Golang FlagSet.Lookup方法代碼示例

func flagChanged(flags *flag.FlagSet, key string) bool {
	flag := flags.Lookup(key)
	if flag == nil {
		return false
	}
	return flag.Changed
}

func (c *Config) updateFlag(name string, flags *flag.FlagSet) {
	if f := flags.Lookup(name); f != nil {
		val := c.Viper.Get(name)
		strVal := fmt.Sprintf("%v", val)
		f.DefValue = strVal
	}
}

// TODO: should this override by destination path, or does swarm handle that?
func updateMounts(flags *pflag.FlagSet, mounts *[]swarm.Mount) {
	if !flags.Changed(flagMount) {
		return
	}

	*mounts = flags.Lookup(flagMount).Value.(*MountOpt).Value()
}

// findConfigurationConflicts iterates over the provided flags searching for
// duplicated configurations and unknown keys. It returns an error with all the conflicts if
// it finds any.
func findConfigurationConflicts(config map[string]interface{}, flags *pflag.FlagSet) error {
	// 1. Search keys from the file that we don't recognize as flags.
	unknownKeys := make(map[string]interface{})
	for key, value := range config {
		if flag := flags.Lookup(key); flag == nil {
			unknownKeys[key] = value
		}
	}

	// 2. Discard values that implement NamedOption.
	// Their configuration name differs from their flag name, like `labels` and `label`.
	if len(unknownKeys) > 0 {
		unknownNamedConflicts := func(f *pflag.Flag) {
			if namedOption, ok := f.Value.(opts.NamedOption); ok {
				if _, valid := unknownKeys[namedOption.Name()]; valid {
					delete(unknownKeys, namedOption.Name())
				}
			}
		}
		flags.VisitAll(unknownNamedConflicts)
	}

	if len(unknownKeys) > 0 {
		var unknown []string
		for key := range unknownKeys {
			unknown = append(unknown, key)
		}
		return fmt.Errorf("the following directives don't match any configuration option: %s", strings.Join(unknown, ", "))
	}

	var conflicts []string
	printConflict := func(name string, flagValue, fileValue interface{}) string {
		return fmt.Sprintf("%s: (from flag: %v, from file: %v)", name, flagValue, fileValue)
	}

	// 3. Search keys that are present as a flag and as a file option.
	duplicatedConflicts := func(f *pflag.Flag) {
		// search option name in the json configuration payload if the value is a named option
		if namedOption, ok := f.Value.(opts.NamedOption); ok {
			if optsValue, ok := config[namedOption.Name()]; ok {
				conflicts = append(conflicts, printConflict(namedOption.Name(), f.Value.String(), optsValue))
			}
		} else {
			// search flag name in the json configuration payload
			for _, name := range []string{f.Name, f.Shorthand} {
				if value, ok := config[name]; ok {
					conflicts = append(conflicts, printConflict(name, f.Value.String(), value))
					break
				}
			}
		}
	}

	flags.Visit(duplicatedConflicts)

	if len(conflicts) > 0 {
		return fmt.Errorf("the following directives are specified both as a flag and in the configuration file: %s", strings.Join(conflicts, ", "))
	}
	return nil
}

// Test if the named flag is a boolean flag.
func isBooleanFlag(name string, f *flag.FlagSet) bool {
	flag := f.Lookup(name)
	if flag == nil {
		return false
	}
	return flag.Value.Type() == "bool"
}

// Merge all of the flags from fsFrom into fsTo.
func AddPFlagSetToPFlagSet(fsFrom *pflag.FlagSet, fsTo *pflag.FlagSet) {
	fsFrom.VisitAll(func(f *pflag.Flag) {
		if fsTo.Lookup(f.Name) == nil {
			fsTo.AddFlag(f)
		}
	})
}

func mergeSwarm(swarm *swarm.Swarm, flags *pflag.FlagSet) error {
	spec := &swarm.Spec

	if flags.Changed(flagTaskHistoryLimit) {
		spec.Orchestration.TaskHistoryRetentionLimit, _ = flags.GetInt64(flagTaskHistoryLimit)
	}

	if flags.Changed(flagDispatcherHeartbeat) {
		if v, err := flags.GetDuration(flagDispatcherHeartbeat); err == nil {
			spec.Dispatcher.HeartbeatPeriod = uint64(v.Nanoseconds())
		}
	}

	if flags.Changed(flagCertExpiry) {
		if v, err := flags.GetDuration(flagCertExpiry); err == nil {
			spec.CAConfig.NodeCertExpiry = v
		}
	}

	if flags.Changed(flagExternalCA) {
		value := flags.Lookup(flagExternalCA).Value.(*ExternalCAOption)
		spec.CAConfig.ExternalCAs = value.Value()
	}

	return nil
}

func updateMounts(flags *pflag.FlagSet, mounts *[]mounttypes.Mount) error {

	mountsByTarget := map[string]mounttypes.Mount{}

	if flags.Changed(flagMountAdd) {
		values := flags.Lookup(flagMountAdd).Value.(*opts.MountOpt).Value()
		for _, mount := range values {
			if _, ok := mountsByTarget[mount.Target]; ok {
				return fmt.Errorf("duplicate mount target")
			}
			mountsByTarget[mount.Target] = mount
		}
	}

