openshift/openshift.go
func (s *openshiftImageSource) GetBlob(ctx context.Context, info types.BlobInfo, cache types.BlobInfoCache) (io.ReadCloser, int64, error) {
	if err := s.ensureImageIsResolved(ctx); err != nil {
		return nil, 0, err
	}
	return s.docker.GetBlob(ctx, info, cache)
}
func (s *openshiftImageSource) GetBlob(ctx context.Context, info types.BlobInfo, cache types.BlobInfoCache) (io.ReadCloser, int64, error) {
	if err := s.ensureImageIsResolved(ctx); err != nil {
		return nil, 0, err
	}
	return s.docker.GetBlob(ctx, info, cache)
}
// GetBlob returns a stream for the specified blob, and the blob’s size (or -1 if unknown).
// The Digest field in BlobInfo is guaranteed to be provided, Size may be -1 and MediaType may be optionally provided.
// May update BlobInfoCache, preferably after it knows for certain that a blob truly exists at a specific location.