	defer pod.Close()

	debug("locking pod manifest")
	if err := pod.ExclusiveLockManifest(); err != nil {
		return errwrap.Wrap(errors.New("failed to lock pod manifest"), err)
	}
	defer pod.UnlockManifest()

	pm, err := pod.SandboxManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("cannot add application"), err)
	}

	if pm.Apps.Get(*appName) != nil {
		return fmt.Errorf("error: multiple apps with name %s", *appName)
	}

	if am.App == nil && app.Exec == "" {
		return fmt.Errorf("error: image %s has no app section and --exec argument is not provided", cfg.Image)
	}

	appInfoDir := common.AppInfoPath(cfg.PodPath, *appName)
	if err := os.MkdirAll(appInfoDir, common.DefaultRegularDirPerm); err != nil {
		return errwrap.Wrap(errors.New("error creating apps info directory"), err)
	}

	pcfg := PrepareConfig{
		CommonConfig: cfg.CommonConfig,
		PrivateUsers: user.NewBlankUidRange(),
	}

	if cfg.UsesOverlay {
		privateUsers, err := preparedWithPrivateUsers(cfg.PodPath)
		if err != nil {
			log.FatalE("error reading user namespace information", err)
		}

		if err := pcfg.PrivateUsers.Deserialize([]byte(privateUsers)); err != nil {
			return err
		}
	}

	treeStoreID, err := prepareAppImage(pcfg, *appName, cfg.Image, cfg.PodPath, cfg.UsesOverlay)
	if err != nil {
		return errwrap.Wrap(fmt.Errorf("error preparing image %s", cfg.Image), err)
	}

	rcfg := RunConfig{
		CommonConfig: cfg.CommonConfig,
		UseOverlay:   cfg.UsesOverlay,
		RktGid:       cfg.RktGid,
	}

	if err := setupAppImage(rcfg, *appName, cfg.Image, cfg.PodPath, cfg.UsesOverlay); err != nil {
		return fmt.Errorf("error setting up app image: %v", err)
	}

	if cfg.UsesOverlay {
		imgDir := filepath.Join(cfg.PodPath, "overlay", treeStoreID)
		if err := os.Chown(imgDir, -1, cfg.RktGid); err != nil {
			return err
		}
	}

	ra := schema.RuntimeApp{
		Name: *appName,
		App:  am.App,
		Image: schema.RuntimeImage{
			Name:   &am.Name,
			ID:     cfg.Image,
			Labels: am.Labels,
//.........这里部分代码省略.........

func runExport(cmd *cobra.Command, args []string) (exit int) {
	if len(args) != 2 {
		cmd.Usage()
		return 254
	}

	outACI := args[1]
	ext := filepath.Ext(outACI)
	if ext != schema.ACIExtension {
		stderr.Printf("extension must be %s (given %s)", schema.ACIExtension, outACI)
		return 254
	}

	p, err := pkgPod.PodFromUUIDString(getDataDir(), args[0])
	if err != nil {
		stderr.PrintE("problem retrieving pod", err)
		return 254
	}
	defer p.Close()

	state := p.State()
	if state != pkgPod.Exited && state != pkgPod.ExitedGarbage {
		stderr.Print("pod is not exited. Only exited pods can be exported")
		return 254
	}

	app, err := getApp(p)
	if err != nil {
		stderr.PrintE("unable to find app", err)
		return 254
	}

	root := common.AppPath(p.Path(), app.Name)
	manifestPath := filepath.Join(common.AppInfoPath(p.Path(), app.Name), aci.ManifestFile)
	if p.UsesOverlay() {
		tmpDir := filepath.Join(getDataDir(), "tmp")
		if err := os.MkdirAll(tmpDir, common.DefaultRegularDirPerm); err != nil {
			stderr.PrintE("unable to create temp directory", err)
			return 254
		}
		podDir, err := ioutil.TempDir(tmpDir, fmt.Sprintf("rkt-export-%s", p.UUID))
		if err != nil {
			stderr.PrintE("unable to create export temp directory", err)
			return 254
		}
		defer func() {
			if err := os.RemoveAll(podDir); err != nil {
				stderr.PrintE("problem removing temp directory", err)
				exit = 1
			}
		}()
		mntDir := filepath.Join(podDir, "rootfs")
		if err := os.Mkdir(mntDir, common.DefaultRegularDirPerm); err != nil {
			stderr.PrintE("unable to create rootfs directory inside temp directory", err)
			return 254
		}

		if err := mountOverlay(p, app, mntDir); err != nil {
			stderr.PrintE(fmt.Sprintf("couldn't mount directory at %s", mntDir), err)
			return 254
		}
		defer func() {
			if err := syscall.Unmount(mntDir, 0); err != nil {
				stderr.PrintE(fmt.Sprintf("error unmounting directory %s", mntDir), err)
				exit = 1
			}
		}()
		root = podDir
	} else {
		hasMPs, err := appHasMountpoints(p.Path(), app.Name)
		if err != nil {
			stderr.PrintE("error parsing mountpoints", err)
			return 254
		}
		if hasMPs {
			stderr.Printf("pod has remaining mountpoints. Only pods using overlayfs or with no mountpoints can be exported")
			return 254
		}
	}

