// setPrivateMetadataSources sets the default tools metadata source
// for tools syncing, and adds an image metadata source after verifying
// the contents.
func setPrivateMetadataSources(metadataDir string) ([]*imagemetadata.ImageMetadata, error) {
	logger.Infof("Setting default tools and image metadata sources: %s", metadataDir)
	tools.DefaultBaseURL = metadataDir

	imageMetadataDir := filepath.Join(metadataDir, storage.BaseImagesPath)
	if _, err := os.Stat(imageMetadataDir); err != nil {
		if !os.IsNotExist(err) {
			return nil, errors.Annotate(err, "cannot access image metadata")
		}
		return nil, nil
	}

	baseURL := fmt.Sprintf("file://%s", filepath.ToSlash(imageMetadataDir))
	publicKey, _ := simplestreams.UserPublicSigningKey()
	datasource := simplestreams.NewURLSignedDataSource("bootstrap metadata", baseURL, publicKey, utils.NoVerifySSLHostnames, simplestreams.CUSTOM_CLOUD_DATA, false)

	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	existingMetadata, _, err := imagemetadata.Fetch([]simplestreams.DataSource{datasource}, imageConstraint)
	if err != nil && !errors.IsNotFound(err) {
		return nil, errors.Annotate(err, "cannot read image metadata")
	}

	// Add an image metadata datasource for constraint validation, etc.
	environs.RegisterUserImageDataSourceFunc("bootstrap metadata", func(environs.Environ) (simplestreams.DataSource, error) {
		return datasource, nil
	})
	logger.Infof("custom image metadata added to search path")
	return existingMetadata, nil
}

// FindInstanceSpec returns an InstanceSpec satisfying the supplied instanceConstraint.
func (env *joyentEnviron) FindInstanceSpec(ic *instances.InstanceConstraint) (*instances.InstanceSpec, error) {
	// Require at least one VCPU so we get KVM rather than smart package.
	if ic.Constraints.CpuCores == nil {
		ic.Constraints.CpuCores = &defaultCpuCores
	}
	allInstanceTypes, err := env.listInstanceTypes()
	if err != nil {
		return nil, err
	}
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{ic.Region, env.Ecfg().SdcUrl()},
		Series:    []string{ic.Series},
		Arches:    ic.Arches,
	})
	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return nil, err
	}

	matchingImages, _, err := imagemetadata.Fetch(sources, imageConstraint, signedImageDataOnly)
	if err != nil {
		return nil, err
	}
	images := instances.ImageMetadataToImages(matchingImages)
	spec, err := instances.FindInstanceSpec(images, ic, allInstanceTypes)
	if err != nil {
		return nil, err
	}
	return spec, nil
}

func SetImageMetadata(env environs.Environ, series, arches []string, out *[]*imagemetadata.ImageMetadata) error {
	hasRegion, ok := env.(simplestreams.HasRegion)
	if !ok {
		return nil
	}
	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return errors.Trace(err)
	}
	region, err := hasRegion.Region()
	if err != nil {
		return errors.Trace(err)
	}
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: region,
		Series:    series,
		Arches:    arches,
		Stream:    env.Config().ImageStream(),
	})
	imageMetadata, _, err := imagemetadata.Fetch(sources, imageConstraint)
	if err != nil {
		return errors.Trace(err)
	}
	*out = imageMetadata
	return nil
}

