distribution/push_v2.go
package distribution // import "github.com/docker/docker/distribution"
import (
"context"
"fmt"
"io"
"os"
"runtime"
"sort"
"strings"
"sync"
"github.com/containerd/log"
"github.com/distribution/reference"
"github.com/docker/distribution"
"github.com/docker/distribution/manifest/schema1"
"github.com/docker/distribution/manifest/schema2"
"github.com/docker/distribution/registry/api/errcode"
"github.com/docker/distribution/registry/client"
apitypes "github.com/docker/docker/api/types"
"github.com/docker/docker/distribution/metadata"
"github.com/docker/docker/distribution/xfer"
"github.com/docker/docker/layer"
"github.com/docker/docker/pkg/ioutils"
"github.com/docker/docker/pkg/progress"
"github.com/docker/docker/pkg/stringid"
"github.com/docker/docker/registry"
"github.com/docker/libtrust"
"github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
const (
smallLayerMaximumSize = 100 * (1 << 10) // 100KB
middleLayerMaximumSize = 10 * (1 << 20) // 10MB
)
// newPusher creates a new pusher for pushing to a v2 registry.
// The parameters are passed through to the underlying pusher implementation for
// use during the actual push operation.
func newPusher(ref reference.Named, endpoint registry.APIEndpoint, repoInfo *registry.RepositoryInfo, config *ImagePushConfig) *pusher {
return &pusher{
metadataService: metadata.NewV2MetadataService(config.MetadataStore),
ref: ref,
endpoint: endpoint,
repoInfo: repoInfo,
config: config,
}
}
type pusher struct {
metadataService metadata.V2MetadataService
ref reference.Named
endpoint registry.APIEndpoint
repoInfo *registry.RepositoryInfo
config *ImagePushConfig
repo distribution.Repository
// pushState is state built by the Upload functions.
pushState pushState
}
type pushState struct {
sync.Mutex
// remoteLayers is the set of layers known to exist on the remote side.
// This avoids redundant queries when pushing multiple tags that
// involve the same layers. It is also used to fill in digest and size
// information when building the manifest.
remoteLayers map[layer.DiffID]distribution.Descriptor
hasAuthInfo bool
}
// TODO(tiborvass): have push() take a reference to repository + tag, so that the pusher itself is repository-agnostic.
func (p *pusher) push(ctx context.Context) (err error) {
p.pushState.remoteLayers = make(map[layer.DiffID]distribution.Descriptor)
p.repo, err = newRepository(ctx, p.repoInfo, p.endpoint, p.config.MetaHeaders, p.config.AuthConfig, "push", "pull")
p.pushState.hasAuthInfo = p.config.AuthConfig.RegistryToken != "" || (p.config.AuthConfig.Username != "" && p.config.AuthConfig.Password != "")
if err != nil {
log.G(ctx).Debugf("Error getting v2 registry: %v", err)
return err
}
if err = p.pushRepository(ctx); err != nil {
if continueOnError(err, p.endpoint.Mirror) {
return fallbackError{
err: err,
transportOK: true,
}
}
}
return err
}
func (p *pusher) pushRepository(ctx context.Context) (err error) {
if namedTagged, isNamedTagged := p.ref.(reference.NamedTagged); isNamedTagged {
imageID, err := p.config.ReferenceStore.Get(p.ref)
if err != nil {
return fmt.Errorf("tag does not exist: %s", reference.FamiliarString(p.ref))
}
return p.pushTag(ctx, namedTagged, imageID)
}
if !reference.IsNameOnly(p.ref) {
return errors.New("cannot push a digest reference")
}
// Push all tags
pushed := 0
for _, association := range p.config.ReferenceStore.ReferencesByName(p.ref) {
if namedTagged, isNamedTagged := association.Ref.(reference.NamedTagged); isNamedTagged {
pushed++
if err := p.pushTag(ctx, namedTagged, association.ID); err != nil {
return err
}
}
}
if pushed == 0 {
return fmt.Errorf("no tags to push for %s", reference.FamiliarName(p.repoInfo.Name))
}
return nil
}
func (p *pusher) pushTag(ctx context.Context, ref reference.NamedTagged, id digest.Digest) error {
log.G(ctx).Debugf("Pushing repository: %s", reference.FamiliarString(ref))
