func (*cloudinitSuite) TestWindowsCloudInit(c *gc.C) {
	for i, test := range windowsCloudinitTests {
		c.Logf("test %d", i)
		dataDir, err := paths.DataDir(test.cfg.Series)
		c.Assert(err, gc.IsNil)
		logDir, err := paths.LogDir(test.cfg.Series)
		c.Assert(err, gc.IsNil)

		test.cfg.DataDir = dataDir
		test.cfg.LogDir = path.Join(logDir, "juju")

		ci := coreCloudinit.New()
		udata, err := cloudinit.NewUserdataConfig(&test.cfg, ci)

		c.Assert(err, gc.IsNil)
		err = udata.Configure()

		c.Assert(err, gc.IsNil)
		c.Check(ci, gc.NotNil)
		data, err := udata.Render()
		c.Assert(err, gc.IsNil)

		stringData := strings.Replace(string(data), "\r\n", "\n", -1)
		stringData = strings.Replace(stringData, "\t", " ", -1)
		stringData = strings.TrimSpace(stringData)

		compareString := strings.Replace(string(test.expectScripts), "\r\n", "\n", -1)
		compareString = strings.Replace(compareString, "\t", " ", -1)
		compareString = strings.TrimSpace(compareString)

		c.Assert(stringData, gc.Equals, compareString)

	}
}

func (s *format_1_16Suite) TestMissingAttributes(c *gc.C) {
	logDir, err := paths.LogDir(series.HostSeries())
	c.Assert(err, jc.ErrorIsNil)
	realDataDir, err := paths.DataDir(series.HostSeries())
	c.Assert(err, jc.ErrorIsNil)

	realDataDir = filepath.FromSlash(realDataDir)
	logPath := filepath.Join(logDir, "juju")
	logPath = filepath.FromSlash(logPath)

	dataDir := c.MkDir()
	formatPath := filepath.Join(dataDir, legacyFormatFilename)
	err = utils.AtomicWriteFile(formatPath, []byte(legacyFormatFileContents), 0600)
	c.Assert(err, jc.ErrorIsNil)
	configPath := filepath.Join(dataDir, agentConfigFilename)

	err = utils.AtomicWriteFile(configPath, []byte(configDataWithoutNewAttributes), 0600)
	c.Assert(err, jc.ErrorIsNil)
	readConfig, err := ReadConfig(configPath)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(readConfig.UpgradedToVersion(), gc.Equals, version.MustParse("1.16.0"))
	configLogDir := filepath.FromSlash(readConfig.LogDir())
	configDataDir := filepath.FromSlash(readConfig.DataDir())

	c.Assert(configLogDir, gc.Equals, logPath)
	c.Assert(configDataDir, gc.Equals, realDataDir)
	// Test data doesn't include a StateServerKey so StateServingInfo
	// should *not* be available
	_, available := readConfig.StateServingInfo()
	c.Assert(available, jc.IsFalse)
}

func (s *format_1_18Suite) TestMissingAttributes(c *gc.C) {
	logDir, err := paths.LogDir(series.HostSeries())
	c.Assert(err, jc.ErrorIsNil)
	realDataDir, err := paths.DataDir(series.HostSeries())
	c.Assert(err, jc.ErrorIsNil)

	realDataDir = filepath.FromSlash(realDataDir)
	logPath := filepath.Join(logDir, "juju")
	logPath = filepath.FromSlash(logPath)

	dataDir := c.MkDir()
	configPath := filepath.Join(dataDir, agentConfigFilename)
	err = utils.AtomicWriteFile(configPath, []byte(configData1_18WithoutUpgradedToVersion), 0600)
	c.Assert(err, jc.ErrorIsNil)
	readConfig, err := ReadConfig(configPath)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(readConfig.UpgradedToVersion(), gc.Equals, version.MustParse("1.16.0"))
	configLogDir := filepath.FromSlash(readConfig.LogDir())
	configDataDir := filepath.FromSlash(readConfig.DataDir())
	c.Assert(configLogDir, gc.Equals, logPath)
	c.Assert(configDataDir, gc.Equals, realDataDir)
	c.Assert(readConfig.PreferIPv6(), jc.IsFalse)
	// The api info doesn't have the environment tag set.
	apiInfo, ok := readConfig.APIInfo()
	c.Assert(ok, jc.IsTrue)
	c.Assert(apiInfo.EnvironTag.Id(), gc.Equals, "")
}

func (s *initSystemSuite) SetUpTest(c *gc.C) {
	s.BaseSuite.SetUpTest(c)

	dataDir, err := paths.DataDir("vivid")
	c.Assert(err, jc.ErrorIsNil)
	s.dataDir = dataDir
	// Patch things out.
	s.ch = systemd.PatchNewChan(s)

	s.stub = &testing.Stub{}
	s.conn = systemd.PatchNewConn(s, s.stub)
	s.fops = systemd.PatchFileOps(s, s.stub)
	s.exec = systemd.PatchExec(s, s.stub)

