func (s *SimpleStreamsToolsSuite) TestFindTools(c *gc.C) {
	for i, test := range findToolsTests {
		c.Logf("\ntest %d: %s", i, test.info)
		s.reset(c, nil)
		custom := s.uploadCustom(c, test.custom...)
		public := s.uploadPublic(c, test.public...)
		stream := envtools.PreferredStream(&version.Current, s.env.Config().Development(), s.env.Config().AgentStream())
		actual, err := envtools.FindTools(s.env, test.major, test.minor, stream, coretools.Filter{})
		if test.err != nil {
			if len(actual) > 0 {
				c.Logf(actual.String())
			}
			c.Check(err, jc.Satisfies, errors.IsNotFound)
			continue
		}
		expect := map[version.Binary]string{}
		for _, expected := range test.expect {
			// If the tools exist in custom, that's preferred.
			var ok bool
			if expect[expected], ok = custom[expected]; !ok {
				expect[expected] = public[expected]
			}
		}
		c.Check(actual.URLs(), gc.DeepEquals, expect)
	}
}

func checkToolsAvailability(cfg *config.Config, finder toolsFinder) (version.Number, error) {
	currentVersion, ok := cfg.AgentVersion()
	if !ok || currentVersion == version.Zero {
		return version.Zero, nil
	}

	env, err := newEnvirons(cfg)
	if err != nil {
		return version.Zero, errors.Annotatef(err, "cannot make environ")
	}

	// finder receives major and minor as parameters as it uses them to filter versions and
	// only return patches for the passed major.minor (from major.minor.patch).
	// We'll try the released stream first, then fall back to the current configured stream
	// if no released tools are found.
	vers, err := finder(env, currentVersion.Major, currentVersion.Minor, tools.ReleasedStream, coretools.Filter{})
	preferredStream := tools.PreferredStream(&currentVersion, cfg.Development(), cfg.AgentStream())
	if preferredStream != tools.ReleasedStream && errors.Cause(err) == coretools.ErrNoMatches {
		vers, err = finder(env, currentVersion.Major, currentVersion.Minor, preferredStream, coretools.Filter{})
	}
	if err != nil {
		return version.Zero, errors.Annotatef(err, "cannot find available tools")
	}
	// Newest also returns a list of the items in this list matching with the
	// newest version.
	newest, _ := vers.Newest()
	return newest, nil
}

// StartInstanceWithParams is a test helper function that starts an instance
// with the given parameters, and a plausible but invalid configuration, and
// returns the result of Environ.StartInstance. The provided params's
// InstanceConfig and Tools field values will be ignored.
func StartInstanceWithParams(
	env environs.Environ, machineId string,
	params environs.StartInstanceParams,
	networks []string,
) (
	*environs.StartInstanceResult, error,
) {
	preferredSeries := config.PreferredSeries(env.Config())
	agentVersion, ok := env.Config().AgentVersion()
	if !ok {
		return nil, errors.New("missing agent version in model config")
	}
	filter := coretools.Filter{
		Number: agentVersion,
		Series: preferredSeries,
	}
	if params.Constraints.Arch != nil {
		filter.Arch = *params.Constraints.Arch
	}
	stream := tools.PreferredStream(&agentVersion, env.Config().Development(), env.Config().AgentStream())
	possibleTools, err := tools.FindTools(env, -1, -1, stream, filter)
	if err != nil {
		return nil, errors.Trace(err)
	}

	if params.ImageMetadata == nil {
		if err := SetImageMetadata(
			env,
			possibleTools.AllSeries(),
			possibleTools.Arches(),
			&params.ImageMetadata,
		); err != nil {
			return nil, errors.Trace(err)
		}
	}

	machineNonce := "fake_nonce"
	stateInfo := FakeStateInfo(machineId)
	apiInfo := FakeAPIInfo(machineId)
	instanceConfig, err := instancecfg.NewInstanceConfig(
		machineId,
		machineNonce,
		imagemetadata.ReleasedStream,
		preferredSeries,
		"",
		true,
		networks,
		stateInfo,
		apiInfo,
	)
	if err != nil {
		return nil, errors.Trace(err)
	}
	eUUID, _ := env.Config().UUID()
	instanceConfig.Tags[tags.JujuModel] = eUUID
	params.Tools = possibleTools
	params.InstanceConfig = instanceConfig
	return env.StartInstance(params)
}

// findAvailableTools returns a list of available tools,
// including tools that may be locally built and then
// uploaded. Tools that need to be built will have an
// empty URL.
func findAvailableTools(env environs.Environ, vers *version.Number, arch *string, upload bool) (coretools.List, error) {
	if upload {
		// We're forcing an upload: ensure we can do so.
		if err := validateUploadAllowed(env, arch); err != nil {
			return nil, err
		}
		return locallyBuildableTools(), nil
	}

	// We're not forcing an upload, so look for tools
	// in the environment's simplestreams search paths
	// for existing tools.