imgConfig, err := p.config.ImageStore.Get(ctx, id)
if err != nil {
return fmt.Errorf("could not find image from tag %s: %v", reference.FamiliarString(ref), err)
}
rootfs, err := rootFSFromConfig(imgConfig)
if err != nil {
return fmt.Errorf("unable to get rootfs for image %s: %s", reference.FamiliarString(ref), err)
}
l, err := p.config.LayerStores.Get(rootfs.ChainID())
if err != nil {
return fmt.Errorf("failed to get top layer from image: %v", err)
}
defer l.Release()
hmacKey, err := metadata.ComputeV2MetadataHMACKey(p.config.AuthConfig)
if err != nil {
return fmt.Errorf("failed to compute hmac key of auth config: %v", err)
}
var descriptors []xfer.UploadDescriptor
descriptorTemplate := pushDescriptor{
metadataService: p.metadataService,
hmacKey: hmacKey,
repoInfo: p.repoInfo.Name,
ref: p.ref,
endpoint: p.endpoint,
repo: p.repo,
pushState: &p.pushState,
}
// Loop bounds condition is to avoid pushing the base layer on Windows.
for range rootfs.DiffIDs {
descriptor := descriptorTemplate
descriptor.layer = l
descriptor.checkedDigests = make(map[digest.Digest]struct{})
descriptors = append(descriptors, &descriptor)
l = l.Parent()
}
if err := p.config.UploadManager.Upload(ctx, descriptors, p.config.ProgressOutput); err != nil {
return err
}
// Try schema2 first
builder := schema2.NewManifestBuilder(p.repo.Blobs(ctx), p.config.ConfigMediaType, imgConfig)
manifest, err := manifestFromBuilder(ctx, builder, descriptors)
if err != nil {
return err
}
manSvc, err := p.repo.Manifests(ctx)
if err != nil {
return err
}
putOptions := []distribution.ManifestServiceOption{distribution.WithTag(ref.Tag())}
if _, err = manSvc.Put(ctx, manifest, putOptions...); err != nil {
if runtime.GOOS == "windows" {
log.G(ctx).Warnf("failed to upload schema2 manifest: %v", err)
return err
}
// This is a temporary environment variables used in CI to allow pushing
// manifest v2 schema 1 images to test-registries used for testing *pulling*
// these images.
if os.Getenv("DOCKER_ALLOW_SCHEMA1_PUSH_DONOTUSE") == "" {
if err.Error() == "tag invalid" {
msg := "[DEPRECATED] support for pushing manifest v2 schema1 images has been removed. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/"
log.G(ctx).WithError(err).Error(msg)
return errors.Wrap(err, msg)
}
return err
}
log.G(ctx).Warnf("failed to upload schema2 manifest: %v - falling back to schema1", err)
// Note: this fallback is deprecated, see log messages below
manifestRef, err := reference.WithTag(p.repo.Named(), ref.Tag())
if err != nil {
return err
}
pk, err := libtrust.GenerateECP256PrivateKey()
if err != nil {
return errors.Wrap(err, "unexpected error generating private key")
}
builder = schema1.NewConfigManifestBuilder(p.repo.Blobs(ctx), pk, manifestRef, imgConfig)
manifest, err = manifestFromBuilder(ctx, builder, descriptors)
if err != nil {
return err
}
if _, err = manSvc.Put(ctx, manifest, putOptions...); err != nil {
return err
}
// schema2 failed but schema1 succeeded
msg := fmt.Sprintf("[DEPRECATION NOTICE] support for pushing manifest v2 schema1 images will be removed in an upcoming release. Please contact admins of the %s registry NOW to avoid future disruption. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/", reference.Domain(ref))
log.G(ctx).Warn(msg)
progress.Message(p.config.ProgressOutput, "", msg)
}
var canonicalManifest []byte
switch v := manifest.(type) {
case *schema1.SignedManifest:
canonicalManifest = v.Canonical
case *schema2.DeserializedManifest:
_, canonicalManifest, err = v.Payload()
if err != nil {
return err
}
}
manifestDigest := digest.FromBytes(canonicalManifest)
progress.Messagef(p.config.ProgressOutput, "", "%s: digest: %s size: %d", ref.Tag(), manifestDigest, len(canonicalManifest))
if err := addDigestReference(p.config.ReferenceStore, ref, manifestDigest, id); err != nil {
return err
}
// Signal digest to the trust client so it can sign the
// push, if appropriate.