	// Set up the service.
	tagStr := "machine-0"
	tag, err := names.ParseTag(tagStr)
	c.Assert(err, jc.ErrorIsNil)
	s.tag = tag
	s.name = "jujud-" + tagStr
	s.conf = common.Conf{
		Desc:      "juju agent for " + tagStr,
		ExecStart: jujud + " " + tagStr,
	}
	s.service = s.newService(c)

	// Reset any incidental calls.
	s.stub.ResetCalls()
}

func newService(name string, conf common.Conf, initSystem, series string) (Service, error) {
	switch initSystem {
	case InitSystemWindows:
		svc, err := windows.NewService(name, conf)
		if err != nil {
			return nil, errors.Annotatef(err, "failed to wrap service %q", name)
		}
		return svc, nil
	case InitSystemUpstart:
		return upstart.NewService(name, conf), nil
	case InitSystemSystemd:
		dataDir, err := paths.DataDir(series)
		if err != nil {
			return nil, errors.Annotatef(err, "failed to find juju data dir for service %q", name)
		}

		svc, err := systemd.NewService(name, conf, dataDir)
		if err != nil {
			return nil, errors.Annotatef(err, "failed to wrap service %q", name)
		}
		return svc, nil
	default:
		return nil, errors.NotFoundf("init system %q", initSystem)
	}
}

func (s *CloudInitSuite) TestWindowsUserdataEncoding(c *gc.C) {
	series := "win8"
	metricsSpoolDir := must(paths.MetricsSpoolDir("win8"))
	toolsList := tools.List{
		&tools.Tools{
			URL:     "http://foo.com/tools/released/juju1.2.3-win8-amd64.tgz",
			Version: version.MustParseBinary("1.2.3-win8-amd64"),
			Size:    10,
			SHA256:  "1234",
		},
	}
	dataDir, err := paths.DataDir(series)
	c.Assert(err, jc.ErrorIsNil)
	logDir, err := paths.LogDir(series)
	c.Assert(err, jc.ErrorIsNil)

	cfg := instancecfg.InstanceConfig{
		ControllerTag:    testing.ControllerTag,
		MachineId:        "10",
		AgentEnvironment: map[string]string{agent.ProviderType: "dummy"},
		Series:           series,
		Jobs:             []multiwatcher.MachineJob{multiwatcher.JobHostUnits},
		MachineNonce:     "FAKE_NONCE",
		APIInfo: &api.Info{
			Addrs:    []string{"state-addr.testing.invalid:54321"},
			Password: "bletch",
			CACert:   "CA CERT\n" + testing.CACert,
			Tag:      names.NewMachineTag("10"),
			ModelTag: testing.ModelTag,
		},
		MachineAgentServiceName: "jujud-machine-10",
		DataDir:                 dataDir,
		LogDir:                  path.Join(logDir, "juju"),
		MetricsSpoolDir:         metricsSpoolDir,
		CloudInitOutputLog:      path.Join(logDir, "cloud-init-output.log"),
	}
	err = cfg.SetTools(toolsList)
	c.Assert(err, jc.ErrorIsNil)

	ci, err := cloudinit.New("win8")
	c.Assert(err, jc.ErrorIsNil)

	udata, err := cloudconfig.NewUserdataConfig(&cfg, ci)
	c.Assert(err, jc.ErrorIsNil)

	err = udata.Configure()
	c.Assert(err, jc.ErrorIsNil)

	data, err := ci.RenderYAML()
	c.Assert(err, jc.ErrorIsNil)

	cicompose, err := cloudinit.New("win8")
	c.Assert(err, jc.ErrorIsNil)

	base64Data := base64.StdEncoding.EncodeToString(utils.Gzip(data))
	got := []byte(fmt.Sprintf(cloudconfig.UserDataScript, base64Data))
	expected, err := providerinit.ComposeUserData(&cfg, cicompose, openstack.OpenstackRenderer{})
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(string(got), gc.Equals, string(expected))
}

