mirror of
https://github.com/genuinetools/reg.git
synced 2024-08-21 14:20:23 -04:00
398 lines
11 KiB
Go
398 lines
11 KiB
Go
package storage
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"path"
|
|
"time"
|
|
|
|
"github.com/docker/distribution"
|
|
dcontext "github.com/docker/distribution/context"
|
|
storagedriver "github.com/docker/distribution/registry/storage/driver"
|
|
"github.com/opencontainers/go-digest"
|
|
"github.com/sirupsen/logrus"
|
|
)
|
|
|
|
var (
|
|
errResumableDigestNotAvailable = errors.New("resumable digest not available")
|
|
)
|
|
|
|
const (
|
|
// digestSha256Empty is the canonical sha256 digest of empty data
|
|
digestSha256Empty = "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
|
|
)
|
|
|
|
// blobWriter is used to control the various aspects of resumable
|
|
// blob upload.
|
|
type blobWriter struct {
|
|
ctx context.Context
|
|
blobStore *linkedBlobStore
|
|
|
|
id string
|
|
startedAt time.Time
|
|
digester digest.Digester
|
|
written int64 // track the contiguous write
|
|
|
|
fileWriter storagedriver.FileWriter
|
|
driver storagedriver.StorageDriver
|
|
path string
|
|
|
|
resumableDigestEnabled bool
|
|
committed bool
|
|
}
|
|
|
|
var _ distribution.BlobWriter = &blobWriter{}
|
|
|
|
// ID returns the identifier for this upload.
|
|
func (bw *blobWriter) ID() string {
|
|
return bw.id
|
|
}
|
|
|
|
func (bw *blobWriter) StartedAt() time.Time {
|
|
return bw.startedAt
|
|
}
|
|
|
|
// Commit marks the upload as completed, returning a valid descriptor. The
|
|
// final size and digest are checked against the first descriptor provided.
|
|
func (bw *blobWriter) Commit(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
|
|
dcontext.GetLogger(ctx).Debug("(*blobWriter).Commit")
|
|
|
|
if err := bw.fileWriter.Commit(); err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
bw.Close()
|
|
desc.Size = bw.Size()
|
|
|
|
canonical, err := bw.validateBlob(ctx, desc)
|
|
if err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
if err := bw.moveBlob(ctx, canonical); err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
if err := bw.blobStore.linkBlob(ctx, canonical, desc.Digest); err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
if err := bw.removeResources(ctx); err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
err = bw.blobStore.blobAccessController.SetDescriptor(ctx, canonical.Digest, canonical)
|
|
if err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
bw.committed = true
|
|
return canonical, nil
|
|
}
|
|
|
|
// Cancel the blob upload process, releasing any resources associated with
|
|
// the writer and canceling the operation.
|
|
func (bw *blobWriter) Cancel(ctx context.Context) error {
|
|
dcontext.GetLogger(ctx).Debug("(*blobWriter).Cancel")
|
|
if err := bw.fileWriter.Cancel(); err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := bw.Close(); err != nil {
|
|
dcontext.GetLogger(ctx).Errorf("error closing blobwriter: %s", err)
|
|
}
|
|
|
|
return bw.removeResources(ctx)
|
|
}
|
|
|
|
func (bw *blobWriter) Size() int64 {
|
|
return bw.fileWriter.Size()
|
|
}
|
|
|
|
func (bw *blobWriter) Write(p []byte) (int, error) {
|
|
// Ensure that the current write offset matches how many bytes have been
|
|
// written to the digester. If not, we need to update the digest state to
|
|
// match the current write position.
|
|
if err := bw.resumeDigest(bw.blobStore.ctx); err != nil && err != errResumableDigestNotAvailable {
|
|
return 0, err
|
|
}
|
|
|
|
n, err := io.MultiWriter(bw.fileWriter, bw.digester.Hash()).Write(p)
|
|
bw.written += int64(n)
|
|
|
|
return n, err
|
|
}
|
|
|
|
func (bw *blobWriter) ReadFrom(r io.Reader) (n int64, err error) {
|
|
// Ensure that the current write offset matches how many bytes have been
|
|
// written to the digester. If not, we need to update the digest state to
|
|
// match the current write position.