	// Check for user namespace (--private-user), if in use get uidRange
	var uidRange *user.UidRange
	privUserFile := filepath.Join(p.Path(), common.PrivateUsersPreparedFilename)
	privUserContent, err := ioutil.ReadFile(privUserFile)
	if err == nil {
		uidRange = user.NewBlankUidRange()
		// The file was found, save uid & gid shift and count
		if err := uidRange.Deserialize(privUserContent); err != nil {
			stderr.PrintE(fmt.Sprintf("problem deserializing the content of %s", common.PrivateUsersPreparedFilename), err)
			return 254
		}
	}

	if err = buildAci(root, manifestPath, outACI, uidRange); err != nil {
		stderr.PrintE("error building aci", err)
		return 254
	}
	return 0
}

func RmApp(cfg RmConfig) error {
	pod, err := pkgPod.PodFromUUIDString(cfg.DataDir, cfg.UUID.String())
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod"), err)
	}
	defer pod.Close()

	debug("locking pod manifest")
	if err := pod.ExclusiveManifestLock(); err != nil {
		return errwrap.Wrap(errors.New("failed to lock pod manifest"), err)
	}
	defer pod.ManifestUnlock()

	_, pm, err := pod.PodManifest()
	if err != nil {
		return errwrap.Wrap(errors.New("error loading pod manifest"), err)
	}

	var mutable bool
	ms, ok := pm.Annotations.Get("coreos.com/rkt/stage1/mutable")
	if ok {
		mutable, err = strconv.ParseBool(ms)
		if err != nil {
			return errwrap.Wrap(errors.New("error parsing mutable annotation"), err)
		}
	}

	if !mutable {
		return errors.New("immutable pod: cannot remove application")
	}

	app := pm.Apps.Get(*cfg.AppName)
	if app == nil {
		return fmt.Errorf("error: nonexistent app %q", *cfg.AppName)
	}

	if cfg.PodPID > 0 {
		// Call app-stop and app-rm entrypoint only if the pod is still running.
		// Otherwise, there's not much we can do about it except unmounting/removing
		// the file system.
		args := []string{
			fmt.Sprintf("--app=%s", cfg.AppName),
		}

		ce := CrossingEntrypoint{
			PodPath:        cfg.PodPath,
			PodPID:         cfg.PodPID,
			AppName:        cfg.AppName.String(),
			EntrypointName: appStopEntrypoint,
			EntrypointArgs: args,
			Interactive:    false,
		}
		if err := ce.Run(); err != nil {
			status, err := common.GetExitStatus(err)
			// ignore nonexistent units failing to stop. Exit status 5
			// comes from systemctl and means the unit doesn't exist
			if err != nil {
				return err
			} else if status != 5 {
				return fmt.Errorf("exit status %d", status)
			}
		}

		ce.EntrypointName = appRmEntrypoint
		if err := ce.Run(); err != nil {
			return err
		}
	}

	if cfg.UsesOverlay {
		treeStoreID, err := ioutil.ReadFile(common.AppTreeStoreIDPath(cfg.PodPath, *cfg.AppName))
		if err != nil {
			return err
		}

		appRootfs := common.AppRootfsPath(cfg.PodPath, *cfg.AppName)
		if err := syscall.Unmount(appRootfs, 0); err != nil {
			return err
		}

		ts := filepath.Join(cfg.PodPath, "overlay", string(treeStoreID))
		if err := os.RemoveAll(ts); err != nil {
			return errwrap.Wrap(errors.New("error removing app info directory"), err)
		}
	}

	appInfoDir := common.AppInfoPath(cfg.PodPath, *cfg.AppName)
	if err := os.RemoveAll(appInfoDir); err != nil {
		return errwrap.Wrap(errors.New("error removing app info directory"), err)
	}

	if err := os.RemoveAll(common.AppPath(cfg.PodPath, *cfg.AppName)); err != nil {
		return err
	}

	appStatusPath := filepath.Join(common.Stage1RootfsPath(cfg.PodPath), "rkt", "status", cfg.AppName.String())
	if err := os.Remove(appStatusPath); err != nil && !os.IsNotExist(err) {
		return err
	}

//.........这里部分代码省略.........