func (c *ImageMetadataCommand) Run(context *cmd.Context) error {
	if err := c.setParams(context); err != nil {
		return err
	}
	out := context.Stdout
	im := &imagemetadata.ImageMetadata{
		Id:   c.ImageId,
		Arch: c.Arch,
	}
	cloudSpec := simplestreams.CloudSpec{
		Region:   c.Region,
		Endpoint: c.Endpoint,
	}
	targetStorage, err := filestorage.NewFileStorageWriter(c.Dir)
	if err != nil {
		return err
	}
	err = imagemetadata.MergeAndWriteMetadata(c.Series, []*imagemetadata.ImageMetadata{im}, &cloudSpec, targetStorage)
	if err != nil {
		return fmt.Errorf("image metadata files could not be created: %v", err)
	}
	dir := context.AbsPath(c.Dir)
	dest := filepath.Join(dir, storage.BaseImagesPath, "streams", "v1")
	fmt.Fprintf(out, fmt.Sprintf(helpDoc, dest, dir, dir))
	return nil
}

func (c *DestroyEnvironmentCommand) Run(ctx *cmd.Context) (result error) {
	store, err := configstore.Default()
	if err != nil {
		return fmt.Errorf("cannot open environment info storage: %v", err)
	}
	environ, err := environs.NewFromName(c.envName, store)
	if err != nil {
		if environs.IsEmptyConfig(err) {
			// Delete the .jenv file and call it done.
			ctx.Infof("removing empty environment file")
			return environs.DestroyInfo(c.envName, store)
		}
		return err
	}
	if !c.assumeYes {
		fmt.Fprintf(ctx.Stdout, destroyEnvMsg, environ.Name(), environ.Config().Type())

		scanner := bufio.NewScanner(ctx.Stdin)
		scanner.Scan()
		err := scanner.Err()
		if err != nil && err != io.EOF {
			return fmt.Errorf("Environment destruction aborted: %s", err)
		}
		answer := strings.ToLower(scanner.Text())
		if answer != "y" && answer != "yes" {
			return errors.New("environment destruction aborted")
		}
	}
	// If --force is supplied, then don't attempt to use the API.
	// This is necessary to destroy broken environments, where the
	// API server is inaccessible or faulty.
	if !c.force {
		defer func() {
			if result == nil {
				return
			}
			logger.Errorf(`failed to destroy environment %q
        
If the environment is unusable, then you may run

    juju destroy-environment --force

to forcefully destroy the environment. Upon doing so, review
your environment provider console for any resources that need
to be cleaned up.

`, c.envName)
		}()
		apiclient, err := juju.NewAPIClientFromName(c.envName)
		if err != nil {
			return fmt.Errorf("cannot connect to API: %v", err)
		}
		defer apiclient.Close()
		err = apiclient.DestroyEnvironment()
		if err != nil && !params.IsCodeNotImplemented(err) {
			return fmt.Errorf("destroying environment: %v", err)
		}
	}
	return environs.Destroy(environ, store)
}

// addCharmViaAPI calls the appropriate client API calls to add the
// given charm URL to state. Also displays the charm URL of the added
// charm on stdout.
func addCharmViaAPI(client *api.Client, ctx *cmd.Context, curl *charm.URL, repo charm.Repository) (*charm.URL, error) {
	if curl.Revision < 0 {
		latest, err := charm.Latest(repo, curl)
		if err != nil {
			return nil, err
		}
		curl = curl.WithRevision(latest)
	}
	switch curl.Schema {
	case "local":
		ch, err := repo.Get(curl)
		if err != nil {
			return nil, err
		}
		stateCurl, err := client.AddLocalCharm(curl, ch)
		if err != nil {
			return nil, err
		}
		curl = stateCurl
	case "cs":
		err := client.AddCharm(curl)
		if err != nil {
			return nil, err
		}
	default:
		return nil, fmt.Errorf("unsupported charm URL schema: %q", curl.Schema)
	}
	ctx.Infof("Added charm %q to the environment.", curl)
	return curl, nil
}