// NewInstanceConfig sets up a basic machine configuration, for a
// non-bootstrap node. You'll still need to supply more information,
// but this takes care of the fixed entries and the ones that are
// always needed.
func NewInstanceConfig(
	machineID,
	machineNonce,
	imageStream,
	series,
	publicImageSigningKey string,
	secureServerConnections bool,
	networks []string,
	mongoInfo *mongo.MongoInfo,
	apiInfo *api.Info,
) (*InstanceConfig, error) {
	dataDir, err := paths.DataDir(series)
	if err != nil {
		return nil, err
	}
	logDir, err := paths.LogDir(series)
	if err != nil {
		return nil, err
	}
	metricsSpoolDir, err := paths.MetricsSpoolDir(series)
	if err != nil {
		return nil, err
	}
	cloudInitOutputLog := path.Join(logDir, "cloud-init-output.log")
	icfg := &InstanceConfig{
		// Fixed entries.
		DataDir:                 dataDir,
		LogDir:                  path.Join(logDir, "juju"),
		MetricsSpoolDir:         metricsSpoolDir,
		Jobs:                    []multiwatcher.MachineJob{multiwatcher.JobHostUnits},
		CloudInitOutputLog:      cloudInitOutputLog,
		MachineAgentServiceName: "jujud-" + names.NewMachineTag(machineID).String(),
		Series:                  series,
		Tags:                    map[string]string{},

		// Parameter entries.
		MachineId:             machineID,
		MachineNonce:          machineNonce,
		Networks:              networks,
		MongoInfo:             mongoInfo,
		APIInfo:               apiInfo,
		ImageStream:           imageStream,
		PublicImageSigningKey: publicImageSigningKey,
		AgentEnvironment: map[string]string{
			agent.AllowsSecureConnection: strconv.FormatBool(secureServerConnections),
		},
	}
	return icfg, nil
}

func (*utilSuite) TestMachineInfoCloudinitRunCmd(c *gc.C) {
	hostname := "hostname"
	info := machineInfo{hostname}
	filename := "/var/lib/juju/MAASmachine.txt"
	dataDir, err := paths.DataDir("quantal")
	c.Assert(err, jc.ErrorIsNil)
	cloudcfg, err := cloudinit.New("quantal")
	c.Assert(err, jc.ErrorIsNil)
	script, err := info.cloudinitRunCmd(cloudcfg)
	c.Assert(err, jc.ErrorIsNil)
	yaml, err := goyaml.Marshal(info)
	c.Assert(err, jc.ErrorIsNil)
	expected := fmt.Sprintf("mkdir -p '%s'\ncat > '%s' << 'EOF'\n'%s'\nEOF\nchmod 0755 '%s'", dataDir, filename, yaml, filename)
	c.Check(script, gc.Equals, expected)
}

// CheckAgentCommand is a utility function for verifying that common agent
// options are handled by a Command; it returns an instance of that
// command pre-parsed, with any mandatory flags added.
func CheckAgentCommand(c *gc.C, create acCreator, args []string) cmd.Command {
	com, conf := create()
	err := coretesting.InitCommand(com, args)
	dataDir, err := paths.DataDir(series.HostSeries())
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(conf.DataDir(), gc.Equals, dataDir)
	badArgs := append(args, "--data-dir", "")
	com, _ = create()
	err = coretesting.InitCommand(com, badArgs)
	c.Assert(err, gc.ErrorMatches, "--data-dir option must be set")

	args = append(args, "--data-dir", "jd")
	com, conf = create()
	c.Assert(coretesting.InitCommand(com, args), gc.IsNil)
	c.Assert(conf.DataDir(), gc.Equals, "jd")
	return com
}

// cloudinitRunCmd returns the shell command that, when run, will create the
// "machine info" file containing the hostname of a machine.
// That command is destined to be used by cloudinit.
func (info *machineInfo) cloudinitRunCmd(cloudcfg cloudinit.CloudConfig) (string, error) {
	dataDir, err := paths.DataDir(cloudcfg.GetSeries())
	if err != nil {
		return "", errors.Trace(err)
	}
	yaml, err := goyaml.Marshal(info)
	if err != nil {
		return "", errors.Trace(err)
	}
	renderer := cloudcfg.ShellRenderer()
	fileName := renderer.Join(renderer.FromSlash(dataDir), "MAASmachine.txt")
	script := renderer.MkdirAll(dataDir)
	contents := renderer.Quote(string(yaml))
	script = append(script, renderer.WriteFile(fileName, []byte(contents))...)
	script = append(script, renderer.Chmod(fileName, 0755)...)
	return strings.Join(script, "\n"), nil
}

