Provide stat descriptor for Create method during cross-repo mount (#1857)

* Allow precomputed stats on cross-mounted blobs

Signed-off-by: Michal Minář <miminar@redhat.com>

* Extended cross-repo mount tests

Signed-off-by: Michal Minář <miminar@redhat.com>
This commit is contained in:
Michal Minář 2016-08-02 04:07:11 +02:00 committed by Richard Scothern
parent 87917f3052
commit 7365003236
3 changed files with 159 additions and 10 deletions

View file

@ -198,6 +198,9 @@ type CreateOptions struct {
Mount struct {
ShouldMount bool
From reference.Canonical
// Stat allows to pass precalculated descriptor to link and return.
// Blob access check will be skipped if set.
Stat *Descriptor
}
}

View file

@ -137,7 +137,7 @@ func (lbs *linkedBlobStore) Create(ctx context.Context, options ...distribution.
}
if opts.Mount.ShouldMount {
desc, err := lbs.mount(ctx, opts.Mount.From, opts.Mount.From.Digest())
desc, err := lbs.mount(ctx, opts.Mount.From, opts.Mount.From.Digest(), opts.Mount.Stat)
if err == nil {
// Mount successful, no need to initiate an upload session
return nil, distribution.ErrBlobMounted{From: opts.Mount.From, Descriptor: desc}
@ -280,15 +280,22 @@ func (lbs *linkedBlobStore) Enumerate(ctx context.Context, ingestor func(digest.
return nil
}
func (lbs *linkedBlobStore) mount(ctx context.Context, sourceRepo reference.Named, dgst digest.Digest) (distribution.Descriptor, error) {
func (lbs *linkedBlobStore) mount(ctx context.Context, sourceRepo reference.Named, dgst digest.Digest, sourceStat *distribution.Descriptor) (distribution.Descriptor, error) {
var stat distribution.Descriptor
if sourceStat == nil {
// look up the blob info from the sourceRepo if not already provided
repo, err := lbs.registry.Repository(ctx, sourceRepo)
if err != nil {
return distribution.Descriptor{}, err
}
stat, err := repo.Blobs(ctx).Stat(ctx, dgst)
stat, err = repo.Blobs(ctx).Stat(ctx, dgst)
if err != nil {
return distribution.Descriptor{}, err
}
} else {
// use the provided blob info
stat = *sourceStat
}
desc := distribution.Descriptor{
Size: stat.Size,

