示例#1
0
文件: push_v2.go 项目: mYmNeo/docker
func (pd *v2PushDescriptor) Upload(ctx context.Context, progressOutput progress.Output) (distribution.Descriptor, error) {
	if fs, ok := pd.layer.(distribution.Describable); ok {
		if d := fs.Descriptor(); len(d.URLs) > 0 {
			progress.Update(progressOutput, pd.ID(), "Skipped foreign layer")
			return d, nil
		}
	}

	diffID := pd.DiffID()

	pd.pushState.Lock()
	if descriptor, ok := pd.pushState.remoteLayers[diffID]; ok {
		// it is already known that the push is not needed and
		// therefore doing a stat is unnecessary
		pd.pushState.Unlock()
		progress.Update(progressOutput, pd.ID(), "Layer already exists")
		return descriptor, nil
	}
	pd.pushState.Unlock()

	maxMountAttempts, maxExistenceChecks, checkOtherRepositories := getMaxMountAndExistenceCheckAttempts(pd.layer)

	// Do we have any metadata associated with this layer's DiffID?
	v2Metadata, err := pd.v2MetadataService.GetMetadata(diffID)
	if err == nil {
		// check for blob existence in the target repository if we have a mapping with it
		descriptor, exists, err := pd.layerAlreadyExists(ctx, progressOutput, diffID, false, 1, v2Metadata)
		if exists || err != nil {
			return descriptor, err
		}
	}

	// if digest was empty or not saved, or if blob does not exist on the remote repository,
	// then push the blob.
	bs := pd.repo.Blobs(ctx)

	var layerUpload distribution.BlobWriter

	// Attempt to find another repository in the same registry to mount the layer from to avoid an unnecessary upload
	candidates := getRepositoryMountCandidates(pd.repoInfo, pd.hmacKey, maxMountAttempts, v2Metadata)
	for _, mountCandidate := range candidates {
		logrus.Debugf("attempting to mount layer %s (%s) from %s", diffID, mountCandidate.Digest, mountCandidate.SourceRepository)
		createOpts := []distribution.BlobCreateOption{}

		if len(mountCandidate.SourceRepository) > 0 {
			namedRef, err := reference.WithName(mountCandidate.SourceRepository)
			if err != nil {
				logrus.Errorf("failed to parse source repository reference %v: %v", namedRef.String(), err)
				pd.v2MetadataService.Remove(mountCandidate)
				continue
			}

			// TODO (brianbland): We need to construct a reference where the Name is
			// only the full remote name, so clean this up when distribution has a
			// richer reference package
			remoteRef, err := distreference.WithName(namedRef.RemoteName())
			if err != nil {
				logrus.Errorf("failed to make remote reference out of %q: %v", namedRef.RemoteName(), namedRef.RemoteName())
				continue
			}

			canonicalRef, err := distreference.WithDigest(distreference.TrimNamed(remoteRef), mountCandidate.Digest)
			if err != nil {
				logrus.Errorf("failed to make canonical reference: %v", err)
				continue
			}

			createOpts = append(createOpts, client.WithMountFrom(canonicalRef))
		}

		// send the layer
		lu, err := bs.Create(ctx, createOpts...)
		switch err := err.(type) {
		case nil:
			// noop
		case distribution.ErrBlobMounted:
			progress.Updatef(progressOutput, pd.ID(), "Mounted from %s", err.From.Name())

			err.Descriptor.MediaType = schema2.MediaTypeLayer

			pd.pushState.Lock()
			pd.pushState.confirmedV2 = true
			pd.pushState.remoteLayers[diffID] = err.Descriptor
			pd.pushState.Unlock()

			// Cache mapping from this layer's DiffID to the blobsum
			if err := pd.v2MetadataService.TagAndAdd(diffID, pd.hmacKey, metadata.V2Metadata{
				Digest:           err.Descriptor.Digest,
				SourceRepository: pd.repoInfo.FullName(),
			}); err != nil {
				return distribution.Descriptor{}, xfer.DoNotRetry{Err: err}
			}
			return err.Descriptor, nil
		default:
			logrus.Infof("failed to mount layer %s (%s) from %s: %v", diffID, mountCandidate.Digest, mountCandidate.SourceRepository, err)
		}

		if len(mountCandidate.SourceRepository) > 0 &&
			(metadata.CheckV2MetadataHMAC(&mountCandidate, pd.hmacKey) ||
				len(mountCandidate.HMAC) == 0) {
			cause := "blob mount failure"
			if err != nil {
				cause = fmt.Sprintf("an error: %v", err.Error())
			}
			logrus.Debugf("removing association between layer %s and %s due to %s", mountCandidate.Digest, mountCandidate.SourceRepository, cause)
			pd.v2MetadataService.Remove(mountCandidate)
		}

		if lu != nil {
			// cancel previous upload
			cancelLayerUpload(ctx, mountCandidate.Digest, layerUpload)
			layerUpload = lu
		}
	}

	if maxExistenceChecks-len(pd.checkedDigests) > 0 {
		// do additional layer existence checks with other known digests if any
		descriptor, exists, err := pd.layerAlreadyExists(ctx, progressOutput, diffID, checkOtherRepositories, maxExistenceChecks-len(pd.checkedDigests), v2Metadata)
		if exists || err != nil {
			return descriptor, err
		}
	}

	logrus.Debugf("Pushing layer: %s", diffID)
	if layerUpload == nil {
		layerUpload, err = bs.Create(ctx)
		if err != nil {
			return distribution.Descriptor{}, retryOnError(err)
		}
	}
	defer layerUpload.Close()

	// upload the blob
	desc, err := pd.uploadUsingSession(ctx, progressOutput, diffID, layerUpload)
	if err != nil {
		return desc, err
	}

	return desc, nil
}
示例#2
0
// TrimNamed removes any tag or digest from the named reference
func TrimNamed(ref Named) Named {
	return &namedRef{distreference.TrimNamed(ref)}
}