// cloudinitRunCmd returns the shell command that, when run, will create the
// "machine info" file containing the hostname of a machine.
// That command is destined to be used by cloudinit.
func (info *machineInfo) cloudinitRunCmd(series string) (string, error) {
	dataDir, err := paths.DataDir(series)
	if err != nil {
		return "", err
	}
	renderer, err := cloudinit.NewRenderer(series)
	if err != nil {
		return "", err
	}

	yaml, err := goyaml.Marshal(info)
	if err != nil {
		return "", err
	}
	fileName := renderer.PathJoin(renderer.FromSlash(dataDir), "MAASmachine.txt")
	script := renderer.Mkdir(dataDir)
	contents := utils.ShQuote(string(yaml))
	script = append(script, renderer.WriteFile(fileName, contents, 0755)...)
	return strings.Join(script, "\n"), nil
}

// NewInstanceConfig sets up a basic machine configuration, for a
// non-bootstrap node. You'll still need to supply more information,
// but this takes care of the fixed entries and the ones that are
// always needed.
func NewInstanceConfig(
	controllerTag names.ControllerTag,
	machineID,
	machineNonce,
	imageStream,
	series string,
	apiInfo *api.Info,
) (*InstanceConfig, error) {
	dataDir, err := paths.DataDir(series)
	if err != nil {
		return nil, err
	}
	logDir, err := paths.LogDir(series)
	if err != nil {
		return nil, err
	}
	metricsSpoolDir, err := paths.MetricsSpoolDir(series)
	if err != nil {
		return nil, err
	}
	cloudInitOutputLog := path.Join(logDir, "cloud-init-output.log")
	icfg := &InstanceConfig{
		// Fixed entries.
		DataDir:                 dataDir,
		LogDir:                  path.Join(logDir, "juju"),
		MetricsSpoolDir:         metricsSpoolDir,
		Jobs:                    []multiwatcher.MachineJob{multiwatcher.JobHostUnits},
		CloudInitOutputLog:      cloudInitOutputLog,
		MachineAgentServiceName: "jujud-" + names.NewMachineTag(machineID).String(),
		Series:                  series,
		Tags:                    map[string]string{},

		// Parameter entries.
		ControllerTag: controllerTag,
		MachineId:     machineID,
		MachineNonce:  machineNonce,
		APIInfo:       apiInfo,
		ImageStream:   imageStream,
	}
	return icfg, nil
}

// NewMachineConfig sets up a basic machine configuration, for a
// non-bootstrap node. You'll still need to supply more information,
// but this takes care of the fixed entries and the ones that are
// always needed.
func NewMachineConfig(
	machineID,
	machineNonce,
	imageStream,
	series string,
	networks []string,
	mongoInfo *mongo.MongoInfo,
	apiInfo *api.Info,
) (*cloudinit.MachineConfig, error) {
	dataDir, err := paths.DataDir(series)
	if err != nil {
		return nil, err
	}
	logDir, err := paths.LogDir(series)
	if err != nil {
		return nil, err
	}
	cloudInitOutputLog := path.Join(logDir, "cloud-init-output.log")
	mcfg := &cloudinit.MachineConfig{
		// Fixed entries.
		DataDir:                 dataDir,
		LogDir:                  path.Join(logDir, "juju"),
		Jobs:                    []params.MachineJob{params.JobHostUnits},
		CloudInitOutputLog:      cloudInitOutputLog,
		MachineAgentServiceName: "jujud-" + names.NewMachineTag(machineID).String(),
		Series:                  series,

		// Parameter entries.
		MachineId:    machineID,
		MachineNonce: machineNonce,
		Networks:     networks,
		MongoInfo:    mongoInfo,
		APIInfo:      apiInfo,
		ImageStream:  imageStream,
	}
	return mcfg, nil
}

// Restore handles either returning or creating a controller to a backed up status:
// * extracts the content of the given backup file and:
// * runs mongorestore with the backed up mongo dump
// * updates and writes configuration files
// * updates existing db entries to make sure they hold no references to
// old instances
// * updates config in all agents.
func (b *backups) Restore(backupId string, dbInfo *DBInfo, args RestoreArgs) (names.Tag, error) {
	meta, backupReader, err := b.Get(backupId)
	if err != nil {
		return nil, errors.Annotatef(err, "could not fetch backup %q", backupId)
	}

	defer backupReader.Close()

	workspace, err := NewArchiveWorkspaceReader(backupReader)
	if err != nil {
		return nil, errors.Annotate(err, "cannot unpack backup file")
	}
	defer workspace.Close()