func (s *simplestreamsSuite) TestFetch(c *gc.C) {
	for i, t := range fetchTests {
		c.Logf("test %d", i)
		cloudSpec := simplestreams.CloudSpec{t.region, "https://ec2.us-east-1.amazonaws.com"}
		if t.region == "" {
			cloudSpec = simplestreams.EmptyCloudSpec
		}
		imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
			CloudSpec: cloudSpec,
			Series:    []string{"precise"},
			Arches:    t.arches,
		})
		// Add invalid datasource and check later that resolveInfo is correct.
		invalidSource := simplestreams.NewURLDataSource("invalid", "file://invalid", utils.VerifySSLHostnames, simplestreams.DEFAULT_CLOUD_DATA, s.RequireSigned)
		images, resolveInfo, err := imagemetadata.Fetch(
			[]simplestreams.DataSource{invalidSource, s.Source}, imageConstraint)
		if !c.Check(err, jc.ErrorIsNil) {
			continue
		}
		for _, testImage := range t.images {
			testImage.Version = t.version
		}
		c.Check(images, gc.DeepEquals, t.images)
		c.Check(resolveInfo, gc.DeepEquals, &simplestreams.ResolveInfo{
			Source:    "test roundtripper",
			Signed:    s.RequireSigned,
			IndexURL:  "test:/streams/v1/index.json",
			MirrorURL: "",
		})
	}
}

// setPrivateMetadataSources sets the default tools metadata source
// for tools syncing, and adds an image metadata source after verifying
// the contents.
func setPrivateMetadataSources(env environs.Environ, metadataDir string) ([]*imagemetadata.ImageMetadata, error) {
	logger.Infof("Setting default tools and image metadata sources: %s", metadataDir)
	tools.DefaultBaseURL = metadataDir

	imageMetadataDir := filepath.Join(metadataDir, storage.BaseImagesPath)
	if _, err := os.Stat(imageMetadataDir); err != nil {
		if !os.IsNotExist(err) {
			return nil, errors.Annotate(err, "cannot access image metadata")
		}
		return nil, nil
	}

	baseURL := fmt.Sprintf("file://%s", filepath.ToSlash(imageMetadataDir))
	datasource := simplestreams.NewURLDataSource("bootstrap metadata", baseURL, utils.NoVerifySSLHostnames)

	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	existingMetadata, _, err := imagemetadata.Fetch(
		[]simplestreams.DataSource{datasource}, imageConstraint, false)
	if err != nil && !errors.IsNotFound(err) {
		return nil, errors.Annotate(err, "cannot read image metadata")
	}

	// Add an image metadata datasource for constraint validation, etc.
	// TODO (anastasiamac 2015-09-26) Delete when search path is modified to look
	// into state first.
	environs.RegisterUserImageDataSourceFunc("bootstrap metadata", func(environs.Environ) (simplestreams.DataSource, error) {
		return datasource, nil
	})
	logger.Infof("custom image metadata added to search path")
	return existingMetadata, nil
}

func (s *signedSuite) TestSignedImageMetadataInvalidSignature(c *gc.C) {
	signedSource := simplestreams.NewURLDataSource("test", "test://host/signed", utils.VerifySSLHostnames, simplestreams.DEFAULT_CLOUD_DATA, true)
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{"us-east-1", "https://ec2.us-east-1.amazonaws.com"},
		Series:    []string{"precise"},
		Arches:    []string{"amd64"},
	})
	imagemetadata.SetSigningPublicKey(s.origKey)
	_, _, err := imagemetadata.Fetch([]simplestreams.DataSource{signedSource}, imageConstraint)
	c.Assert(err, gc.ErrorMatches, "cannot read index data.*")
}

func assertFetch(c *gc.C, stor storage.Storage, series, arch, region, endpoint, id string) {
	cons := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{region, endpoint},
		Series:    []string{series},
		Arches:    []string{arch},
	})
	dataSource := storage.NewStorageSimpleStreamsDataSource("test datasource", stor, "images")
	metadata, _, err := imagemetadata.Fetch([]simplestreams.DataSource{dataSource}, cons, false)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(metadata, gc.HasLen, 1)
	c.Assert(metadata[0].Id, gc.Equals, id)
}

func assertFetch(c *gc.C, stor storage.Storage, series, arch, region, endpoint string, ids ...string) {
	cons := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{region, endpoint},
		Series:    []string{series},
		Arches:    []string{arch},
	})
	dataSource := storage.NewStorageSimpleStreamsDataSource("test datasource", stor, "images", simplestreams.DEFAULT_CLOUD_DATA, false)
	metadata, _, err := imagemetadata.Fetch([]simplestreams.DataSource{dataSource}, cons)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(metadata, gc.HasLen, len(ids))
	for i, id := range ids {
		c.Assert(metadata[i].Id, gc.Equals, id)
	}
}