	// If the user hasn't asked for a specified tools version, see if
	// one is configured in the environment.
	if vers == nil {
		if agentVersion, ok := env.Config().AgentVersion(); ok {
			vers = &agentVersion
		}
	}
	logger.Infof("looking for bootstrap tools: version=%v", vers)
	toolsList, findToolsErr := findBootstrapTools(env, vers, arch)
	if findToolsErr != nil && !errors.IsNotFound(findToolsErr) {
		return nil, findToolsErr
	}

	preferredStream := envtools.PreferredStream(vers, env.Config().Development(), env.Config().AgentStream())
	if preferredStream == envtools.ReleasedStream || vers != nil {
		// We are not running a development build, or agent-version
		// was specified; the only tools available are the ones we've
		// just found.
		return toolsList, findToolsErr
	}
	// The tools located may not include the ones that the
	// provider requires. We are running a development build,
	// so augment the list of tools with those that we can build
	// locally.

	// Collate the set of arch+series that are externally available
	// so we can see if we need to build any locally. If we need
	// to, only then do we validate that we can upload (which
	// involves a potentially expensive SupportedArchitectures call).
	archSeries := make(set.Strings)
	for _, tools := range toolsList {
		archSeries.Add(tools.Version.Arch + tools.Version.Series)
	}
	var localToolsList coretools.List
	for _, tools := range locallyBuildableTools() {
		if !archSeries.Contains(tools.Version.Arch + tools.Version.Series) {
			localToolsList = append(localToolsList, tools)
		}
	}
	if len(localToolsList) == 0 || validateUploadAllowed(env, arch) != nil {
		return toolsList, findToolsErr
	}
	return append(toolsList, localToolsList...), nil
}

// findBootstrapTools returns a tools.List containing only those tools with
// which it would be reasonable to launch an environment's first machine,
// given the supplied constraints. If a specific agent version is not requested,
// all tools matching the current major.minor version are chosen.
func findBootstrapTools(env environs.Environ, vers *version.Number, arch *string) (list coretools.List, err error) {
	// Construct a tools filter.
	cliVersion := version.Current.Number
	var filter coretools.Filter
	if arch != nil {
		filter.Arch = *arch
	}
	if vers != nil {
		filter.Number = *vers
	}
	stream := envtools.PreferredStream(vers, env.Config().Development(), env.Config().AgentStream())
	return findTools(env, cliVersion.Major, cliVersion.Minor, stream, filter)
}

func (s *SimpleStreamsToolsSuite) TestPreferredStream(c *gc.C) {
	for i, test := range preferredStreamTests {
		c.Logf("\ntest %d", i)
		s.PatchValue(&version.Current, version.MustParse(test.currentVers))
		var vers *version.Number
		if test.explicitVers != "" {
			v := version.MustParse(test.explicitVers)
			vers = &v
		}
		obtained := envtools.PreferredStream(vers, test.forceDevel, test.streamInConfig)
		c.Check(obtained, gc.Equals, test.expected)
	}
}

// findMatchingTools searches toolstorage and simplestreams for tools matching the
// given parameters. If an exact match is specified (number, series and arch)
// and is found in toolstorage, then simplestreams will not be searched.
func (f *ToolsFinder) findMatchingTools(args params.FindToolsParams) (coretools.List, error) {
	exactMatch := args.Number != version.Zero && args.Series != "" && args.Arch != ""
	storageList, err := f.matchingStorageTools(args)
	if err == nil && exactMatch {
		return storageList, nil
	} else if err != nil && err != coretools.ErrNoMatches {
		return nil, err
	}

	// Look for tools in simplestreams too, but don't replace
	// any versions found in storage.
	cfg, err := f.configGetter.ModelConfig()
	if err != nil {
		return nil, err
	}
	env, err := environs.New(cfg)
	if err != nil {
		return nil, err
	}
	filter := toolsFilter(args)
	stream := envtools.PreferredStream(&args.Number, cfg.Development(), cfg.AgentStream())
	simplestreamsList, err := envtoolsFindTools(
		env, args.MajorVersion, args.MinorVersion, stream, filter,
	)
	if len(storageList) == 0 && err != nil {
		return nil, err
	}

	list := storageList
	found := make(map[version.Binary]bool)
	for _, tools := range storageList {
		found[tools.Version] = true
	}
	for _, tools := range simplestreamsList {
		if !found[tools.Version] {
			list = append(list, tools)
		}
	}
	sort.Sort(list)
	return list, nil
}