	// This might actually work, but we don't have a guarantee so we don't allow it.
	if meta.Origin.Series != args.NewInstSeries {
		return nil, errors.Errorf("cannot restore a backup made in a machine with series %q into a machine with series %q, %#v", meta.Origin.Series, args.NewInstSeries, meta)
	}

	// TODO(perrito666) Create a compatibility table of sorts.
	vers := meta.Origin.Version
	if vers.Major != 2 {
		return nil, errors.Errorf("Juju version %v cannot restore backups made using Juju version %v", version.Current.Minor, vers)
	}
	backupMachine := names.NewMachineTag(meta.Origin.Machine)

	// The path for the config file might change if the tag changed
	// and also the rest of the path, so we assume as little as possible.
	oldDatadir, err := paths.DataDir(args.NewInstSeries)
	if err != nil {
		return nil, errors.Annotate(err, "cannot determine DataDir for the restored machine")
	}

	var oldAgentConfig agent.ConfigSetterWriter
	oldAgentConfigFile := agent.ConfigPath(oldDatadir, args.NewInstTag)
	if oldAgentConfig, err = agent.ReadConfig(oldAgentConfigFile); err != nil {
		return nil, errors.Annotate(err, "cannot load old agent config from disk")
	}

	logger.Infof("stopping juju-db")
	if err = mongo.StopService(); err != nil {
		return nil, errors.Annotate(err, "failed to stop mongo")
	}

	// delete all the files to be replaced
	if err := PrepareMachineForRestore(oldAgentConfig.MongoVersion()); err != nil {
		return nil, errors.Annotate(err, "cannot delete existing files")
	}
	logger.Infof("deleted old files to place new")

	if err := workspace.UnpackFilesBundle(filesystemRoot()); err != nil {
		return nil, errors.Annotate(err, "cannot obtain system files from backup")
	}
	logger.Infof("placed new restore files")

	var agentConfig agent.ConfigSetterWriter
	// The path for the config file might change if the tag changed
	// and also the rest of the path, so we assume as little as possible.
	datadir, err := paths.DataDir(args.NewInstSeries)
	if err != nil {
		return nil, errors.Annotate(err, "cannot determine DataDir for the restored machine")
	}
	agentConfigFile := agent.ConfigPath(datadir, backupMachine)
	if agentConfig, err = agent.ReadConfig(agentConfigFile); err != nil {
		return nil, errors.Annotate(err, "cannot load agent config from disk")
	}
	ssi, ok := agentConfig.StateServingInfo()
	if !ok {
		return nil, errors.Errorf("cannot determine state serving info")
	}
	APIHostPorts := network.NewHostPorts(ssi.APIPort, args.PrivateAddress, args.PublicAddress)
	agentConfig.SetAPIHostPorts([][]network.HostPort{APIHostPorts})
	if err := agentConfig.Write(); err != nil {
		return nil, errors.Annotate(err, "cannot write new agent configuration")
	}
	logger.Infof("wrote new agent config for restore")

	if backupMachine.Id() != "0" {
		logger.Infof("extra work needed backup belongs to %q machine", backupMachine.String())
		serviceName := "jujud-" + agentConfig.Tag().String()
		aInfo := service.NewMachineAgentInfo(
			agentConfig.Tag().Id(),
			dataDir,
			paths.MustSucceed(paths.LogDir(args.NewInstSeries)),
		)

		// TODO(perrito666) renderer should have a RendererForSeries, for the moment
		// restore only works on linuxes.
		renderer, _ := shell.NewRenderer("bash")
		serviceAgentConf := service.AgentConf(aInfo, renderer)
		svc, err := service.NewService(serviceName, serviceAgentConf, args.NewInstSeries)
		if err != nil {
			return nil, errors.Annotate(err, "cannot generate service for the restored agent.")
//.........这里部分代码省略.........

type customDataSuite struct {
	testing.BaseSuite
}

var _ = gc.Suite(&customDataSuite{})

func must(s string, err error) string {
	if err != nil {
		panic(err)
	}
	return s
}

var logDir = must(paths.LogDir("precise"))
var metricsSpoolDir = must(paths.MetricsSpoolDir("precise"))
var dataDir = must(paths.DataDir("precise"))
var cloudInitOutputLog = path.Join(logDir, "cloud-init-output.log")

