Esempio n. 1
0
// loadImage loads an os image from the blobstore,
// downloading and caching it if necessary.
func (h *imagesDownloadHandler) loadImage(st *state.State, envuuid, kind, series, arch string) (
	*imagestorage.Metadata, io.ReadCloser, error,
) {
	// We want to ensure that if an image needs to be downloaded and cached,
	// this only happens once.
	imageIdent := fmt.Sprintf("image-%s-%s-%s-%s", envuuid, kind, series, arch)
	lockDir := filepath.Join(h.dataDir, "locks")
	lock, err := fslock.NewLock(lockDir, imageIdent, fslock.Defaults())
	if err != nil {
		return nil, nil, errors.Trace(err)
	}
	lock.Lock("fetch and cache image " + imageIdent)
	defer lock.Unlock()
	storage := st.ImageStorage()
	metadata, imageReader, err := storage.Image(kind, series, arch)
	// Not in storage, so go fetch it.
	if errors.IsNotFound(err) {
		if err := h.fetchAndCacheLxcImage(storage, envuuid, series, arch); err != nil {
			return nil, nil, errors.Annotate(err, "error fetching and caching image")
		}
		err = networkOperationWitDefaultRetries(func() error {
			metadata, imageReader, err = storage.Image(string(instance.LXC), series, arch)
			return err
		}, "streaming os image from blobstore")()
	}
	if err != nil {
		return nil, nil, errors.Trace(err)
	}
	return metadata, imageReader, nil
}
Esempio n. 2
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func (s *imageSuite) getImageFromStorage(c *gc.C, st *state.State, kind, series, arch string) (*imagestorage.Metadata, []byte) {
	storage := st.ImageStorage()
	metadata, r, err := storage.Image(kind, series, arch)
	c.Assert(err, gc.IsNil)
	data, err := ioutil.ReadAll(r)
	r.Close()
	c.Assert(err, gc.IsNil)
	return metadata, data
}
Esempio n. 3
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func (s *imageSuite) storeFakeImage(c *gc.C, st *state.State, kind, series, arch string) {
	storage := st.ImageStorage()
	metadata := &imagestorage.Metadata{
		ModelUUID: st.ModelUUID(),
		Kind:      kind,
		Series:    series,
		Arch:      arch,
		Size:      int64(len(testImageData)),
		SHA256:    testImageChecksum,
		SourceURL: "http://path",
	}
	err := storage.AddImage(strings.NewReader(testImageData), metadata)
	c.Assert(err, gc.IsNil)
}