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
}
// TrimNamed removes any tag or digest from the named reference
func TrimNamed(ref Named) Named {
return &namedRef{distreference.TrimNamed(ref)}
}