// SupportedArchitectures returns all the image architectures for env matching the constraints.
func SupportedArchitectures(env environs.Environ, imageConstraint *imagemetadata.ImageConstraint) ([]string, error) {
	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return nil, err
	}
	matchingImages, _, err := imagemetadata.Fetch(sources, imageConstraint, false)
	if err != nil {
		return nil, err
	}
	var arches = set.NewStrings()
	for _, im := range matchingImages {
		arches.Add(im.Arch)
	}
	return arches.Values(), nil
}

func (api *API) retrievePublished() error {
	envCfg, err := api.metadata.ModelConfig()
	if err != nil {
		return errors.Annotatef(err, "getting environ config")
	}
	env, err := environs.New(envCfg)
	if err != nil {
		return errors.Annotatef(err, "getting environ")
	}

	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return errors.Annotatef(err, "getting cloud specific image metadata sources")
	}

	cons := envmetadata.NewImageConstraint(simplestreams.LookupParams{})
	if inst, ok := env.(simplestreams.HasRegion); !ok {
		// Published image metadata for some providers are in simple streams.
		// Providers that do not rely on simplestreams, don't need to do anything here.
		return nil
	} else {
		// If we can determine current region,
		// we want only metadata specific to this region.
		cloud, err := inst.Region()
		if err != nil {
			return errors.Annotatef(err, "getting cloud specific region information")
		}
		cons.CloudSpec = cloud
	}

	// We want all relevant metadata from all data sources.
	for _, source := range sources {
		logger.Debugf("looking in data source %v", source.Description())
		metadata, info, err := envmetadata.Fetch([]simplestreams.DataSource{source}, cons)
		if err != nil {
			// Do not stop looking in other data sources if there is an issue here.
			logger.Errorf("encountered %v while getting published images metadata from %v", err, source.Description())
			continue
		}
		err = api.saveAll(info, source.Priority(), metadata)
		if err != nil {
			// Do not stop looking in other data sources if there is an issue here.
			logger.Errorf("encountered %v while saving published images metadata from %v", err, source.Description())
		}
	}
	return nil
}

// saveCustomImageMetadata reads the custom image metadata from disk,
// and saves it in state server.
func (c *BootstrapCommand) saveCustomImageMetadata(st *state.State) error {
	logger.Debugf("saving custom image metadata from %q", c.ImageMetadataDir)

	baseURL := fmt.Sprintf("file://%s", filepath.ToSlash(c.ImageMetadataDir))
	datasource := simplestreams.NewURLDataSource("bootstrap metadata", baseURL, utils.NoVerifySSLHostnames)

	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	existingMetadata, _, err := imagemetadata.Fetch(
		[]simplestreams.DataSource{datasource}, imageConstraint, false)
	if err != nil && !errors.IsNotFound(err) {
		return errors.Annotate(err, "cannot read image metadata")
	}

	if len(existingMetadata) == 0 {
		return nil
	}
	msg := ""
	for _, one := range existingMetadata {
		m := cloudimagemetadata.Metadata{
			cloudimagemetadata.MetadataAttributes{
				Stream:          one.Stream,
				Region:          one.RegionName,
				Arch:            one.Arch,
				VirtType:        one.VirtType,
				RootStorageType: one.Storage,
				Source:          "custom",
			},
			one.Id,
		}
		s, err := seriesFromVersion(one.Version)
		if err != nil {
			return errors.Annotatef(err, "cannot determine series for version %v", one.Version)
		}
		m.Series = s
		err = st.CloudImageMetadataStorage.SaveMetadata(m)
		if err != nil {
			return errors.Annotatef(err, "cannot cache image metadata %v", m)
		}
	}
	if len(msg) > 0 {
		return errors.New(msg)
	}
	return nil
}