// destroyPreparedEnviron destroys the environment and logs an error if it fails.
func destroyPreparedEnviron(ctx *cmd.Context, env environs.Environ, store configstore.Storage, err *error, action string) {
	if *err == nil {
		return
	}
	ctx.Infof("%s failed, destroying environment", action)
	if err := environs.Destroy(env, store); err != nil {
		logger.Errorf("%s failed, and the environment could not be destroyed: %v", action, err)
	}
}

func (c *SignMetadataCommand) Run(context *cmd.Context) error {
	loggo.RegisterWriter("signmetadata", cmd.NewCommandLogWriter("juju.plugins.metadata", context.Stdout, context.Stderr), loggo.INFO)
	defer loggo.RemoveWriter("signmetadata")
	keyData, err := ioutil.ReadFile(c.keyFile)
	if err != nil {
		return err
	}
	dir := context.AbsPath(c.dir)
	return process(dir, string(keyData), c.passphrase)
}

func (c *RpcCommand) Run(ctx *cmd.Context) error {
	if c.Value == "error" {
		return errors.New("blam")
	}
	if c.Slow {
		time.Sleep(testing.ShortWait)
		return nil
	}
	ctx.Stdout.Write([]byte("eye of newt\n"))
	ctx.Stderr.Write([]byte("toe of frog\n"))
	return ioutil.WriteFile(ctx.AbsPath("local"), []byte(c.Value), 0644)
}

// watchDebugLog1dot18 runs in case of an older API server and uses ssh
// but with server-side grep.
func (c *DebugLogCommand) watchDebugLog1dot18(ctx *cmd.Context) error {
	ctx.Infof("Server does not support new stream log, falling back to tail")
	ctx.Verbosef("filters are not supported with tail")
	sshCmd := &SSHCommand{}
	tailCmd := fmt.Sprintf("tail -n -%d -f %s", c.params.Backlog, DefaultLogLocation)
	// If the api doesn't support WatchDebugLog, then it won't be running in
	// HA either, so machine 0 is where it is all at.
	args := []string{"0", tailCmd}
	err := sshCmd.Init(args)
	if err != nil {
		return err
	}
	sshCmd.EnvName = c.EnvName
	return runSSHCommand(sshCmd, ctx)
}

func (c *ToolsMetadataCommand) Run(context *cmd.Context) error {
	loggo.RegisterWriter("toolsmetadata", cmd.NewCommandLogWriter("juju.environs.tools", context.Stdout, context.Stderr), loggo.INFO)
	defer loggo.RemoveWriter("toolsmetadata")
	if c.metadataDir == "" {
		c.metadataDir = osenv.JujuHome()
	} else {
		c.metadataDir = context.AbsPath(c.metadataDir)
	}

	sourceStorage, err := filestorage.NewFileStorageReader(c.metadataDir)
	if err != nil {
		return err
	}
	fmt.Fprintf(context.Stdout, "Finding tools in %s\n", c.metadataDir)
	const minorVersion = -1
	toolsList, err := envtools.ReadList(sourceStorage, version.Current.Major, minorVersion)
	if err == envtools.ErrNoTools {
		var source string
		source, err = envtools.ToolsURL(envtools.DefaultBaseURL)
		if err != nil {
			return err
		}
		sourceDataSource := simplestreams.NewURLDataSource("local source", source, utils.VerifySSLHostnames)
		toolsList, err = envtools.FindToolsForCloud(
			[]simplestreams.DataSource{sourceDataSource}, simplestreams.CloudSpec{},
			version.Current.Major, minorVersion, coretools.Filter{})
	}
	if err != nil {
		return err
	}

	targetStorage, err := filestorage.NewFileStorageWriter(c.metadataDir)
	if err != nil {
		return err
	}
	writeMirrors := envtools.DoNotWriteMirrors
	if c.public {
		writeMirrors = envtools.WriteMirrors
	}
	return mergeAndWriteMetadata(targetStorage, toolsList, writeMirrors)
}

func (c *DeployCommand) Run(ctx *cmd.Context) error {
	client, err := juju.NewAPIClientFromName(c.EnvName)
	if err != nil {
		return err
	}
	defer client.Close()

	attrs, err := client.EnvironmentGet()
	if err != nil {
		return err
	}
	conf, err := config.New(config.NoDefaults, attrs)
	if err != nil {
		return err
	}

