Golang Command.Flags方法代碼示例

func runFetch(cmd *cobra.Command, args []string) (exit int) {
	if err := parseApps(&rktApps, args, cmd.Flags(), false); err != nil {
		stderr("fetch: unable to parse arguments: %v", err)
		return 1
	}

	if rktApps.Count() < 1 {
		stderr("fetch: must provide at least one image")
		return 1
	}

	if flagStoreOnly && flagNoStore {
		stderr("both --store-only and --no-store specified")
		return 1
	}

	s, err := store.NewStore(getDataDir())
	if err != nil {
		stderr("fetch: cannot open store: %v", err)
		return 1
	}
	ks := getKeystore()
	config, err := getConfig()
	if err != nil {
		stderr("fetch: cannot get configuration: %v", err)
		return 1
	}
	ft := &image.Fetcher{
		S:                  s,
		Ks:                 ks,
		Headers:            config.AuthPerHost,
		DockerAuth:         config.DockerCredentialsPerRegistry,
		InsecureFlags:      globalFlags.InsecureFlags,
		Debug:              globalFlags.Debug,
		TrustKeysFromHTTPS: globalFlags.TrustKeysFromHTTPS,

		StoreOnly: flagStoreOnly,
		NoStore:   flagNoStore,
		WithDeps:  true,
	}

	err = rktApps.Walk(func(app *apps.App) error {
		hash, err := ft.FetchImage(app.Image, app.Asc, app.ImType)
		if err != nil {
			return err
		}
		if !flagFullHash {
			hash = types.ShortHash(hash)
		}
		stdout(hash)
		return nil
	})
	if err != nil {
		stderr("%v", err)
		return 1
	}

	return
}

func runFetch(cmd *cobra.Command, args []string) (exit int) {
	if err := parseApps(&rktApps, args, cmd.Flags(), false); err != nil {
		stderr("fetch: unable to parse arguments: %v", err)
		return 1
	}

	if rktApps.Count() < 1 {
		stderr("fetch: must provide at least one image")
		return 1
	}

	if flagStoreOnly && flagNoStore {
		stderr("both --store-only and --no-store specified")
		return 1
	}

	s, err := store.NewStore(globalFlags.Dir)
	if err != nil {
		stderr("fetch: cannot open store: %v", err)
		return 1
	}
	ks := getKeystore()
	config, err := getConfig()
	if err != nil {
		stderr("fetch: cannot get configuration: %v", err)
		return 1
	}
	ft := &fetcher{
		imageActionData: imageActionData{
			s:                  s,
			ks:                 ks,
			headers:            config.AuthPerHost,
			dockerAuth:         config.DockerCredentialsPerRegistry,
			insecureSkipVerify: globalFlags.InsecureSkipVerify,
			debug:              globalFlags.Debug,
		},
		storeOnly: flagStoreOnly,
		noStore:   flagNoStore,
		withDeps:  true,
	}

	err = rktApps.Walk(func(app *apps.App) error {
		hash, err := ft.fetchImage(app.Image, app.Asc)
		if err != nil {
			return err
		}
		shortHash := types.ShortHash(hash)
		stdout(shortHash)
		return nil
	})
	if err != nil {
		stderr("%v", err)
		return 1
	}

	return
}

func usageFunc(cmd *cobra.Command) error {
	subCommands := getSubCommands(cmd)
	commandUsageTemplate.Execute(tabOut, struct {
		Executable  string
		Cmd         *cobra.Command
		CmdFlags    *pflag.FlagSet
		SubCommands []*cobra.Command
		Version     string
	}{
		cliName,
		cmd,
		cmd.Flags(),
		subCommands,
		version.Version,
	})
	tabOut.Flush()
	return nil
}

// getStage1Hash will try to fetch stage1 from store if it is a
// default one. If that fails it will try to get via usual fetching
// from disk or network.
//
// As a special case, if stage1 image path is a default and not
// overriden by --stage1-image flag and it is has no scheme, it will
// try to fetch it from two places on disk - from the path directly if
// it is absolute and then from the same directory where rkt binary
// resides.
//
// The passed command must have "stage1-image" string flag registered.
func getStage1Hash(s *store.Store, cmd *cobra.Command) (*types.Hash, error) {
	fn := &finder{
		imageActionData: imageActionData{
			s: s,
		},
		storeOnly: false,
		noStore:   false,
		withDeps:  false,
	}

	imageFlag := cmd.Flags().Lookup(stage1ImageFlagName)
	if imageFlag == nil {
		panic(fmt.Sprintf("Expected flag --%s to be registered in command %s", stage1ImageFlagName, cmd.Name()))
	}
	path := imageFlag.Value.String()
	if path == defaultStage1Image {
		return getDefaultStage1Hash(fn, imageFlag.Changed)
	}
	return getCustomStage1Hash(fn, path)
}