func (s *signedSuite) TestSignedImageMetadata(c *gc.C) {
	signedSource := simplestreams.NewURLSignedDataSource("test", "test://host/signed", sstesting.SignedMetadataPublicKey, utils.VerifySSLHostnames, simplestreams.DEFAULT_CLOUD_DATA, true)
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{"us-east-1", "https://ec2.us-east-1.amazonaws.com"},
		Series:    []string{"precise"},
		Arches:    []string{"amd64"},
	})
	images, resolveInfo, err := imagemetadata.Fetch([]simplestreams.DataSource{signedSource}, imageConstraint)
	c.Assert(err, jc.ErrorIsNil)
	c.Assert(len(images), gc.Equals, 1)
	c.Assert(images[0].Id, gc.Equals, "ami-123456")
	c.Check(resolveInfo, gc.DeepEquals, &simplestreams.ResolveInfo{
		Source:    "test",
		Signed:    true,
		IndexURL:  "test://host/signed/streams/v1/index.sjson",
		MirrorURL: "",
	})
}

// findInstanceSpec returns an InstanceSpec satisfying the supplied instanceConstraint.
func findInstanceSpec(
	sources []simplestreams.DataSource, stream string, ic *instances.InstanceConstraint) (*instances.InstanceSpec, error) {

	// If the instance type is set, don't also set a default CPU power
	// as this is implied.
	cons := ic.Constraints
	if cons.CpuPower == nil && (cons.InstanceType == nil || *cons.InstanceType == "") {
		ic.Constraints.CpuPower = instances.CpuPower(defaultCpuPower)
	}
	ec2Region := allRegions[ic.Region]
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{ic.Region, ec2Region.EC2Endpoint},
		Series:    []string{ic.Series},
		Arches:    ic.Arches,
		Stream:    stream,
	})
	matchingImages, _, err := imagemetadata.Fetch(sources, imageConstraint, signedImageDataOnly)
	if err != nil {
		return nil, err
	}
	if len(matchingImages) == 0 {
		logger.Warningf("no matching image meta data for constraints: %v", ic)
	}
	suitableImages := filterImages(matchingImages, ic)
	images := instances.ImageMetadataToImages(suitableImages)

	// Make a copy of the known EC2 instance types, filling in the cost for the specified region.
	regionCosts := allRegionCosts[ic.Region]
	if len(regionCosts) == 0 && len(allRegionCosts) > 0 {
		return nil, fmt.Errorf("no instance types found in %s", ic.Region)
	}

	var itypesWithCosts []instances.InstanceType
	for _, itype := range allInstanceTypes {
		cost, ok := regionCosts[itype.Name]
		if !ok {
			continue
		}
		itWithCost := itype
		itWithCost.Cost = cost
		itypesWithCosts = append(itypesWithCosts, itWithCost)
	}
	return instances.FindInstanceSpec(images, ic, itypesWithCosts)
}

// findInstanceSpec returns an image and instance type satisfying the constraint.
// The instance type comes from querying the flavors supported by the deployment.
func findInstanceSpec(e *environ, ic *instances.InstanceConstraint) (*instances.InstanceSpec, error) {
	// first construct all available instance types from the supported flavors.
	nova := e.nova()
	flavors, err := nova.ListFlavorsDetail()
	if err != nil {
		return nil, err
	}
	allInstanceTypes := []instances.InstanceType{}
	for _, flavor := range flavors {
		instanceType := instances.InstanceType{
			Id:       flavor.Id,
			Name:     flavor.Name,
			Arches:   ic.Arches,
			Mem:      uint64(flavor.RAM),
			CpuCores: uint64(flavor.VCPUs),
			RootDisk: uint64(flavor.Disk * 1024),
			// tags not currently supported on openstack
		}
		allInstanceTypes = append(allInstanceTypes, instanceType)
	}