View file

@ -1,7 +1,10 @@
package storage
import (
"fmt"
"io"
"reflect"
"strconv"
"testing"
"github.com/docker/distribution"
@ -16,6 +19,10 @@ func TestLinkedBlobStoreCreateWithMountFrom(t *testing.T) {
fooRepoName, _ := reference.ParseNamed("nm/foo")
fooEnv := newManifestStoreTestEnv(t, fooRepoName, "thetag")
ctx := context.Background()
stats, err := mockRegistry(t, fooEnv.registry)
if err != nil {
t.Fatal(err)
}
// Build up some test layers and add them to the manifest, saving the
// readseekers for upload later.
@ -48,7 +55,6 @@ func TestLinkedBlobStoreCreateWithMountFrom(t *testing.T) {
// create another repository nm/bar
barRepoName, _ := reference.ParseNamed("nm/bar")
barRepo, err := fooEnv.registry.Repository(ctx, barRepoName)
if err != nil {
t.Fatalf("unexpected error getting repo: %v", err)
@ -75,4 +81,137 @@ func TestLinkedBlobStoreCreateWithMountFrom(t *testing.T) {
t.Fatalf("expected ErrMountFrom error, not %T: %v", err, err)
}
}
for dgst := range testLayers {
fooCanonical, _ := reference.WithDigest(fooRepoName, dgst)
count, exists := stats[fooCanonical.String()]
if !exists {
t.Errorf("expected entry %q not found among handled stat calls", fooCanonical.String())
} else if count != 1 {
t.Errorf("expected exactly one stat call for entry %q, not %d", fooCanonical.String(), count)
}
}
clearStats(stats)
// create yet another repository nm/baz
bazRepoName, _ := reference.ParseNamed("nm/baz")
bazRepo, err := fooEnv.registry.Repository(ctx, bazRepoName)
if err != nil {
t.Fatalf("unexpected error getting repo: %v", err)
}
// cross-repo mount them into a nm/baz and provide a prepopulated blob descriptor
for dgst := range testLayers {
fooCanonical, _ := reference.WithDigest(fooRepoName, dgst)
size, err := strconv.ParseInt("0x"+dgst.Hex()[:8], 0, 64)
if err != nil {
t.Fatal(err)
}
prepolutatedDescriptor := distribution.Descriptor{
Digest: dgst,
Size: size,
MediaType: "application/octet-stream",
}
_, err = bazRepo.Blobs(ctx).Create(ctx, WithMountFrom(fooCanonical), &statCrossMountCreateOption{
desc: prepolutatedDescriptor,
})
blobMounted, ok := err.(distribution.ErrBlobMounted)
if !ok {
t.Errorf("expected ErrMountFrom error, not %T: %v", err, err)
continue
}
if !reflect.DeepEqual(blobMounted.Descriptor, prepolutatedDescriptor) {
t.Errorf("unexpected descriptor: %#+v != %#+v", blobMounted.Descriptor, prepolutatedDescriptor)
}
}
// this time no stat calls will be made
if len(stats) != 0 {
t.Errorf("unexpected number of stats made: %d != %d", len(stats), len(testLayers))
}
}
func clearStats(stats map[string]int) {
for k := range stats {
delete(stats, k)
}
}
// mockRegistry sets a mock blob descriptor service factory that overrides
// statter's Stat method to note each attempt to stat a blob in any repository.
// Returned stats map contains canonical references to blobs with a number of
// attempts.
func mockRegistry(t *testing.T, nm distribution.Namespace) (map[string]int, error) {
registry, ok := nm.(*registry)
if !ok {
return nil, fmt.Errorf("not an expected type of registry: %T", nm)
}
stats := make(map[string]int)
registry.blobDescriptorServiceFactory = &mockBlobDescriptorServiceFactory{
t: t,
stats: stats,
}
return stats, nil
}
type mockBlobDescriptorServiceFactory struct {
t *testing.T
stats map[string]int
}
func (f *mockBlobDescriptorServiceFactory) BlobAccessController(svc distribution.BlobDescriptorService) distribution.BlobDescriptorService {
return &mockBlobDescriptorService{
BlobDescriptorService: svc,
t: f.t,
stats: f.stats,
}
}
type mockBlobDescriptorService struct {
distribution.BlobDescriptorService
t *testing.T
stats map[string]int
}
var _ distribution.BlobDescriptorService = &mockBlobDescriptorService{}
func (bs *mockBlobDescriptorService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
statter, ok := bs.BlobDescriptorService.(*linkedBlobStatter)
if !ok {
return distribution.Descriptor{}, fmt.Errorf("unexpected blob descriptor service: %T", bs.BlobDescriptorService)
}
name := statter.repository.Named()
canonical, err := reference.WithDigest(name, dgst)
if err != nil {
return distribution.Descriptor{}, fmt.Errorf("failed to make canonical reference: %v", err)
}
bs.stats[canonical.String()]++
bs.t.Logf("calling Stat on %s", canonical.String())
return bs.BlobDescriptorService.Stat(ctx, dgst)
}
// statCrossMountCreateOptions ensures the expected options type is passed, and optionally pre-fills the cross-mount stat info
type statCrossMountCreateOption struct {
desc distribution.Descriptor
}
var _ distribution.BlobCreateOption = statCrossMountCreateOption{}
func (f statCrossMountCreateOption) Apply(v interface{}) error {
opts, ok := v.(*distribution.CreateOptions)
if !ok {
return fmt.Errorf("Unexpected create options: %#v", v)
}
if !opts.Mount.ShouldMount {
return nil
}
opts.Mount.Stat = &f.desc
return nil
}