progress.Aux(p.config.ProgressOutput, apitypes.PushResult{Tag: ref.Tag(), Digest: manifestDigest.String(), Size: len(canonicalManifest)})
return nil
}
func manifestFromBuilder(ctx context.Context, builder distribution.ManifestBuilder, descriptors []xfer.UploadDescriptor) (distribution.Manifest, error) {
// descriptors is in reverse order; iterate backwards to get references
// appended in the right order.
for i := len(descriptors) - 1; i >= 0; i-- {
if err := builder.AppendReference(descriptors[i].(*pushDescriptor)); err != nil {
return nil, err
}
}
return builder.Build(ctx)
}
type pushDescriptor struct {
layer PushLayer
metadataService metadata.V2MetadataService
hmacKey []byte
repoInfo reference.Named
ref reference.Named
endpoint registry.APIEndpoint
repo distribution.Repository
pushState *pushState
remoteDescriptor distribution.Descriptor
// a set of digests whose presence has been checked in a target repository
checkedDigests map[digest.Digest]struct{}
}
func (pd *pushDescriptor) Key() string {
return "v2push:" + pd.ref.Name() + " " + pd.layer.DiffID().String()
}
func (pd *pushDescriptor) ID() string {
return stringid.TruncateID(pd.layer.DiffID().String())
}
func (pd *pushDescriptor) DiffID() layer.DiffID {
return pd.layer.DiffID()
}
func (pd *pushDescriptor) Upload(ctx context.Context, progressOutput progress.Output) (distribution.Descriptor, error) {
// Skip foreign layers unless this registry allows nondistributable artifacts.
if !pd.endpoint.AllowNondistributableArtifacts {
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?
metaData, err := pd.metadataService.GetMetadata(diffID)
if err == nil {
// check for blob existence in the target repository
descriptor, exists, err := pd.layerAlreadyExists(ctx, progressOutput, diffID, true, 1, metaData)
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, metaData)
isUnauthorizedError := false
for _, mc := range candidates {
mountCandidate := mc
log.G(ctx).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.ParseNormalizedNamed(mountCandidate.SourceRepository)
if err != nil {
log.G(ctx).WithError(err).Errorf("failed to parse source repository reference %v", reference.FamiliarString(namedRef))
_ = pd.metadataService.Remove(mountCandidate)
continue
}
// Candidates are always under same domain, create remote reference
// with only path to set mount from with
remoteRef, err := reference.WithName(reference.Path(namedRef))
if err != nil {
log.G(ctx).WithError(err).Errorf("failed to make remote reference out of %q", reference.Path(namedRef))
continue
}
canonicalRef, err := reference.WithDigest(reference.TrimNamed(remoteRef), mountCandidate.Digest)
if err != nil {
log.G(ctx).WithError(err).Error("failed to make canonical reference")
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.remoteLayers[diffID] = err.Descriptor
pd.pushState.Unlock()
// Cache mapping from this layer's DiffID to the blobsum
if err := pd.metadataService.TagAndAdd(diffID, pd.hmacKey, metadata.V2Metadata{
Digest: err.Descriptor.Digest,
SourceRepository: pd.repoInfo.Name(),
}); err != nil {
return distribution.Descriptor{}, xfer.DoNotRetry{Err: err}
}
return err.Descriptor, nil
case errcode.Errors:
for _, e := range err {
switch e := e.(type) {
case errcode.Error:
if e.Code == errcode.ErrorCodeUnauthorized {
// when unauthorized error that indicate user don't has right to push layer to register
log.G(ctx).Debugln("failed to push layer to registry because unauthorized error")
isUnauthorizedError = true
}