// getStage1Hash will try to fetch stage1 from store if it is a
// default one. If that fails it will try to get via usual fetching
// from disk or network.
//
// As a special case, if stage1 image path is a default and not
// overriden by --stage1-image flag and it is has no scheme, it will
// try to fetch it from two places on disk - from the path directly if
// it is absolute and then from the same directory where rkt binary
// resides.
//
// The passed command must have "stage1-image" string flag registered.
func getStage1Hash(s *store.Store, cmd *cobra.Command) (*types.Hash, error) {
	fn := &image.Finder{
		S:                  s,
		InsecureFlags:      globalFlags.InsecureFlags,
		TrustKeysFromHttps: globalFlags.TrustKeysFromHttps,

		StoreOnly: false,
		NoStore:   false,
		WithDeps:  false,
	}

	imageFlag := cmd.Flags().Lookup(stage1ImageFlagName)
	if imageFlag == nil {
		panic(fmt.Sprintf("Expected flag --%s to be registered in command %s", stage1ImageFlagName, cmd.Name()))
	}
	path := imageFlag.Value.String()
	if path == defaultStage1Image {
		return getDefaultStage1Hash(fn, imageFlag.Changed)
	}
	return getCustomStage1Hash(fn, path)
}

func runRun(cmd *cobra.Command, args []string) (exit int) {
	err := parseApps(&rktApps, args, cmd.Flags(), true)
	if err != nil {
		stderr("run: error parsing app image arguments: %v", err)
		return 1
	}

	if len(flagPorts) > 0 && !flagPrivateNet.Any() {
		stderr("--port flag requires --private-net")
		return 1
	}

	if len(flagPodManifest) > 0 && (len(flagVolumes) > 0 || len(flagPorts) > 0 || flagInheritEnv || !flagExplicitEnv.IsEmpty() || rktApps.Count() > 0 || flagLocal) {
		stderr("conflicting flags set with --pod-manifest (see --help)")
		return 1
	}

	if globalFlags.Dir == "" {
		log.Printf("dir unset - using temporary directory")
		var err error
		globalFlags.Dir, err = ioutil.TempDir("", "rkt")
		if err != nil {
			stderr("error creating temporary directory: %v", err)
			return 1
		}
	}

	if flagInteractive && rktApps.Count() > 1 {
		stderr("run: interactive option only supports one image")
		return 1
	}

	if rktApps.Count() < 1 && len(flagPodManifest) == 0 {
		stderr("run: must provide at least one image or specify the pod manifest")
		return 1
	}

	s, err := store.NewStore(globalFlags.Dir)
	if err != nil {
		stderr("run: cannot open store: %v", err)
		return 1
	}

	config, err := getConfig()
	if err != nil {
		stderr("run: cannot get configuration: %v", err)
		return 1
	}
	fn := &finder{
		imageActionData: imageActionData{
			s:                  s,
			headers:            config.AuthPerHost,
			dockerAuth:         config.DockerCredentialsPerRegistry,
			insecureSkipVerify: globalFlags.InsecureSkipVerify,
			debug:              globalFlags.Debug,
		},
		local:    flagLocal,
		withDeps: false,
	}
	s1img, err := fn.findImage(flagStage1Image, "", false)
	if err != nil {
		stderr("Error finding stage1 image %q: %v", flagStage1Image, err)
		return 1
	}

	fn.ks = getKeystore()
	fn.withDeps = true
	if err := fn.findImages(&rktApps); err != nil {
		stderr("%v", err)
		return 1
	}

	p, err := newPod()
	if err != nil {
		stderr("Error creating new pod: %v", err)
		return 1
	}

	processLabel, mountLabel, err := label.InitLabels(nil)
	if err != nil {
		stderr("Error initialising SELinux: %v", err)
		return 1
	}

	cfg := stage0.CommonConfig{
		MountLabel:   mountLabel,
		ProcessLabel: processLabel,
		Store:        s,
		Stage1Image:  *s1img,
		UUID:         p.uuid,
		Debug:        globalFlags.Debug,
	}

	pcfg := stage0.PrepareConfig{
		CommonConfig: cfg,
		UseOverlay:   !flagNoOverlay && common.SupportsOverlay(),
	}

	if len(flagPodManifest) > 0 {
		pcfg.PodManifest = flagPodManifest
//.........這裏部分代碼省略.........