// makeInstanceConfig produces a valid cloudinit machine config.
func makeInstanceConfig(c *gc.C) *instancecfg.InstanceConfig {
	machineId := "0"
	machineTag := names.NewMachineTag(machineId)
	return &instancecfg.InstanceConfig{
		MachineId:       machineId,
		MachineNonce:    "gxshasqlnng",
		DataDir:         dataDir,
		LogDir:          logDir,
		MetricsSpoolDir: metricsSpoolDir,
		Jobs: []multiwatcher.MachineJob{
			multiwatcher.JobManageEnviron,
			multiwatcher.JobHostUnits,

	"github.com/juju/juju/juju/paths"
	"github.com/juju/juju/mongo"
	"github.com/juju/juju/network"
	"github.com/juju/juju/state/api"
	"github.com/juju/juju/state/api/params"
	"github.com/juju/juju/version"
)

var logger = loggo.GetLogger("juju.agent")

// logDir returns a filesystem path to the location where juju
// may create a folder containing its logs
var logDir = paths.MustSucceed(paths.LogDir(version.Current.Series))

// dataDir returns the default data directory for this running system
var dataDir = paths.MustSucceed(paths.DataDir(version.Current.Series))

// DefaultLogDir defines the default log directory for juju agents.
// It's defined as a variable so it could be overridden in tests.
var DefaultLogDir = path.Join(logDir, "juju")

// DefaultDataDir defines the default data directory for juju agents.
// It's defined as a variable so it could be overridden in tests.
var DefaultDataDir = dataDir

// SystemIdentity is the name of the file where the environment SSH key is kept.
const SystemIdentity = "system-identity"

const (
	LxcBridge        = "LXC_BRIDGE"
	ProviderType     = "PROVIDER_TYPE"

// Restore handles either returning or creating a state server to a backed up status:
// * extracts the content of the given backup file and:
// * runs mongorestore with the backed up mongo dump
// * updates and writes configuration files
// * updates existing db entries to make sure they hold no references to
// old instances
// * updates config in all agents.
func (b *backups) Restore(backupId string, args RestoreArgs) error {
	meta, backupReader, err := b.Get(backupId)
	if err != nil {
		return errors.Annotatef(err, "could not fetch backup %q", backupId)
	}

	defer backupReader.Close()

	workspace, err := NewArchiveWorkspaceReader(backupReader)
	if err != nil {
		return errors.Annotate(err, "cannot unpack backup file")
	}
	defer workspace.Close()

	// TODO(perrito666) Create a compatibility table of sorts.
	version := meta.Origin.Version
	backupMachine := names.NewMachineTag(meta.Origin.Machine)

	// delete all the files to be replaced
	if err := PrepareMachineForRestore(); err != nil {
		return errors.Annotate(err, "cannot delete existing files")
	}

	if err := workspace.UnpackFilesBundle(filesystemRoot()); err != nil {
		return errors.Annotate(err, "cannot obtain system files from backup")
	}

	if err := updateBackupMachineTag(backupMachine, args.NewInstTag); err != nil {
		return errors.Annotate(err, "cannot update paths to reflect current machine id")
	}

	var agentConfig agent.ConfigSetterWriter
	// The path for the config file might change if the tag changed
	// and also the rest of the path, so we assume as little as possible.
	datadir, err := paths.DataDir(args.NewInstSeries)
	if err != nil {
		return errors.Annotate(err, "cannot determine DataDir for the restored machine")
	}
	agentConfigFile := agent.ConfigPath(datadir, args.NewInstTag)
	if agentConfig, err = agent.ReadConfig(agentConfigFile); err != nil {
		return errors.Annotate(err, "cannot load agent config from disk")
	}
	ssi, ok := agentConfig.StateServingInfo()
	if !ok {
		return errors.Errorf("cannot determine state serving info")
	}
	// The machine tag might have changed, we update it.
	agentConfig.SetValue("tag", args.NewInstTag.String())
	apiHostPorts := [][]network.HostPort{
		network.NewHostPorts(ssi.APIPort, args.PrivateAddress),
	}
	agentConfig.SetAPIHostPorts(apiHostPorts)
	if err := agentConfig.Write(); err != nil {
		return errors.Annotate(err, "cannot write new agent configuration")
	}

	// Restore mongodb from backup
	if err := placeNewMongo(workspace.DBDumpDir, version); err != nil {
		return errors.Annotate(err, "error restoring state from backup")
	}