	curl, err := resolveCharmURL(c.CharmName, client, conf)
	if err != nil {
		return err
	}

	repo, err := charm.InferRepository(curl.Reference, ctx.AbsPath(c.RepoPath))
	if err != nil {
		return err
	}

	repo = config.SpecializeCharmRepo(repo, conf)

	curl, err = addCharmViaAPI(client, ctx, curl, repo)
	if err != nil {
		return err
	}

	if c.BumpRevision {
		ctx.Infof("--upgrade (or -u) is deprecated and ignored; charms are always deployed with a unique revision.")
	}
	var includeNetworks []string
	var excludeNetworks []string
	haveNetworks := false
	if c.Networks != "" {
		includeNetworks = parseNetworks(c.Networks)
		haveNetworks = true
	}
	if c.ExcludeNetworks != "" {
		excludeNetworks = parseNetworks(c.ExcludeNetworks)
		haveNetworks = true
	}
	if haveNetworks {
		env, err := environs.New(conf)
		if err != nil {
			return err
		}
		if !env.SupportNetworks() {
			return errors.New("cannot use --networks/--exclude-networks: not supported by the environment")
		}
	}

	charmInfo, err := client.CharmInfo(curl.String())
	if err != nil {
		return err
	}

	numUnits := c.NumUnits
	if charmInfo.Meta.Subordinate {
		if !constraints.IsEmpty(&c.Constraints) {
			return errors.New("cannot use --constraints with subordinate service")
		}
		if numUnits == 1 && c.ToMachineSpec == "" {
			numUnits = 0
		} else {
			return errors.New("cannot use --num-units or --to with subordinate service")
		}
	}
	serviceName := c.ServiceName
	if serviceName == "" {
		serviceName = charmInfo.Meta.Name
	}

	var configYAML []byte
	if c.Config.Path != "" {
		configYAML, err = c.Config.Read(ctx)
		if err != nil {
			return err
		}
	}
	err = client.ServiceDeployWithNetworks(
		curl.String(),
		serviceName,
		numUnits,
		string(configYAML),
		c.Constraints,
		c.ToMachineSpec,
		includeNetworks,
		excludeNetworks,
	)
	if params.IsCodeNotImplemented(err) {
		if haveNetworks {
			return errors.New("cannot use --networks/--exclude-networks: not supported by the API server")
		}
		err = client.ServiceDeploy(
//.........这里部分代码省略.........

// Run connects to the environment specified on the command line and bootstraps
// a juju in that environment if none already exists. If there is as yet no environments.yaml file,
// the user is informed how to create one.
func (c *BootstrapCommand) Run(ctx *cmd.Context) (resultErr error) {
	bootstrapFuncs := getBootstrapFuncs()

	if len(c.seriesOld) > 0 {
		fmt.Fprintln(ctx.Stderr, "Use of --series is deprecated. Please use --upload-series instead.")
	}

	environ, cleanup, err := environFromName(ctx, c.EnvName, &resultErr, "Bootstrap")
	if err != nil {
		return err
	}
	validator, err := environ.ConstraintsValidator()
	if err != nil {
		return err
	}
	unsupported, err := validator.Validate(c.Constraints)
	if len(unsupported) > 0 {
		logger.Warningf("unsupported constraints: %v", err)
	} else if err != nil {
		return err
	}

	defer cleanup()
	if err := bootstrapFuncs.EnsureNotBootstrapped(environ); err != nil {
		return err
	}

	// Block interruption during bootstrap. Providers may also
	// register for interrupt notification so they can exit early.
	interrupted := make(chan os.Signal, 1)
	defer close(interrupted)
	ctx.InterruptNotify(interrupted)
	defer ctx.StopInterruptNotify(interrupted)
	go func() {
		for _ = range interrupted {
			ctx.Infof("Interrupt signalled: waiting for bootstrap to exit")
		}
	}()