	// Add old list of mount points minus updated one.
	for _, mount := range *mounts {
		if _, ok := mountsByTarget[mount.Target]; !ok {
			mountsByTarget[mount.Target] = mount
		}
	}

	newMounts := []mounttypes.Mount{}

	toRemove := buildToRemoveSet(flags, flagMountRemove)

	for _, mount := range mountsByTarget {
		if _, exists := toRemove[mount.Target]; !exists {
			newMounts = append(newMounts, mount)
		}
	}
	sort.Sort(byMountSource(newMounts))
	*mounts = newMounts
	return nil
}

func mergeSwarm(swarm *swarm.Swarm, flags *pflag.FlagSet) error {
	spec := &swarm.Spec

	if flags.Changed("auto-accept") {
		value := flags.Lookup("auto-accept").Value.(*AutoAcceptOption)
		if len(spec.AcceptancePolicy.Policies) > 0 {
			spec.AcceptancePolicy.Policies = value.Policies(spec.AcceptancePolicy.Policies[0].Secret)
		} else {
			spec.AcceptancePolicy.Policies = value.Policies("")
		}
	}

	if flags.Changed("secret") {
		secret, _ := flags.GetString("secret")
		for _, policy := range spec.AcceptancePolicy.Policies {
			policy.Secret = secret
		}
	}

	if flags.Changed("task-history-limit") {
		spec.Orchestration.TaskHistoryRetentionLimit, _ = flags.GetInt64("task-history-limit")
	}

	if flags.Changed("dispatcher-heartbeat") {
		if v, err := flags.GetDuration("dispatcher-heartbeat"); err == nil {
			spec.Dispatcher.HeartbeatPeriod = uint64(v.Nanoseconds())
		}
	}

	return nil
}

// TODO: should this override by destination path, or does swarm handle that?
func mergeMounts(flags *pflag.FlagSet, mounts *[]swarm.Mount) {
	if !flags.Changed("mount") {
		return
	}

	values := flags.Lookup("mount").Value.(*MountOpt).Value()
	*mounts = append(*mounts, values...)
}

// getConflictFreeConfiguration loads the configuration from a JSON file.
// It compares that configuration with the one provided by the flags,
// and returns an error if there are conflicts.
func getConflictFreeConfiguration(configFile string, flags *pflag.FlagSet) (*Config, error) {
	b, err := ioutil.ReadFile(configFile)
	if err != nil {
		return nil, err
	}

	var config Config
	var reader io.Reader
	if flags != nil {
		var jsonConfig map[string]interface{}
		reader = bytes.NewReader(b)
		if err := json.NewDecoder(reader).Decode(&jsonConfig); err != nil {
			return nil, err
		}

		configSet := configValuesSet(jsonConfig)

		if err := findConfigurationConflicts(configSet, flags); err != nil {
			return nil, err
		}

		// Override flag values to make sure the values set in the config file with nullable values, like `false`,
		// are not overridden by default truthy values from the flags that were not explicitly set.
		// See https://github.com/docker/docker/issues/20289 for an example.
		//
		// TODO: Rewrite configuration logic to avoid same issue with other nullable values, like numbers.
		namedOptions := make(map[string]interface{})
		for key, value := range configSet {
			f := flags.Lookup(key)
			if f == nil { // ignore named flags that don't match
				namedOptions[key] = value
				continue
			}

			if _, ok := f.Value.(boolValue); ok {
				f.Value.Set(fmt.Sprintf("%v", value))
			}
		}
		if len(namedOptions) > 0 {
			// set also default for mergeVal flags that are boolValue at the same time.
			flags.VisitAll(func(f *pflag.Flag) {
				if opt, named := f.Value.(opts.NamedOption); named {
					v, set := namedOptions[opt.Name()]
					_, boolean := f.Value.(boolValue)
					if set && boolean {
						f.Value.Set(fmt.Sprintf("%v", v))
					}
				}
			})
		}

		config.valuesSet = configSet
	}

	reader = bytes.NewReader(b)
	err = json.NewDecoder(reader).Decode(&config)
	return &config, err
}

func flagsNotIntersected(l *flag.FlagSet, r *flag.FlagSet) *flag.FlagSet {
	f := flag.NewFlagSet("notIntersected", flag.ContinueOnError)
	l.VisitAll(func(flag *flag.Flag) {
		if r.Lookup(flag.Name) == nil {
			f.AddFlag(flag)
		}
	})
	return f
}

func confirmAction(flags *pflag.FlagSet) bool {
	if flags.Lookup(yesFlag).Value.String() == "false" {
		util.Info("Continue? [Y/n] ")
		cont := util.AskForConfirmation(true)
		if !cont {
			util.Fatal("Cancelled...\n")
			return false
		}
	}
	return true
}

// TODO: should this override by name, or does swarm handle that?
func mergePorts(flags *pflag.FlagSet, portConfig *[]swarm.PortConfig) {
	if !flags.Changed("ports") {
		return
	}

	values := flags.Lookup("ports").Value.(*opts.ListOpts).GetAll()
	ports, portBindings, _ := nat.ParsePortSpecs(values)

	for port := range ports {
		*portConfig = append(*portConfig, convertPortToPortConfig(port, portBindings)...)
	}
}

func updateLabels(flags *pflag.FlagSet, field *map[string]string) {
	if !flags.Changed(flagLabel) {
		return
	}

	values := flags.Lookup(flagLabel).Value.(*opts.ListOpts).GetAll()

	localLabels := map[string]string{}
	for key, value := range runconfigopts.ConvertKVStringsToMap(values) {
		localLabels[key] = value
	}
	*field = localLabels
}