	// Re-start replicaset with the new value for server address
	dialInfo, err := newDialInfo(args.PrivateAddress, agentConfig)
	if err != nil {
		return errors.Annotate(err, "cannot produce dial information")
	}

	memberHostPort := fmt.Sprintf("%s:%d", args.PrivateAddress, ssi.StatePort)
	err = resetReplicaSet(dialInfo, memberHostPort)
	if err != nil {
		return errors.Annotate(err, "cannot reset replicaSet")
	}

	err = updateMongoEntries(args.NewInstId, args.NewInstTag.Id(), backupMachine.Id(), dialInfo)
	if err != nil {
		return errors.Annotate(err, "cannot update mongo entries")
	}

	// From here we work with the restored state server
	mgoInfo, ok := agentConfig.MongoInfo()
	if !ok {
		return errors.Errorf("cannot retrieve info to connect to mongo")
	}

	st, err := newStateConnection(mgoInfo)
	if err != nil {
		return errors.Trace(err)
	}
	defer st.Close()

	machine, err := st.Machine(args.NewInstTag.Id())
	if err != nil {
		return errors.Trace(err)
//.........这里部分代码省略.........

func (u *UpgradeMongoCommand) run() (err error) {
	dataDir, err := paths.DataDir(u.series)
	if err != nil {
		return errors.Annotatef(err, "cannot determine data dir for %q", u.series)
	}
	if u.configFilePath == "" {
		machineTag, err := names.ParseMachineTag(u.machineTag)
		if err != nil {
			return errors.Annotatef(err, "%q is not a valid machine tag", u.machineTag)
		}
		u.configFilePath = agent.ConfigPath(dataDir, machineTag)
	}
	u.agentConfig, err = agent.ReadConfig(u.configFilePath)
	if err != nil {
		return errors.Annotatef(err, "cannot read config file in %q", u.configFilePath)
	}

	current := u.agentConfig.MongoVersion()

	agentServiceName := u.agentConfig.Value(agent.AgentServiceName)
	if agentServiceName == "" {
		// For backwards compatibility, handle lack of AgentServiceName.
		agentServiceName = u.osGetenv("UPSTART_JOB")
	}
	if agentServiceName == "" {
		return errors.New("cannot determine juju service name")
	}
	svc, err := u.discoverService(agentServiceName, common.Conf{})
	if err != nil {
		return errors.Annotate(err, "cannot determine juju service")
	}
	if err := svc.Stop(); err != nil {
		return errors.Annotate(err, "cannot stop juju to begin migration")
	}
	defer func() {
		svcErr := svc.Start()
		if err != nil {
			err = errors.Annotatef(err, "failed upgrade and juju start after rollbacking upgrade: %v", svcErr)
		} else {
			err = errors.Annotate(svcErr, "could not start juju after upgrade")
		}
	}()
	if !u.slave {
		defer u.replicaAdd()
	}
	if u.rollback {
		origin := u.agentConfig.Value(KeyUpgradeBackup)
		if origin == "" {
			return errors.New("no available backup")
		}
		return u.rollbackCopyBackup(dataDir, origin)
	}

	u.tmpDir, err = u.createTempDir()
	if err != nil {
		return errors.Annotate(err, "could not create a temporary directory for the migration")
	}

	logger.Infof("begin migration to mongo 3")

	if err := u.satisfyPrerequisites(u.series); err != nil {
		return errors.Annotate(err, "cannot satisfy pre-requisites for the migration")
	}
	if current == mongo.Mongo24 || current == mongo.MongoUpgrade {
		if u.slave {
			return u.upgradeSlave(dataDir)
		}
		u.replicaRemove()
		if err := u.maybeUpgrade24to26(dataDir); err != nil {
			defer func() {
				if u.backupPath == "" {
					return
				}
				logger.Infof("will roll back after failed 2.6 upgrade")
				if err := u.rollbackCopyBackup(dataDir, u.backupPath); err != nil {
					logger.Errorf("could not rollback the upgrade: %v", err)
				}
			}()
			return errors.Annotate(err, "cannot upgrade from mongo 2.4 to 2.6")
		}
		current = mongo.Mongo26
	}
	if current == mongo.Mongo26 || current.StorageEngine != mongo.WiredTiger {
		if err := u.maybeUpgrade26to3x(dataDir); err != nil {
			defer func() {
				if u.backupPath == "" {
					return
				}
				logger.Infof("will roll back after failed 3.0 upgrade")
				if err := u.rollbackCopyBackup(dataDir, u.backupPath); err != nil {
					logger.Errorf("could not rollback the upgrade: %v", err)
				}
			}()
			return errors.Annotate(err, "cannot upgrade from mongo 2.6 to 3")
		}
	}
	return nil
}