	// If --metadata-source is specified, override the default tools metadata source so
	// SyncTools can use it, and also upload any image metadata.
	if c.MetadataSource != "" {
		metadataDir := ctx.AbsPath(c.MetadataSource)
		logger.Infof("Setting default tools and image metadata sources: %s", metadataDir)
		tools.DefaultBaseURL = metadataDir
		if err := imagemetadata.UploadImageMetadata(environ.Storage(), metadataDir); err != nil {
			// Do not error if image metadata directory doesn't exist.
			if !os.IsNotExist(err) {
				return fmt.Errorf("uploading image metadata: %v", err)
			}
		} else {
			logger.Infof("custom image metadata uploaded")
		}
	}
	// TODO (wallyworld): 2013-09-20 bug 1227931
	// We can set a custom tools data source instead of doing an
	// unnecessary upload.
	if environ.Config().Type() == provider.Local {
		c.UploadTools = true
	}
	if c.UploadTools {
		err = bootstrapFuncs.UploadTools(ctx, environ, c.Constraints.Arch, true, c.Series...)
		if err != nil {
			return err
		}
	}
	return bootstrapFuncs.Bootstrap(ctx, environ, environs.BootstrapParams{
		Constraints: c.Constraints,
		Placement:   c.Placement,
	})
}

// Run connects to the specified environment and starts the charm
// upgrade process.
func (c *UpgradeCharmCommand) Run(ctx *cmd.Context) error {
	client, err := juju.NewAPIClientFromName(c.EnvName)
	if err != nil {
		return err
	}
	defer client.Close()
	oldURL, err := client.ServiceGetCharmURL(c.ServiceName)
	if err != nil {
		return err
	}

	attrs, err := client.EnvironmentGet()
	if err != nil {
		return err
	}
	conf, err := config.New(config.NoDefaults, attrs)
	if err != nil {
		return err
	}

	var newURL *charm.URL
	if c.SwitchURL != "" {
		newURL, err = resolveCharmURL(c.SwitchURL, client, conf)
		if err != nil {
			return err
		}
	} else {
		// No new URL specified, but revision might have been.
		newURL = oldURL.WithRevision(c.Revision)
	}

	repo, err := charm.InferRepository(newURL.Reference, ctx.AbsPath(c.RepoPath))
	if err != nil {
		return err
	}
	repo = config.SpecializeCharmRepo(repo, conf)

	// If no explicit revision was set with either SwitchURL
	// or Revision flags, discover the latest.
	explicitRevision := true
	if newURL.Revision == -1 {
		explicitRevision = false
		latest, err := charm.Latest(repo, newURL)
		if err != nil {
			return err
		}
		newURL = newURL.WithRevision(latest)
	}
	if *newURL == *oldURL {
		if explicitRevision {
			return fmt.Errorf("already running specified charm %q", newURL)
		} else if newURL.Schema == "cs" {
			// No point in trying to upgrade a charm store charm when
			// we just determined that's the latest revision
			// available.
			return fmt.Errorf("already running latest charm %q", newURL)
		}
	}

	addedURL, err := addCharmViaAPI(client, ctx, newURL, repo)
	if err != nil {
		return err
	}

	return client.ServiceSetCharm(c.ServiceName, addedURL.String(), c.Force)
}

func (c *ConfigCommand) ReadConfig(ctx *cmd.Context) (err error) {
	c.Config, err = store.ReadConfig(ctx.AbsPath(c.ConfigPath))
	return err
}

func (c *AddMachineCommand) Run(ctx *cmd.Context) error {
	if c.Placement != nil && c.Placement.Scope == "ssh" {
		args := manual.ProvisionMachineArgs{
			Host:    c.Placement.Directive,
			EnvName: c.EnvName,
			Stdin:   ctx.Stdin,
			Stdout:  ctx.Stdout,
			Stderr:  ctx.Stderr,
		}
		_, err := manual.ProvisionMachine(args)
		return err
	}

	client, err := juju.NewAPIClientFromName(c.EnvName)
	if err != nil {
		return err
	}
	defer client.Close()

	if c.Placement != nil && c.Placement.Scope == instance.MachineScope {
		// It does not make sense to add-machine <id>.
		return fmt.Errorf("machine-id cannot be specified when adding machines")
	}