// Run initializes state for an environment.
func (c *BootstrapCommand) Run(_ *cmd.Context) error {
	envCfg, err := config.New(config.NoDefaults, c.ControllerModelConfig)
	if err != nil {
		return err
	}
	err = c.ReadConfig("machine-0")
	if err != nil {
		return err
	}
	agentConfig := c.CurrentConfig()
	network.SetPreferIPv6(agentConfig.PreferIPv6())

	// agent.Jobs is an optional field in the agent config, and was
	// introduced after 1.17.2. We default to allowing units on
	// machine-0 if missing.
	jobs := agentConfig.Jobs()
	if len(jobs) == 0 {
		jobs = []multiwatcher.MachineJob{
			multiwatcher.JobManageModel,
			multiwatcher.JobHostUnits,
			multiwatcher.JobManageNetworking,
		}
	}

	// Get the bootstrap machine's addresses from the provider.
	env, err := environs.New(envCfg)
	if err != nil {
		return err
	}
	newConfigAttrs := make(map[string]interface{})

	// Check to see if a newer agent version has been requested
	// by the bootstrap client.
	desiredVersion, ok := envCfg.AgentVersion()
	if ok && desiredVersion != jujuversion.Current {
		// If we have been asked for a newer version, ensure the newer
		// tools can actually be found, or else bootstrap won't complete.
		stream := envtools.PreferredStream(&desiredVersion, envCfg.Development(), envCfg.AgentStream())
		logger.Infof("newer tools requested, looking for %v in stream %v", desiredVersion, stream)
		filter := tools.Filter{
			Number: desiredVersion,
			Arch:   arch.HostArch(),
			Series: series.HostSeries(),
		}
		_, toolsErr := envtools.FindTools(env, -1, -1, stream, filter)
		if toolsErr == nil {
			logger.Infof("tools are available, upgrade will occur after bootstrap")
		}
		if errors.IsNotFound(toolsErr) {
			// Newer tools not available, so revert to using the tools
			// matching the current agent version.
			logger.Warningf("newer tools for %q not available, sticking with version %q", desiredVersion, jujuversion.Current)
			newConfigAttrs["agent-version"] = jujuversion.Current.String()
		} else if toolsErr != nil {
			logger.Errorf("cannot find newer tools: %v", toolsErr)
			return toolsErr
		}
	}

	instanceId := instance.Id(c.InstanceId)
	instances, err := env.Instances([]instance.Id{instanceId})
	if err != nil {
		return err
	}
	addrs, err := instances[0].Addresses()
	if err != nil {
		return err
	}

	// When machine addresses are reported from state, they have
	// duplicates removed.  We should do the same here so that
	// there is not unnecessary churn in the mongo replicaset.
	// TODO (cherylj) Add explicit unit tests for this - tracked
	// by bug #1544158.
	addrs = network.MergedAddresses([]network.Address{}, addrs)

	// Generate a private SSH key for the controllers, and add
	// the public key to the environment config. We'll add the
	// private key to StateServingInfo below.
	privateKey, publicKey, err := sshGenerateKey(config.JujuSystemKey)
	if err != nil {
		return errors.Annotate(err, "failed to generate system key")
	}
	authorizedKeys := config.ConcatAuthKeys(envCfg.AuthorizedKeys(), publicKey)
	newConfigAttrs[config.AuthKeysConfig] = authorizedKeys

	// Generate a shared secret for the Mongo replica set, and write it out.
	sharedSecret, err := mongo.GenerateSharedSecret()
	if err != nil {
		return err
	}
	info, ok := agentConfig.StateServingInfo()
	if !ok {
		return fmt.Errorf("bootstrap machine config has no state serving info")
	}
	info.SharedSecret = sharedSecret
	info.SystemIdentity = privateKey
	err = c.ChangeConfig(func(agentConfig agent.ConfigSetter) error {
		agentConfig.SetStateServingInfo(info)
//.........这里部分代码省略.........

// SyncTools copies the Juju tools tarball from the official bucket
// or a specified source directory into the user's environment.
func SyncTools(syncContext *SyncContext) error {
	sourceDataSource, err := selectSourceDatasource(syncContext)
	if err != nil {
		return err
	}

	logger.Infof("listing available tools")
	if syncContext.MajorVersion == 0 && syncContext.MinorVersion == 0 {
		syncContext.MajorVersion = jujuversion.Current.Major
		syncContext.MinorVersion = -1
		if !syncContext.AllVersions {
			syncContext.MinorVersion = jujuversion.Current.Minor
		}
	}