	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{ic.Region, e.ecfg().authURL()},
		Series:    []string{ic.Series},
		Arches:    ic.Arches,
		Stream:    e.Config().ImageStream(),
	})
	sources, err := imagemetadata.GetMetadataSources(e)
	if err != nil {
		return nil, err
	}
	// TODO (wallyworld): use an env parameter (default true) to mandate use of only signed image metadata.
	matchingImages, _, err := imagemetadata.Fetch(sources, simplestreams.DefaultIndexPath, imageConstraint, false)
	if err != nil {
		return nil, err
	}
	images := instances.ImageMetadataToImages(matchingImages)
	spec, err := instances.FindInstanceSpec(images, ic, allInstanceTypes)
	if err != nil {
		return nil, err
	}
	return spec, nil
}

// storeImageMetadataFromFiles puts image metadata found in sources into state.
func storeImageMetadataFromFiles(st *state.State, env environs.Environ, source simplestreams.DataSource) error {
	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	if inst, ok := env.(simplestreams.HasRegion); ok {
		// If we can determine current region,
		// we want only metadata specific to this region.
		cloud, err := inst.Region()
		if err != nil {
			return err
		}
		imageConstraint.CloudSpec = cloud
	}

	existingMetadata, info, err := imagemetadata.Fetch([]simplestreams.DataSource{source}, imageConstraint)
	if err != nil && !errors.IsNotFound(err) {
		return errors.Annotate(err, "cannot read image metadata")
	}
	return storeImageMetadataInState(st, info.Source, source.Priority(), existingMetadata)
}

// findMatchingImages queries simplestreams for OS images that match the given
// requirements.
//
// If it finds no matching images, that's an error.
func findMatchingImages(e *azureEnviron, location, series string, arches []string) ([]*imagemetadata.ImageMetadata, error) {
	endpoint := getEndpoint(location)
	constraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{
		CloudSpec: simplestreams.CloudSpec{location, endpoint},
		Series:    []string{series},
		Arches:    arches,
		Stream:    e.Config().ImageStream(),
	})
	sources, err := environs.ImageMetadataSources(e)
	if err != nil {
		return nil, err
	}
	images, _, err := imagemetadata.Fetch(sources, constraint, signedImageDataOnly)
	if len(images) == 0 || errors.IsNotFound(err) {
		return nil, fmt.Errorf("no OS images found for location %q, series %q, architectures %q (and endpoint: %q)", location, series, arches, endpoint)
	} else if err != nil {
		return nil, err
	}
	return images, nil
}

func (api *API) retrievePublished() ([]*envmetadata.ImageMetadata, error) {
	// Get environ
	envCfg, err := api.metadata.EnvironConfig()
	env, err := environs.New(envCfg)
	if err != nil {
		return nil, errors.Trace(err)
	}

	// Get all images metadata sources for this environ.
	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return nil, err
	}

	// We want all metadata.
	cons := envmetadata.NewImageConstraint(simplestreams.LookupParams{})
	metadata, _, err := envmetadata.Fetch(sources, cons, false)
	if err != nil {
		return nil, err
	}
	return metadata, nil
}

// storeImageMetadataFromFiles puts image metadata found in sources into state.
// Declared as var to facilitate tests.
var storeImageMetadataFromFiles = func(st *state.State, env environs.Environ, source simplestreams.DataSource) error {
	// Read the image metadata, as we'll want to upload it to the environment.
	imageConstraint := imagemetadata.NewImageConstraint(simplestreams.LookupParams{})
	if inst, ok := env.(simplestreams.HasRegion); ok {
		// If we can determine current region,
		// we want only metadata specific to this region.
		cloud, err := inst.Region()
		if err != nil {
			return err
		}
		imageConstraint.CloudSpec = cloud
	}

	existingMetadata, info, err := imagemetadata.Fetch([]simplestreams.DataSource{source}, imageConstraint)
	if err != nil && !errors.IsNotFound(err) {
		return errors.Annotate(err, "cannot read image metadata")
	}
	return storeImageMetadataInState(st, info.Source, source.Priority(), existingMetadata)
}