	machineParams := params.AddMachineParams{
		Placement:   c.Placement,
		Series:      c.Series,
		Constraints: c.Constraints,
		Jobs:        []params.MachineJob{params.JobHostUnits},
	}
	results, err := client.AddMachines([]params.AddMachineParams{machineParams})
	if params.IsCodeNotImplemented(err) {
		if c.Placement != nil {
			containerType, parseErr := instance.ParseContainerType(c.Placement.Scope)
			if parseErr != nil {
				// The user specified a non-container placement directive:
				// return original API not implemented error.
				return err
			}
			machineParams.ContainerType = containerType
			machineParams.ParentId = c.Placement.Directive
			machineParams.Placement = nil
		}
		logger.Infof(
			"AddMachinesWithPlacement not supported by the API server, " +
				"falling back to 1.18 compatibility mode",
		)
		results, err = client.AddMachines1dot18([]params.AddMachineParams{machineParams})
	}
	if err != nil {
		return err
	}

	// Currently, only one machine is added, but in future there may be several added in one call.
	machineInfo := results[0]
	if machineInfo.Error != nil {
		return machineInfo.Error
	}
	machineId := machineInfo.Machine

	if names.IsContainerMachine(machineId) {
		ctx.Infof("created container %v", machineId)
	} else {
		ctx.Infof("created machine %v", machineId)
	}
	return nil
}

func (c *PublishCommand) Run(ctx *cmd.Context) (err error) {
	branch := bzr.New(ctx.AbsPath(c.CharmPath))
	if _, err := os.Stat(branch.Join(".bzr")); err != nil {
		return fmt.Errorf("not a charm branch: %s", branch.Location())
	}
	if err := branch.CheckClean(); err != nil {
		return err
	}

	var curl *charm.URL
	if c.URL == "" {
		if err == nil {
			loc, err := branch.PushLocation()
			if err != nil {
				return fmt.Errorf("no charm URL provided and cannot infer from current directory (no push location)")
			}
			curl, err = charm.Store.CharmURL(loc)
			if err != nil {
				return fmt.Errorf("cannot infer charm URL from branch location: %q", loc)
			}
		}
	} else {
		curl, err = charm.InferURL(c.URL, "")
		if err != nil {
			return err
		}
	}

	pushLocation := charm.Store.BranchLocation(curl)
	if c.changePushLocation != nil {
		pushLocation = c.changePushLocation(pushLocation)
	}

	repo, err := charm.InferRepository(curl.Reference, "/not/important")
	if err != nil {
		return err
	}
	if repo != charm.Store {
		return fmt.Errorf("charm URL must reference the juju charm store")
	}

	localDigest, err := branch.RevisionId()
	if err != nil {
		return fmt.Errorf("cannot obtain local digest: %v", err)
	}
	logger.Infof("local digest is %s", localDigest)

	ch, err := charm.ReadDir(branch.Location())
	if err != nil {
		return err
	}
	if ch.Meta().Name != curl.Name {
		return fmt.Errorf("charm name in metadata must match name in URL: %q != %q", ch.Meta().Name, curl.Name)
	}

	oldEvent, err := charm.Store.Event(curl, localDigest)
	if _, ok := err.(*charm.NotFoundError); ok {
		oldEvent, err = charm.Store.Event(curl, "")
		if _, ok := err.(*charm.NotFoundError); ok {
			logger.Infof("charm %s is not yet in the store", curl)
			err = nil
		}
	}
	if err != nil {
		return fmt.Errorf("cannot obtain event details from the store: %s", err)
	}

	if oldEvent != nil && oldEvent.Digest == localDigest {
		return handleEvent(ctx, curl, oldEvent)
	}

	logger.Infof("sending charm to the charm store...")

	err = branch.Push(&bzr.PushAttr{Location: pushLocation, Remember: true})
	if err != nil {
		return err
	}
	logger.Infof("charm sent; waiting for it to be published...")
	for {
		time.Sleep(c.pollDelay)
		newEvent, err := charm.Store.Event(curl, "")
		if _, ok := err.(*charm.NotFoundError); ok {
			continue
		}
		if err != nil {
			return fmt.Errorf("cannot obtain event details from the store: %s", err)
		}
		if oldEvent != nil && oldEvent.Digest == newEvent.Digest {
			continue
		}
		if newEvent.Digest != localDigest {
			// TODO Check if the published digest is in the local history.
			return fmt.Errorf("charm changed but not to local charm digest; publishing race?")
		}
		return handleEvent(ctx, curl, newEvent)
	}
}