func runPrepare(cmd *cobra.Command, args []string) (exit int) {
	var err error
	origStdout := os.Stdout
	if flagQuiet {
		if os.Stdout, err = os.Open("/dev/null"); err != nil {
			stderr("prepare: unable to open /dev/null")
			return 1
		}
	}

	if err = parseApps(&rktApps, args, cmd.Flags(), true); err != nil {
		stderr("prepare: error parsing app image arguments: %v", err)
		return 1
	}

	if len(flagPodManifest) > 0 && (len(flagVolumes) > 0 || len(flagPorts) > 0 || flagInheritEnv || !flagExplicitEnv.IsEmpty() || flagLocal) {
		stderr("prepare: conflicting flags set with --pod-manifest (see --help)")
		return 1
	}

	if rktApps.Count() < 1 && len(flagPodManifest) == 0 {
		stderr("prepare: must provide at least one image or specify the pod manifest")
		return 1
	}

	if globalFlags.Dir == "" {
		log.Printf("dir unset - using temporary directory")
		globalFlags.Dir, err = ioutil.TempDir("", "rkt")
		if err != nil {
			stderr("prepare: error creating temporary directory: %v", err)
			return 1
		}
	}

	s, err := store.NewStore(globalFlags.Dir)
	if err != nil {
		stderr("prepare: cannot open store: %v", err)
		return 1
	}

	config, err := getConfig()
	if err != nil {
		stderr("prepare: cannot get configuration: %v", err)
		return 1
	}
	fn := &finder{
		imageActionData: imageActionData{
			s:                  s,
			headers:            config.AuthPerHost,
			dockerAuth:         config.DockerCredentialsPerRegistry,
			insecureSkipVerify: globalFlags.InsecureSkipVerify,
			debug:              globalFlags.Debug,
		},
		local:    flagLocal,
		withDeps: false,
	}

	s1img, err := getStage1Hash(s, flagStage1Image)
	if err != nil {
		stderr("prepare: %v", err)
		return 1
	}

	fn.ks = getKeystore()
	fn.withDeps = true
	if err := fn.findImages(&rktApps); err != nil {
		stderr("%v", err)
		return 1
	}

	p, err := newPod()
	if err != nil {
		stderr("prepare: error creating new pod: %v", err)
		return 1
	}

	cfg := stage0.CommonConfig{
		Store:       s,
		Stage1Image: *s1img,
		UUID:        p.uuid,
		Debug:       globalFlags.Debug,
	}

	pcfg := stage0.PrepareConfig{
		CommonConfig: cfg,
		UseOverlay:   !flagNoOverlay && common.SupportsOverlay(),
	}

	if len(flagPodManifest) > 0 {
		pcfg.PodManifest = flagPodManifest
	} else {
		pcfg.Volumes = []types.Volume(flagVolumes)
		pcfg.Ports = []types.ExposedPort(flagPorts)
		pcfg.InheritEnv = flagInheritEnv
		pcfg.ExplicitEnv = flagExplicitEnv.Strings()
		pcfg.Apps = &rktApps
	}

	if err = stage0.Prepare(pcfg, p.path(), p.uuid); err != nil {
		stderr("prepare: error setting up stage0: %v", err)
//.........這裏部分代碼省略.........

func runRun(cmd *cobra.Command, args []string) (exit int) {
	privateUsers := uid.NewBlankUidRange()
	err := parseApps(&rktApps, args, cmd.Flags(), true)
	if err != nil {
		stderr("run: error parsing app image arguments: %v", err)
		return 1
	}

	if flagStoreOnly && flagNoStore {
		stderr("both --store-only and --no-store specified")
		return 1
	}

	if flagPrivateUsers {
		if !common.SupportsUserNS() {
			stderr("run: --private-users is not supported, kernel compiled without user namespace support")
			return 1
		}
		privateUsers.SetRandomUidRange(uid.DefaultRangeCount)
	}

	if len(flagPorts) > 0 && flagNet.None() {
		stderr("--port flag does not work with 'none' networking")
		return 1
	}
	if len(flagPorts) > 0 && flagNet.Host() {
		stderr("--port flag does not work with 'host' networking")
		return 1
	}

	if flagMDSRegister && flagNet.None() {
		stderr("--mds-register flag does not work with --net=none. Please use 'host', 'default' or an equivalent network")
		return 1
	}

	if len(flagPodManifest) > 0 && (len(flagPorts) > 0 || flagInheritEnv || !flagExplicitEnv.IsEmpty() || rktApps.Count() > 0 || flagStoreOnly || flagNoStore) {
		stderr("conflicting flags set with --pod-manifest (see --help)")
		return 1
	}

	if flagInteractive && rktApps.Count() > 1 {
		stderr("run: interactive option only supports one image")
		return 1
	}

	if rktApps.Count() < 1 && len(flagPodManifest) == 0 {
		stderr("run: must provide at least one image or specify the pod manifest")
		return 1
	}