// Restore handles either returning or creating a controller to a backed up status:
// * extracts the content of the given backup file and:
// * runs mongorestore with the backed up mongo dump
// * updates and writes configuration files
// * updates existing db entries to make sure they hold no references to
// old instances
// * updates config in all agents.
func (b *backups) Restore(backupId string, args RestoreArgs) (names.Tag, error) {
	meta, backupReader, err := b.Get(backupId)
	if err != nil {
		return nil, errors.Annotatef(err, "could not fetch backup %q", backupId)
	}

	defer backupReader.Close()

	workspace, err := NewArchiveWorkspaceReader(backupReader)
	if err != nil {
		return nil, errors.Annotate(err, "cannot unpack backup file")
	}
	defer workspace.Close()

	// TODO(perrito666) Create a compatibility table of sorts.
	version := meta.Origin.Version
	backupMachine := names.NewMachineTag(meta.Origin.Machine)

	if err := mongo.StopService(); err != nil {
		return nil, errors.Annotate(err, "cannot stop mongo to replace files")
	}

	// delete all the files to be replaced
	if err := PrepareMachineForRestore(); err != nil {
		return nil, errors.Annotate(err, "cannot delete existing files")
	}
	logger.Infof("deleted old files to place new")

	if err := workspace.UnpackFilesBundle(filesystemRoot()); err != nil {
		return nil, errors.Annotate(err, "cannot obtain system files from backup")
	}
	logger.Infof("placed new files")

	var agentConfig agent.ConfigSetterWriter
	// The path for the config file might change if the tag changed
	// and also the rest of the path, so we assume as little as possible.
	datadir, err := paths.DataDir(args.NewInstSeries)
	if err != nil {
		return nil, errors.Annotate(err, "cannot determine DataDir for the restored machine")
	}
	agentConfigFile := agent.ConfigPath(datadir, backupMachine)
	if agentConfig, err = agent.ReadConfig(agentConfigFile); err != nil {
		return nil, errors.Annotate(err, "cannot load agent config from disk")
	}
	ssi, ok := agentConfig.StateServingInfo()
	if !ok {
		return nil, errors.Errorf("cannot determine state serving info")
	}
	APIHostPorts := network.NewHostPorts(ssi.APIPort, args.PrivateAddress)
	agentConfig.SetAPIHostPorts([][]network.HostPort{APIHostPorts})
	if err := agentConfig.Write(); err != nil {
		return nil, errors.Annotate(err, "cannot write new agent configuration")
	}
	logger.Infof("wrote new agent config")

	if backupMachine.Id() != "0" {
		logger.Infof("extra work needed backup belongs to %q machine", backupMachine.String())
		serviceName := "jujud-" + agentConfig.Tag().String()
		aInfo := service.NewMachineAgentInfo(
			agentConfig.Tag().Id(),
			dataDir,
			paths.MustSucceed(paths.LogDir(args.NewInstSeries)),
		)

		// TODO(perrito666) renderer should have a RendererForSeries, for the moment
		// restore only works on linuxes.
		renderer, _ := shell.NewRenderer("bash")
		serviceAgentConf := service.AgentConf(aInfo, renderer)
		svc, err := service.NewService(serviceName, serviceAgentConf, args.NewInstSeries)
		if err != nil {
			return nil, errors.Annotate(err, "cannot generate service for the restored agent.")
		}
		if err := svc.Install(); err != nil {
			return nil, errors.Annotate(err, "cannot install service for the restored agent.")
		}
		logger.Infof("new machine service")
	}

	logger.Infof("mongo service will be reinstalled to ensure its presence")
	if err := ensureMongoService(agentConfig); err != nil {
		return nil, errors.Annotate(err, "failed to reinstall service for juju-db")
	}

	logger.Infof("new mongo will be restored")
	// Restore mongodb from backup
	if err := placeNewMongoService(workspace.DBDumpDir, version); err != nil {
		return nil, errors.Annotate(err, "error restoring state from backup")
	}

	// Re-start replicaset with the new value for server address
	dialInfo, err := newDialInfo(args.PrivateAddress, agentConfig)
	if err != nil {
		return nil, errors.Annotate(err, "cannot produce dial information")
//.........这里部分代码省略.........

func jujuDataDir(series string) string {
	return must(paths.DataDir(series))
}