	toolsDir := syncContext.Stream
	// If no stream has been specified, assume "released" for non-devel versions of Juju.
	if syncContext.Stream == "" {
		// We now store the tools in a directory named after their stream, but the
		// legacy behaviour is to store all tools in a single "releases" directory.
		toolsDir = envtools.LegacyReleaseDirectory
		syncContext.Stream = envtools.PreferredStream(&jujuversion.Current, false, syncContext.Stream)
	}
	sourceTools, err := envtools.FindToolsForCloud(
		[]simplestreams.DataSource{sourceDataSource}, simplestreams.CloudSpec{},
		syncContext.Stream, syncContext.MajorVersion, syncContext.MinorVersion, coretools.Filter{})
	// For backwards compatibility with cloud storage, if there are no tools in the specified stream,
	// double check the release stream.
	// TODO - remove this when we no longer need to support cloud storage upgrades.
	if err == envtools.ErrNoTools {
		sourceTools, err = envtools.FindToolsForCloud(
			[]simplestreams.DataSource{sourceDataSource}, simplestreams.CloudSpec{},
			envtools.ReleasedStream, syncContext.MajorVersion, syncContext.MinorVersion, coretools.Filter{})
	}
	if err != nil {
		return err
	}

	logger.Infof("found %d tools", len(sourceTools))
	if !syncContext.AllVersions {
		var latest version.Number
		latest, sourceTools = sourceTools.Newest()
		logger.Infof("found %d recent tools (version %s)", len(sourceTools), latest)
	}
	for _, tool := range sourceTools {
		logger.Debugf("found source tool: %v", tool)
	}

	logger.Infof("listing target tools storage")
	targetTools, err := syncContext.TargetToolsFinder.FindTools(syncContext.MajorVersion, syncContext.Stream)
	switch err {
	case nil, coretools.ErrNoMatches, envtools.ErrNoTools:
	default:
		return err
	}
	for _, tool := range targetTools {
		logger.Debugf("found target tool: %v", tool)
	}

	missing := sourceTools.Exclude(targetTools)
	logger.Infof("found %d tools in target; %d tools to be copied", len(targetTools), len(missing))
	if syncContext.DryRun {
		for _, tools := range missing {
			logger.Infof("copying %s from %s", tools.Version, tools.URL)
		}
		return nil
	}

	err = copyTools(toolsDir, syncContext.Stream, missing, syncContext.TargetToolsUploader)
	if err != nil {
		return err
	}
	logger.Infof("copied %d tools", len(missing))
	return nil
}

func fillinStartInstanceParams(env environs.Environ, machineId string, isController bool, params *environs.StartInstanceParams) error {
	if params.ControllerUUID == "" {
		return errors.New("missing controller UUID in start instance parameters")
	}
	preferredSeries := config.PreferredSeries(env.Config())
	agentVersion, ok := env.Config().AgentVersion()
	if !ok {
		return errors.New("missing agent version in model config")
	}
	filter := coretools.Filter{
		Number: agentVersion,
		Series: preferredSeries,
	}
	if params.Constraints.Arch != nil {
		filter.Arch = *params.Constraints.Arch
	}
	stream := tools.PreferredStream(&agentVersion, env.Config().Development(), env.Config().AgentStream())
	possibleTools, err := tools.FindTools(env, -1, -1, stream, filter)
	if err != nil {
		return errors.Trace(err)
	}

	if params.ImageMetadata == nil {
		if err := SetImageMetadata(
			env,
			possibleTools.AllSeries(),
			possibleTools.Arches(),
			&params.ImageMetadata,
		); err != nil {
			return errors.Trace(err)
		}
	}

	machineNonce := "fake_nonce"
	apiInfo := FakeAPIInfo(machineId)
	instanceConfig, err := instancecfg.NewInstanceConfig(
		testing.ControllerTag,
		machineId,
		machineNonce,
		imagemetadata.ReleasedStream,
		preferredSeries,
		apiInfo,
	)
	if err != nil {
		return errors.Trace(err)
	}
	if isController {
		instanceConfig.Controller = &instancecfg.ControllerConfig{
			Config: testing.FakeControllerConfig(),
			MongoInfo: &mongo.MongoInfo{
				Info: mongo.Info{
					Addrs:  []string{"127.0.0.1:1234"},
					CACert: "CA CERT\n" + testing.CACert,
				},
				Password: "mongosecret",
				Tag:      names.NewMachineTag(machineId),
			},
		}
		instanceConfig.Jobs = []multiwatcher.MachineJob{multiwatcher.JobHostUnits, multiwatcher.JobManageModel}
	}
	cfg := env.Config()
	instanceConfig.Tags = instancecfg.InstanceTags(env.Config().UUID(), params.ControllerUUID, cfg, nil)
	params.Tools = possibleTools
	params.InstanceConfig = instanceConfig
	return nil
}