default:
}
}
default:
log.G(ctx).Infof("failed to mount layer %s (%s) from %s: %v", diffID, mountCandidate.Digest, mountCandidate.SourceRepository, err)
}
// when error is unauthorizedError and user don't hasAuthInfo that's the case user don't has right to push layer to register
// and he hasn't login either, in this case candidate cache should be removed
if len(mountCandidate.SourceRepository) > 0 &&
!(isUnauthorizedError && !pd.pushState.hasAuthInfo) &&
(metadata.CheckV2MetadataHMAC(&mountCandidate, pd.hmacKey) ||
len(mountCandidate.HMAC) == 0) {
cause := "blob mount failure"
if err != nil {
cause = fmt.Sprintf("an error: %v", err.Error())
}
log.G(ctx).Debugf("removing association between layer %s and %s due to %s", mountCandidate.Digest, mountCandidate.SourceRepository, cause)
_ = pd.metadataService.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), metaData)
if exists || err != nil {
return descriptor, err
}
}
log.G(ctx).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
return pd.uploadUsingSession(ctx, progressOutput, diffID, layerUpload)
}
func (pd *pushDescriptor) SetRemoteDescriptor(descriptor distribution.Descriptor) {
pd.remoteDescriptor = descriptor
}
func (pd *pushDescriptor) Descriptor() distribution.Descriptor {
return pd.remoteDescriptor
}
func (pd *pushDescriptor) uploadUsingSession(
ctx context.Context,
progressOutput progress.Output,
diffID layer.DiffID,
layerUpload distribution.BlobWriter,
) (distribution.Descriptor, error) {
var reader io.ReadCloser
contentReader, err := pd.layer.Open()
if err != nil {
return distribution.Descriptor{}, retryOnError(err)
}
reader = progress.NewProgressReader(ioutils.NewCancelReadCloser(ctx, contentReader), progressOutput, pd.layer.Size(), pd.ID(), "Pushing")
switch m := pd.layer.MediaType(); m {
case schema2.MediaTypeUncompressedLayer:
compressedReader, compressionDone := compress(reader)
defer func(closer io.Closer) {
closer.Close()
<-compressionDone
}(reader)
reader = compressedReader
case schema2.MediaTypeLayer:
default:
reader.Close()
return distribution.Descriptor{}, xfer.DoNotRetry{Err: fmt.Errorf("unsupported layer media type %s", m)}
}
digester := digest.Canonical.Digester()
tee := io.TeeReader(reader, digester.Hash())
nn, err := layerUpload.ReadFrom(tee)
reader.Close()
if err != nil {
return distribution.Descriptor{}, retryOnError(err)
}
pushDigest := digester.Digest()
if _, err := layerUpload.Commit(ctx, distribution.Descriptor{Digest: pushDigest}); err != nil {
return distribution.Descriptor{}, retryOnError(err)
}
log.G(ctx).Debugf("uploaded layer %s (%s), %d bytes", diffID, pushDigest, nn)
progress.Update(progressOutput, pd.ID(), "Pushed")
// Cache mapping from this layer's DiffID to the blobsum
if err := pd.metadataService.TagAndAdd(diffID, pd.hmacKey, metadata.V2Metadata{
Digest: pushDigest,
SourceRepository: pd.repoInfo.Name(),
}); err != nil {
return distribution.Descriptor{}, xfer.DoNotRetry{Err: err}
}
desc := distribution.Descriptor{
Digest: pushDigest,
MediaType: schema2.MediaTypeLayer,
Size: nn,
}
pd.pushState.Lock()
pd.pushState.remoteLayers[diffID] = desc
pd.pushState.Unlock()
return desc, nil
}
// layerAlreadyExists checks if the registry already knows about any of the metadata passed in the "metadata"
// slice. If it finds one that the registry knows about, it returns the known digest and "true". If
// "checkOtherRepositories" is true, stat will be performed also with digests mapped to any other repository
// (not just the target one).