|
|
if err := bw.resumeDigest(bw.blobStore.ctx); err != nil && err != errResumableDigestNotAvailable {
|
|
return 0, err
|
|
}
|
|
|
|
nn, err := io.Copy(io.MultiWriter(bw.fileWriter, bw.digester.Hash()), r)
|
|
bw.written += nn
|
|
|
|
return nn, err
|
|
}
|
|
|
|
func (bw *blobWriter) Close() error {
|
|
if bw.committed {
|
|
return errors.New("blobwriter close after commit")
|
|
}
|
|
|
|
if err := bw.storeHashState(bw.blobStore.ctx); err != nil && err != errResumableDigestNotAvailable {
|
|
return err
|
|
}
|
|
|
|
return bw.fileWriter.Close()
|
|
}
|
|
|
|
// validateBlob checks the data against the digest, returning an error if it
|
|
// does not match. The canonical descriptor is returned.
|
|
func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
|
|
var (
|
|
verified, fullHash bool
|
|
canonical digest.Digest
|
|
)
|
|
|
|
if desc.Digest == "" {
|
|
// if no descriptors are provided, we have nothing to validate
|
|
// against. We don't really want to support this for the registry.
|
|
return distribution.Descriptor{}, distribution.ErrBlobInvalidDigest{
|
|
Reason: fmt.Errorf("cannot validate against empty digest"),
|
|
}
|
|
}
|
|
|
|
var size int64
|
|
|
|
// Stat the on disk file
|
|
if fi, err := bw.driver.Stat(ctx, bw.path); err != nil {
|
|
switch err := err.(type) {
|
|
case storagedriver.PathNotFoundError:
|
|
// NOTE(stevvooe): We really don't care if the file is
|
|
// not actually present for the reader. We now assume
|
|
// that the desc length is zero.
|
|
desc.Size = 0
|
|
default:
|
|
// Any other error we want propagated up the stack.
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
} else {
|
|
if fi.IsDir() {
|
|
return distribution.Descriptor{}, fmt.Errorf("unexpected directory at upload location %q", bw.path)
|
|
}
|
|
|
|
size = fi.Size()
|
|
}
|
|
|
|
if desc.Size > 0 {
|
|
if desc.Size != size {
|
|
return distribution.Descriptor{}, distribution.ErrBlobInvalidLength
|
|
}
|
|
} else {
|
|
// if provided 0 or negative length, we can assume caller doesn't know or
|
|
// care about length.
|
|
desc.Size = size
|
|
}
|
|
|
|
// TODO(stevvooe): This section is very meandering. Need to be broken down
|
|
// to be a lot more clear.
|
|
|
|
if err := bw.resumeDigest(ctx); err == nil {
|
|
canonical = bw.digester.Digest()
|
|
|
|
if canonical.Algorithm() == desc.Digest.Algorithm() {
|
|
// Common case: client and server prefer the same canonical digest
|
|
// algorithm - currently SHA256.
|
|
verified = desc.Digest == canonical
|
|
} else {
|
|
// The client wants to use a different digest algorithm. They'll just
|
|
// have to be patient and wait for us to download and re-hash the
|
|
// uploaded content using that digest algorithm.
|
|
fullHash = true
|
|
}
|
|
} else if err == errResumableDigestNotAvailable {
|
|
// Not using resumable digests, so we need to hash the entire layer.
|
|
fullHash = true
|
|
} else {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
if fullHash {
|
|
// a fantastic optimization: if the the written data and the size are
|
|
// the same, we don't need to read the data from the backend. This is
|
|
// because we've written the entire file in the lifecycle of the
|
|
// current instance.
|
|
if bw.written == size && digest.Canonical == desc.Digest.Algorithm() {
|
|
canonical = bw.digester.Digest()
|
|
verified = desc.Digest == canonical
|
|
}
|
|
|
|
// If the check based on size fails, we fall back to the slowest of
|
|
// paths. We may be able to make the size-based check a stronger
|
|
// guarantee, so this may be defensive.
|
|
if !verified {
|
|
digester := digest.Canonical.Digester()
|
|
verifier := desc.Digest.Verifier()
|
|
|
|
// Read the file from the backend driver and validate it.
|
|
fr, err := newFileReader(ctx, bw.driver, bw.path, desc.Size)
|
|
if err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
defer fr.Close()
|
|
|
|
tr := io.TeeReader(fr, digester.Hash())
|
|
|
|
if _, err := io.Copy(verifier, tr); err != nil {
|
|
return distribution.Descriptor{}, err
|
|
}
|
|
|
|
canonical = digester.Digest()
|
|
verified = verifier.Verified()
|
|
}
|
|
}
|
|
|
|
if !verified {
|
|
dcontext.GetLoggerWithFields(ctx,
|
|
map[interface{}]interface{}{
|
|
"canonical": canonical,
|
|
"provided": desc.Digest,
|
|
}, "canonical", "provided").
