Example #1
0
func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Writer, localName, remoteName, tag string, sf *utils.StreamFormatter, parallel bool) (bool, error) {
	log.Debugf("Pulling tag from V2 registry: %q", tag)
	manifestBytes, err := r.GetV2ImageManifest(remoteName, tag, nil)
	if err != nil {
		return false, err
	}

	manifest, verified, err := s.verifyManifest(eng, manifestBytes)
	if err != nil {
		return false, fmt.Errorf("error verifying manifest: %s", err)
	}

	if len(manifest.FSLayers) != len(manifest.History) {
		return false, fmt.Errorf("length of history not equal to number of layers")
	}

	if verified {
		out.Write(sf.FormatStatus(localName+":"+tag, "The image you are pulling has been verified"))
	} else {
		out.Write(sf.FormatStatus(tag, "Pulling from %s", localName))
	}

	if len(manifest.FSLayers) == 0 {
		return false, fmt.Errorf("no blobSums in manifest")
	}

	downloads := make([]downloadInfo, len(manifest.FSLayers))

	for i := len(manifest.FSLayers) - 1; i >= 0; i-- {
		var (
			sumStr  = manifest.FSLayers[i].BlobSum
			imgJSON = []byte(manifest.History[i].V1Compatibility)
		)

		img, err := image.NewImgJSON(imgJSON)
		if err != nil {
			return false, fmt.Errorf("failed to parse json: %s", err)
		}
		downloads[i].img = img

		// Check if exists
		if s.graph.Exists(img.ID) {
			log.Debugf("Image already exists: %s", img.ID)
			continue
		}

		chunks := strings.SplitN(sumStr, ":", 2)
		if len(chunks) < 2 {
			return false, fmt.Errorf("expected 2 parts in the sumStr, got %#v", chunks)
		}
		sumType, checksum := chunks[0], chunks[1]
		out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Pulling fs layer", nil))

		downloadFunc := func(di *downloadInfo) error {
			log.Debugf("pulling blob %q to V1 img %s", sumStr, img.ID)

			if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {
				if c != nil {
					out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))
					<-c
					out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
				} else {
					log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)
				}
			} else {
				defer s.poolRemove("pull", "img:"+img.ID)
				tmpFile, err := ioutil.TempFile("", "GetV2ImageBlob")
				if err != nil {
					return err
				}

				r, l, err := r.GetV2ImageBlobReader(remoteName, sumType, checksum, nil)
				if err != nil {
					return err
				}
				defer r.Close()
				io.Copy(tmpFile, utils.ProgressReader(r, int(l), out, sf, false, utils.TruncateID(img.ID), "Downloading"))

				out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))

				log.Debugf("Downloaded %s to tempfile %s", img.ID, tmpFile.Name())
				di.tmpFile = tmpFile
				di.length = l
				di.downloaded = true
			}
			di.imgJSON = imgJSON

			return nil
		}

		if parallel {
			downloads[i].err = make(chan error)
			go func(di *downloadInfo) {
				di.err <- downloadFunc(di)
			}(&downloads[i])
		} else {
			err := downloadFunc(&downloads[i])
			if err != nil {
				return false, err
			}
		}
	}

	var layersDownloaded bool
	for i := len(downloads) - 1; i >= 0; i-- {
		d := &downloads[i]
		if d.err != nil {
			err := <-d.err
			if err != nil {
				return false, err
			}
		}
		if d.downloaded {
			// if tmpFile is empty assume download and extracted elsewhere
			defer os.Remove(d.tmpFile.Name())
			defer d.tmpFile.Close()
			d.tmpFile.Seek(0, 0)
			if d.tmpFile != nil {
				err = s.graph.Register(d.img,
					utils.ProgressReader(d.tmpFile, int(d.length), out, sf, false, utils.TruncateID(d.img.ID), "Extracting"))
				if err != nil {
					return false, err
				}

				// FIXME: Pool release here for parallel tag pull (ensures any downloads block until fully extracted)
			}
			out.Write(sf.FormatProgress(utils.TruncateID(d.img.ID), "Pull complete", nil))
			layersDownloaded = true
		} else {
			out.Write(sf.FormatProgress(utils.TruncateID(d.img.ID), "Already exists", nil))
		}

	}

	if err = s.Set(localName, tag, downloads[0].img.ID, true); err != nil {
		return false, err
	}

	return layersDownloaded, nil
}
Example #2
0
func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint string, token []string, sf *utils.StreamFormatter) (bool, error) {
	history, err := r.GetRemoteHistory(imgID, endpoint, token)
	if err != nil {
		return false, err
	}
	out.Write(sf.FormatProgress(utils.TruncateID(imgID), "Pulling dependent layers", nil))
	// FIXME: Try to stream the images?
	// FIXME: Launch the getRemoteImage() in goroutines

	layers_downloaded := false
	for i := len(history) - 1; i >= 0; i-- {
		id := history[i]

		// ensure no two downloads of the same layer happen at the same time
		if c, err := s.poolAdd("pull", "layer:"+id); err != nil {
			log.Debugf("Image (id: %s) pull is already running, skipping: %v", id, err)
			<-c
		}
		defer s.poolRemove("pull", "layer:"+id)

		if !s.graph.Exists(id) {
			out.Write(sf.FormatProgress(utils.TruncateID(id), "Pulling metadata", nil))
			var (
				imgJSON []byte
				imgSize int
				err     error
				img     *image.Image
			)
			retries := 5
			for j := 1; j <= retries; j++ {
				imgJSON, imgSize, err = r.GetRemoteImageJSON(id, endpoint, token)
				if err != nil && j == retries {
					out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
					return layers_downloaded, err
				} else if err != nil {
					time.Sleep(time.Duration(j) * 500 * time.Millisecond)
					continue
				}
				img, err = image.NewImgJSON(imgJSON)
				layers_downloaded = true
				if err != nil && j == retries {
					out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
					return layers_downloaded, fmt.Errorf("Failed to parse json: %s", err)
				} else if err != nil {
					time.Sleep(time.Duration(j) * 500 * time.Millisecond)
					continue
				} else {
					break
				}
			}

			for j := 1; j <= retries; j++ {
				// Get the layer
				status := "Pulling fs layer"
				if j > 1 {
					status = fmt.Sprintf("Pulling fs layer [retries: %d]", j)
				}
				out.Write(sf.FormatProgress(utils.TruncateID(id), status, nil))
				layer, err := r.GetRemoteImageLayer(img.ID, endpoint, token, int64(imgSize))
				if uerr, ok := err.(*url.Error); ok {
					err = uerr.Err
				}
				if terr, ok := err.(net.Error); ok && terr.Timeout() && j < retries {
					time.Sleep(time.Duration(j) * 500 * time.Millisecond)
					continue
				} else if err != nil {
					out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
					return layers_downloaded, err
				}
				layers_downloaded = true
				defer layer.Close()

				err = s.graph.Register(img,
					utils.ProgressReader(layer, imgSize, out, sf, false, utils.TruncateID(id), "Downloading"))
				if terr, ok := err.(net.Error); ok && terr.Timeout() && j < retries {
					time.Sleep(time.Duration(j) * 500 * time.Millisecond)
					continue
				} else if err != nil {
					out.Write(sf.FormatProgress(utils.TruncateID(id), "Error downloading dependent layers", nil))
					return layers_downloaded, err
				} else {
					break
				}
			}
		}
		out.Write(sf.FormatProgress(utils.TruncateID(id), "Download complete", nil))
	}
	return layers_downloaded, nil
}