func (pd *pushDescriptor) layerAlreadyExists(
ctx context.Context,
progressOutput progress.Output,
diffID layer.DiffID,
checkOtherRepositories bool,
maxExistenceCheckAttempts int,
v2Metadata []metadata.V2Metadata,
) (desc distribution.Descriptor, exists bool, err error) {
// filter the metadata
candidates := []metadata.V2Metadata{}
for _, meta := range v2Metadata {
if len(meta.SourceRepository) > 0 && !checkOtherRepositories && meta.SourceRepository != pd.repoInfo.Name() {
continue
}
candidates = append(candidates, meta)
}
// sort the candidates by similarity
sortV2MetadataByLikenessAndAge(pd.repoInfo, pd.hmacKey, candidates)
digestToMetadata := make(map[digest.Digest]*metadata.V2Metadata)
// an array of unique blob digests ordered from the best mount candidates to worst
layerDigests := []digest.Digest{}
for i := 0; i < len(candidates); i++ {
if len(layerDigests) >= maxExistenceCheckAttempts {
break
}
meta := &candidates[i]
if _, exists := digestToMetadata[meta.Digest]; exists {
// keep reference just to the first mapping (the best mount candidate)
continue
}
if _, exists := pd.checkedDigests[meta.Digest]; exists {
// existence of this digest has already been tested
continue
}
digestToMetadata[meta.Digest] = meta
layerDigests = append(layerDigests, meta.Digest)
}
attempts:
for _, dgst := range layerDigests {
meta := digestToMetadata[dgst]
log.G(ctx).Debugf("Checking for presence of layer %s (%s) in %s", diffID, dgst, pd.repoInfo.Name())
desc, err = pd.repo.Blobs(ctx).Stat(ctx, dgst)
pd.checkedDigests[meta.Digest] = struct{}{}
switch err {
case nil:
if m, ok := digestToMetadata[desc.Digest]; !ok || m.SourceRepository != pd.repoInfo.Name() || !metadata.CheckV2MetadataHMAC(m, pd.hmacKey) {
// cache mapping from this layer's DiffID to the blobsum
if err := pd.metadataService.TagAndAdd(diffID, pd.hmacKey, metadata.V2Metadata{
Digest: desc.Digest,
SourceRepository: pd.repoInfo.Name(),
}); err != nil {
return distribution.Descriptor{}, false, xfer.DoNotRetry{Err: err}
}
}
desc.MediaType = schema2.MediaTypeLayer
exists = true
break attempts
case distribution.ErrBlobUnknown:
if meta.SourceRepository == pd.repoInfo.Name() {
// remove the mapping to the target repository
pd.metadataService.Remove(*meta)
}
default:
log.G(ctx).WithError(err).Debugf("Failed to check for presence of layer %s (%s) in %s", diffID, dgst, pd.repoInfo.Name())
}
}
if exists {
progress.Update(progressOutput, pd.ID(), "Layer already exists")
pd.pushState.Lock()
pd.pushState.remoteLayers[diffID] = desc
pd.pushState.Unlock()
}
return desc, exists, nil
}
// getMaxMountAndExistenceCheckAttempts returns a maximum number of cross repository mount attempts from
// source repositories of target registry, maximum number of layer existence checks performed on the target
// repository and whether the check shall be done also with digests mapped to different repositories. The
// decision is based on layer size. The smaller the layer, the fewer attempts shall be made because the cost
// of upload does not outweigh a latency.