// storeImageMetadataInState writes image metadata into state store.
func storeImageMetadataInState(st *state.State, source string, priority int, existingMetadata []*imagemetadata.ImageMetadata) error {
	if len(existingMetadata) == 0 {
		return nil
	}
	metadataState := make([]cloudimagemetadata.Metadata, len(existingMetadata))
	for i, one := range existingMetadata {
		m := cloudimagemetadata.Metadata{
			cloudimagemetadata.MetadataAttributes{

// imageMetadataFromDataSources finds image metadata that match specified criteria in existing data sources.
func (p *ProvisionerAPI) imageMetadataFromDataSources(env environs.Environ, constraint *imagemetadata.ImageConstraint) ([]params.CloudImageMetadata, error) {
	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return nil, errors.Trace(err)
	}

	cfg := env.Config()
	toModel := func(m *imagemetadata.ImageMetadata, mSeries string, source string, priority int) cloudimagemetadata.Metadata {
		result := cloudimagemetadata.Metadata{
			MetadataAttributes: cloudimagemetadata.MetadataAttributes{
				Region:          m.RegionName,
				Arch:            m.Arch,
				VirtType:        m.VirtType,
				RootStorageType: m.Storage,
				Source:          source,
				Series:          mSeries,
				Stream:          m.Stream,
				Version:         m.Version,
			},
			Priority: priority,
			ImageId:  m.Id,
		}
		// TODO (anastasiamac 2016-08-24) This is a band-aid solution.
		// Once correct value is read from simplestreams, this needs to go.
		// Bug# 1616295
		if result.Stream == "" {
			result.Stream = constraint.Stream
		}
		if result.Stream == "" {
			result.Stream = cfg.ImageStream()
		}
		return result
	}

	var metadataState []cloudimagemetadata.Metadata
	for _, source := range sources {
		logger.Debugf("looking in data source %v", source.Description())
		found, info, err := imagemetadata.Fetch([]simplestreams.DataSource{source}, constraint)
		if err != nil {
			// Do not stop looking in other data sources if there is an issue here.
			logger.Warningf("encountered %v while getting published images metadata from %v", err, source.Description())
			continue
		}
		for _, m := range found {
			mSeries, err := series.VersionSeries(m.Version)
			if err != nil {
				logger.Warningf("could not determine series for image id %s: %v", m.Id, err)
				continue
			}
			metadataState = append(metadataState, toModel(m, mSeries, info.Source, source.Priority()))
		}
	}
	if len(metadataState) > 0 {
		if err := p.st.CloudImageMetadataStorage.SaveMetadata(metadataState); err != nil {
			// No need to react here, just take note
			logger.Warningf("failed to save published image metadata: %v", err)
		}
	}

	// Since we've fallen through to data sources search and have saved all needed images into controller,
	// let's try to get them from controller to avoid duplication of conversion logic here.
	all, err := p.imageMetadataFromState(constraint)
	if err != nil {
		return nil, errors.Annotate(err, "could not read metadata from controller after saving it there from data sources")
	}

	if len(all) == 0 {
		return nil, errors.NotFoundf("image metadata for series %v, arch %v", constraint.Series, constraint.Arches)
	}

	return all, nil
}

	"github.com/juju/juju/instance"
	"github.com/juju/juju/tools"
)

//
// Imlementation of InstanceBroker: methods for starting and stopping instances.
//

var findInstanceImage = func(env *environ, ic *imagemetadata.ImageConstraint) (*imagemetadata.ImageMetadata, error) {

	sources, err := environs.ImageMetadataSources(env)
	if err != nil {
		return nil, err
	}

	matchingImages, _, err := imagemetadata.Fetch(sources, ic, false)
	if err != nil {
		return nil, err
	}
	if len(matchingImages) == 0 {
		return nil, errors.New("no matching image meta data")
	}

	return matchingImages[0], nil
}

// MaintainInstance is specified in the InstanceBroker interface.
func (*environ) MaintainInstance(args environs.StartInstanceParams) error {
	return nil
}