|
|
Errorf("canonical digest does match provided digest")
|
|
return distribution.Descriptor{}, distribution.ErrBlobInvalidDigest{
|
|
Digest: desc.Digest,
|
|
Reason: fmt.Errorf("content does not match digest"),
|
|
}
|
|
}
|
|
|
|
// update desc with canonical hash
|
|
desc.Digest = canonical
|
|
|
|
if desc.MediaType == "" {
|
|
desc.MediaType = "application/octet-stream"
|
|
}
|
|
|
|
return desc, nil
|
|
}
|
|
|
|
// moveBlob moves the data into its final, hash-qualified destination,
|
|
// identified by dgst. The layer should be validated before commencing the
|
|
// move.
|
|
func (bw *blobWriter) moveBlob(ctx context.Context, desc distribution.Descriptor) error {
|
|
blobPath, err := pathFor(blobDataPathSpec{
|
|
digest: desc.Digest,
|
|
})
|
|
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// Check for existence
|
|
if _, err := bw.blobStore.driver.Stat(ctx, blobPath); err != nil {
|
|
switch err := err.(type) {
|
|
case storagedriver.PathNotFoundError:
|
|
break // ensure that it doesn't exist.
|
|
default:
|
|
return err
|
|
}
|
|
} else {
|
|
// If the path exists, we can assume that the content has already
|
|
// been uploaded, since the blob storage is content-addressable.
|
|
// While it may be corrupted, detection of such corruption belongs
|
|
// elsewhere.
|
|
return nil
|
|
}
|
|
|
|
// If no data was received, we may not actually have a file on disk. Check
|
|
// the size here and write a zero-length file to blobPath if this is the
|
|
// case. For the most part, this should only ever happen with zero-length
|
|
// blobs.
|
|
if _, err := bw.blobStore.driver.Stat(ctx, bw.path); err != nil {
|
|
switch err := err.(type) {
|
|
case storagedriver.PathNotFoundError:
|
|
// HACK(stevvooe): This is slightly dangerous: if we verify above,
|
|
// get a hash, then the underlying file is deleted, we risk moving
|
|
// a zero-length blob into a nonzero-length blob location. To
|
|
// prevent this horrid thing, we employ the hack of only allowing
|
|
// to this happen for the digest of an empty blob.
|
|
if desc.Digest == digestSha256Empty {
|
|
return bw.blobStore.driver.PutContent(ctx, blobPath, []byte{})
|
|
}
|
|
|
|
// We let this fail during the move below.
|
|
logrus.
|
|
WithField("upload.id", bw.ID()).
|
|
WithField("digest", desc.Digest).Warnf("attempted to move zero-length content with non-zero digest")
|
|
default:
|
|
return err // unrelated error
|
|
}
|
|
}
|
|
|
|
// TODO(stevvooe): We should also write the mediatype when executing this move.
|
|
|
|
return bw.blobStore.driver.Move(ctx, bw.path, blobPath)
|
|
}
|
|
|
|
// removeResources should clean up all resources associated with the upload
|
|
// instance. An error will be returned if the clean up cannot proceed. If the
|
|
// resources are already not present, no error will be returned.
|
|
func (bw *blobWriter) removeResources(ctx context.Context) error {
|
|
dataPath, err := pathFor(uploadDataPathSpec{
|
|
name: bw.blobStore.repository.Named().Name(),
|
|
id: bw.id,
|
|
})
|
|
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// Resolve and delete the containing directory, which should include any
|
|
// upload related files.
|
|
dirPath := path.Dir(dataPath)
|
|
if err := bw.blobStore.driver.Delete(ctx, dirPath); err != nil {
|
|
switch err := err.(type) {
|
|
case storagedriver.PathNotFoundError:
|
|
break // already gone!
|
|
default:
|
|
// This should be uncommon enough such that returning an error
|
|
// should be okay. At this point, the upload should be mostly
|
|
// complete, but perhaps the backend became unaccessible.
|
|
dcontext.GetLogger(ctx).Errorf("unable to delete layer upload resources %q: %v", dirPath, err)
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (bw *blobWriter) Reader() (io.ReadCloser, error) {
|
|
// todo(richardscothern): Change to exponential backoff, i=0.5, e=2, n=4
|
|
try := 1
|
|
for try <= 5 {
|
|
_, err := bw.driver.Stat(bw.ctx, bw.path)
|
|
if err == nil {
|
|
break
|
|
}
|
|
switch err.(type) {
|
|
case storagedriver.PathNotFoundError:
|
|
dcontext.GetLogger(bw.ctx).Debugf("Nothing found on try %d, sleeping...", try)
|
|
time.Sleep(1 * time.Second)
|
|
try++
|
|
default:
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
readCloser, err := bw.driver.Reader(bw.ctx, bw.path, 0)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return readCloser, nil
|
|
}
|