func getMaxMountAndExistenceCheckAttempts(layer PushLayer) (maxMountAttempts, maxExistenceCheckAttempts int, checkOtherRepositories bool) {
size := layer.Size()
switch {
// big blob
case size > middleLayerMaximumSize:
// 1st attempt to mount the blob few times
// 2nd few existence checks with digests associated to any repository
// then fallback to upload
return 4, 3, true
// middle sized blobs; if we could not get the size, assume we deal with middle sized blob
case size > smallLayerMaximumSize:
// 1st attempt to mount blobs of average size few times
// 2nd try at most 1 existence check if there's an existing mapping to the target repository
// then fallback to upload
return 3, 1, false
// small blobs, do a minimum number of checks
default:
return 1, 1, false
}
}
// getRepositoryMountCandidates returns an array of v2 metadata items belonging to the given registry. The
// array is sorted from youngest to oldest. The resulting array will contain only metadata entries having
// registry part of SourceRepository matching the part of repoInfo.
func getRepositoryMountCandidates(
repoInfo reference.Named,
hmacKey []byte,
max int,
v2Metadata []metadata.V2Metadata,
) []metadata.V2Metadata {
candidates := []metadata.V2Metadata{}
for _, meta := range v2Metadata {
sourceRepo, err := reference.ParseNamed(meta.SourceRepository)
if err != nil || reference.Domain(repoInfo) != reference.Domain(sourceRepo) {
continue
}
// target repository is not a viable candidate
if meta.SourceRepository == repoInfo.Name() {
continue
}
candidates = append(candidates, meta)
}
sortV2MetadataByLikenessAndAge(repoInfo, hmacKey, candidates)
if max >= 0 && len(candidates) > max {
// select the youngest metadata
candidates = candidates[:max]
}
return candidates
}
// byLikeness is a sorting container for v2 metadata candidates for cross repository mount. The
// candidate "a" is preferred over "b":
//
// 1. if it was hashed using the same AuthConfig as the one used to authenticate to target repository and the
// "b" was not
// 2. if a number of its repository path components exactly matching path components of target repository is higher
type byLikeness struct {
arr []metadata.V2Metadata
hmacKey []byte
pathComponents []string
}
func (bla byLikeness) Less(i, j int) bool {
aMacMatch := metadata.CheckV2MetadataHMAC(&bla.arr[i], bla.hmacKey)
bMacMatch := metadata.CheckV2MetadataHMAC(&bla.arr[j], bla.hmacKey)
if aMacMatch != bMacMatch {
return aMacMatch
}
aMatch := numOfMatchingPathComponents(bla.arr[i].SourceRepository, bla.pathComponents)
bMatch := numOfMatchingPathComponents(bla.arr[j].SourceRepository, bla.pathComponents)
return aMatch > bMatch
}
func (bla byLikeness) Swap(i, j int) {
bla.arr[i], bla.arr[j] = bla.arr[j], bla.arr[i]
}
func (bla byLikeness) Len() int { return len(bla.arr) }
func sortV2MetadataByLikenessAndAge(repoInfo reference.Named, hmacKey []byte, marr []metadata.V2Metadata) {
// reverse the metadata array to shift the newest entries to the beginning
for i := 0; i < len(marr)/2; i++ {
marr[i], marr[len(marr)-i-1] = marr[len(marr)-i-1], marr[i]
}
// keep equal entries ordered from the youngest to the oldest
sort.Stable(byLikeness{
arr: marr,
hmacKey: hmacKey,
pathComponents: getPathComponents(repoInfo.Name()),
})
}
// numOfMatchingPathComponents returns a number of path components in "pth" that exactly match "matchComponents".
func numOfMatchingPathComponents(pth string, matchComponents []string) int {
pthComponents := getPathComponents(pth)
i := 0
for ; i < len(pthComponents) && i < len(matchComponents); i++ {
if matchComponents[i] != pthComponents[i] {
return i
}
}
return i
}
func getPathComponents(path string) []string {
return strings.Split(path, "/")
}
func cancelLayerUpload(ctx context.Context, dgst digest.Digest, layerUpload distribution.BlobWriter) {
if layerUpload != nil {
log.G(ctx).Debugf("cancelling upload of blob %s", dgst)
err := layerUpload.Cancel(ctx)
if err != nil {
log.G(ctx).Warnf("failed to cancel upload: %v", err)
}
}
}