	s, err := store.NewStore(globalFlags.Dir)
	if err != nil {
		stderr("run: cannot open store: %v", err)
		return 1
	}

	config, err := getConfig()
	if err != nil {
		stderr("run: cannot get configuration: %v", err)
		return 1
	}
	fn := &finder{
		imageActionData: imageActionData{
			s:                  s,
			headers:            config.AuthPerHost,
			dockerAuth:         config.DockerCredentialsPerRegistry,
			insecureSkipVerify: globalFlags.InsecureSkipVerify,
			debug:              globalFlags.Debug,
		},
		storeOnly: flagStoreOnly,
		noStore:   flagNoStore,
		withDeps:  false,
	}

	s1img, err := getStage1Hash(s, cmd)
	if err != nil {
		stderr("%v", err)
		return 1
	}

	fn.ks = getKeystore()
	fn.withDeps = true
	if err := fn.findImages(&rktApps); err != nil {
		stderr("%v", err)
		return 1
	}

	p, err := newPod()
	if err != nil {
		stderr("Error creating new pod: %v", err)
		return 1
	}

	// if requested, write out pod UUID early so "rkt rm" can
	// clean it up even if something goes wrong
	if flagUUIDFileSave != "" {
		if err := writeUUIDToFile(p.uuid, flagUUIDFileSave); err != nil {
			stderr("Error saving pod UUID to file: %v", err)
			return 1
		}
//.........這裏部分代碼省略.........

func runPrepare(cmd *cobra.Command, args []string) (exit int) {
	var err error
	origStdout := os.Stdout
	privateUsers := uid.NewBlankUidRange()
	if flagQuiet {
		if os.Stdout, err = os.Open("/dev/null"); err != nil {
			stderr("prepare: unable to open /dev/null: %v", err)
			return 1
		}
	}

	if flagStoreOnly && flagNoStore {
		stderr("both --store-only and --no-store specified")
		return 1
	}

	if flagPrivateUsers {
		if !common.SupportsUserNS() {
			stderr("prepare: --private-users is not supported, kernel compiled without user namespace support")
			return 1
		}
		privateUsers.SetRandomUidRange(uid.DefaultRangeCount)
	}

	if err = parseApps(&rktApps, args, cmd.Flags(), true); err != nil {
		stderr("prepare: error parsing app image arguments: %v", err)
		return 1
	}

	if len(flagPodManifest) > 0 && (len(flagPorts) > 0 || flagInheritEnv || !flagExplicitEnv.IsEmpty() || flagStoreOnly || flagNoStore) {
		stderr("prepare: conflicting flags set with --pod-manifest (see --help)")
		return 1
	}

	if rktApps.Count() < 1 && len(flagPodManifest) == 0 {
		stderr("prepare: must provide at least one image or specify the pod manifest")
		return 1
	}

	s, err := store.NewStore(getDataDir())
	if err != nil {
		stderr("prepare: cannot open store: %v", err)
		return 1
	}

	config, err := getConfig()
	if err != nil {
		stderr("prepare: cannot get configuration: %v", err)
		return 1
	}

	s1img, err := getStage1Hash(s, cmd)
	if err != nil {
		stderr("prepare: %v", err)
		return 1
	}

	fn := &image.Finder{
		S:                  s,
		Ks:                 getKeystore(),
		Headers:            config.AuthPerHost,
		DockerAuth:         config.DockerCredentialsPerRegistry,
		InsecureFlags:      globalFlags.InsecureFlags,
		Debug:              globalFlags.Debug,
		TrustKeysFromHttps: globalFlags.TrustKeysFromHttps,

		StoreOnly: flagStoreOnly,
		NoStore:   flagNoStore,
		WithDeps:  true,
	}
	if err := fn.FindImages(&rktApps); err != nil {
		stderr("prepare: %v", err)
		return 1
	}

	p, err := newPod()
	if err != nil {
		stderr("prepare: error creating new pod: %v", err)
		return 1
	}

	cfg := stage0.CommonConfig{
		Store:       s,
		Stage1Image: *s1img,
		UUID:        p.uuid,
		Debug:       globalFlags.Debug,
	}

	pcfg := stage0.PrepareConfig{
		CommonConfig: &cfg,
		UseOverlay:   !flagNoOverlay && common.SupportsOverlay(),
		PrivateUsers: privateUsers,
	}

	if len(flagPodManifest) > 0 {
		pcfg.PodManifest = flagPodManifest
	} else {
		pcfg.Ports = []types.ExposedPort(flagPorts)
		pcfg.InheritEnv = flagInheritEnv
		pcfg.ExplicitEnv = flagExplicitEnv.Strings()
//.........這裏部分代碼省略.........