Example #1
0
// getOrCreateBlobWriter will track which blobs are currently being downloaded and enable client requesting
// the same blob concurrently to read from the existing stream.
func getOrCreateBlobWriter(ctx context.Context, blobs distribution.BlobService, desc distribution.Descriptor) (distribution.BlobWriter, bool, cleanupFunc, error) {
	mu.Lock()
	defer mu.Unlock()
	dgst := desc.Digest

	cleanup := func() {
		mu.Lock()
		defer mu.Unlock()
		inflight[dgst].refCount--

		if inflight[dgst].refCount == 0 {
			defer delete(inflight, dgst)
			_, err := inflight[dgst].bw.Commit(ctx, desc)
			if err != nil {
				// There is a narrow race here where Commit can be called while this blob's TTL is expiring
				// and its being removed from storage.  In that case, the client stream will continue
				// uninterruped and the blob will be pulled through on the next request, so just log it
				context.GetLogger(ctx).Errorf("Error committing blob: %q", err)
			}

		}
	}

	var bw distribution.BlobWriter
	_, ok := inflight[dgst]
	if ok {
		bw = inflight[dgst].bw
		inflight[dgst].refCount++
		return bw, false, cleanup, nil
	}

	var err error
	bw, err = blobs.Create(ctx)
	if err != nil {
		return nil, false, nil, err
	}

	inflight[dgst] = &inflightBlob{refCount: 1, bw: bw}
	return bw, true, cleanup, nil
}
Example #2
0
func (p *v2Pusher) pushV2Image(bs distribution.BlobService, img *image.Image) (digest.Digest, error) {
	out := p.config.OutStream

	out.Write(p.sf.FormatProgress(stringid.TruncateID(img.ID), "Preparing", nil))

	image, err := p.graph.Get(img.ID)
	if err != nil {
		return "", err
	}
	arch, err := p.graph.TarLayer(image)
	if err != nil {
		return "", err
	}
	defer arch.Close()

	// Send the layer
	layerUpload, err := bs.Create(context.Background())
	if err != nil {
		return "", err
	}
	defer layerUpload.Close()

	reader := progressreader.New(progressreader.Config{
		In:        ioutil.NopCloser(arch), // we'll take care of close here.
		Out:       out,
		Formatter: p.sf,

		// TODO(stevvooe): This may cause a size reporting error. Try to get
		// this from tar-split or elsewhere. The main issue here is that we
		// don't want to buffer to disk *just* to calculate the size.
		Size: img.Size,

		NewLines: false,
		ID:       stringid.TruncateID(img.ID),
		Action:   "Pushing",
	})

	digester := digest.Canonical.New()
	// HACK: The MultiWriter doesn't write directly to layerUpload because
	// we must make sure the ReadFrom is used, not Write. Using Write would
	// send a PATCH request for every Write call.
	pipeReader, pipeWriter := io.Pipe()
	// Use a bufio.Writer to avoid excessive chunking in HTTP request.
	bufWriter := bufio.NewWriterSize(io.MultiWriter(pipeWriter, digester.Hash()), compressionBufSize)
	compressor := gzip.NewWriter(bufWriter)

	go func() {
		_, err := io.Copy(compressor, reader)
		if err == nil {
			err = compressor.Close()
		}
		if err == nil {
			err = bufWriter.Flush()
		}
		if err != nil {
			pipeWriter.CloseWithError(err)
		} else {
			pipeWriter.Close()
		}
	}()

	out.Write(p.sf.FormatProgress(stringid.TruncateID(img.ID), "Pushing", nil))
	nn, err := layerUpload.ReadFrom(pipeReader)
	pipeReader.Close()
	if err != nil {
		return "", err
	}

	dgst := digester.Digest()
	if _, err := layerUpload.Commit(context.Background(), distribution.Descriptor{Digest: dgst}); err != nil {
		return "", err
	}

	logrus.Debugf("uploaded layer %s (%s), %d bytes", img.ID, dgst, nn)
	out.Write(p.sf.FormatProgress(stringid.TruncateID(img.ID), "Pushed", nil))

	return dgst, nil
}