Golang cmd.Context类代码示例

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)
}

// Run connects to the specified environment and starts the charm
// upgrade process.
func (c *UpgradeCharmCommand) Run(ctx *cmd.Context) error {
	conn, err := juju.NewConnFromName(c.EnvName)
	if err != nil {
		return err
	}
	defer conn.Close()
	service, err := conn.State.Service(c.ServiceName)
	if err != nil {
		return err
	}
	oldURL, _ := service.CharmURL()
	var newURL *charm.URL
	if c.SwitchURL != "" {
		// A new charm URL was explicitly specified.
		conf, err := conn.State.EnvironConfig()
		if err != nil {
			return err
		}
		newURL, err = charm.InferURL(c.SwitchURL, conf.DefaultSeries())
		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, ctx.AbsPath(c.RepoPath))
	if err != nil {
		return err
	}
	// 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 := repo.Latest(newURL)
		if err != nil {
			return err
		}
		newURL = newURL.WithRevision(latest)
	}
	bumpRevision := false
	if *newURL == *oldURL {
		if explicitRevision {
			return fmt.Errorf("already running specified charm %q", newURL)
		}
		// Only try bumping the revision when necessary (local dir charm).
		if _, isLocal := repo.(*charm.LocalRepository); !isLocal {
			// TODO(dimitern): If the --force flag is set to something
			// different to before, we might actually want to allow this
			// case (and the other error below). LP bug #1174287
			return fmt.Errorf("already running latest charm %q", newURL)
		}
		// This is a local repository.
		if ch, err := repo.Get(newURL); err != nil {
			return err
		} else if _, bumpRevision = ch.(*charm.Dir); !bumpRevision {
			// Only bump the revision when it's a directory.
			return fmt.Errorf("cannot increment revision of charm %q: not a directory", newURL)
		}
	}
	sch, err := conn.PutCharm(newURL, repo, bumpRevision)
	if err != nil {
		return err
	}
	return service.SetCharm(sch, c.Force)
}

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, "/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)
	}
	log.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 {
			log.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)
	}

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

	err = branch.Push(&bzr.PushAttr{Location: pushLocation, Remember: true})
	if err != nil {
		return err
	}
	log.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)
	}
	return nil
}

func (c *DeployCommand) Run(ctx *cmd.Context) error {
	conn, err := juju.NewConnFromName(c.EnvName)
	if err != nil {
		return err
	}
	defer conn.Close()
	conf, err := conn.State.EnvironConfig()
	if err != nil {
		return err
	}
	curl, err := charm.InferURL(c.CharmName, conf.DefaultSeries())
	if err != nil {
		return err
	}
	repo, err := charm.InferRepository(curl, ctx.AbsPath(c.RepoPath))
	if err != nil {
		return err
	}
	// TODO(fwereade) it's annoying to roundtrip the bytes through the client
	// here, but it's the original behaviour and not convenient to change.
	// PutCharm will always be required in some form for local charms; and we
	// will need an EnsureStoreCharm method somewhere that gets the state.Charm
	// for use in the following checks.
	ch, err := conn.PutCharm(curl, repo, c.BumpRevision)
	if err != nil {
		return err
	}
	numUnits := c.NumUnits
	if ch.Meta().Subordinate {
		empty := constraints.Value{}
		if c.Constraints != empty {
			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 = ch.Meta().Name
	}
	var settings charm.Settings
	if c.Config.Path != "" {
		configYAML, err := c.Config.Read(ctx)
		if err != nil {
			return err
		}
		settings, err = ch.Config().ParseSettingsYAML(configYAML, serviceName)
		if err != nil {
			return err
		}
	}
	_, err = conn.DeployService(juju.DeployServiceParams{
		ServiceName:    serviceName,
		Charm:          ch,
		NumUnits:       numUnits,
		ConfigSettings: settings,
		Constraints:    c.Constraints,
		ToMachineSpec:  c.ToMachineSpec,
	})
	return err
}