Export storage.CreateOptions in top-level package

Let the options for `BlobStore.Create()` be modified in middleware
wrappers.

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

blobs.go

@@ -192,6 +192,15 @@ type BlobCreateOption interface {
 	Apply(interface{}) error
 }
 
+// CreateOptions is a collection of blob creation modifiers relevant to general
+// blob storage intended to be configured by the BlobCreateOption.Apply method.
+type CreateOptions struct {
+	Mount struct {
+		ShouldMount bool
+		From        reference.Canonical
+	}
+}
+
 // BlobWriter provides a handle for inserting data into a blob store.
 // Instances should be obtained from BlobWriteService.Writer and
 // BlobWriteService.Resume. If supported by the store, a writer can be

registry/client/repository.go

@@ -672,15 +672,6 @@ func (bs *blobs) Put(ctx context.Context, mediaType string, p []byte) (distribut
 	return writer.Commit(ctx, desc)
 }
 
-// createOptions is a collection of blob creation modifiers relevant to general
-// blob storage intended to be configured by the BlobCreateOption.Apply method.
-type createOptions struct {
-	Mount struct {
-		ShouldMount bool
-		From        reference.Canonical
-	}
-}
-
 type optionFunc func(interface{}) error
 
 func (f optionFunc) Apply(v interface{}) error {
@@ -691,7 +682,7 @@ func (f optionFunc) Apply(v interface{}) error {
 // mounted from the given canonical reference.
 func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
 	return optionFunc(func(v interface{}) error {
-		opts, ok := v.(*createOptions)
+		opts, ok := v.(*distribution.CreateOptions)
 		if !ok {
 			return fmt.Errorf("unexpected options type: %T", v)
 		}
@@ -704,7 +695,7 @@ func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
 }
 
 func (bs *blobs) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
-	var opts createOptions
+	var opts distribution.CreateOptions
 
 	for _, option := range options {
 		err := option.Apply(&opts)

registry/storage/linkedblobstore.go

@@ -101,15 +101,6 @@ func (lbs *linkedBlobStore) Put(ctx context.Context, mediaType string, p []byte)
 	return desc, lbs.linkBlob(ctx, desc)
 }
 
-// createOptions is a collection of blob creation modifiers relevant to general
-// blob storage intended to be configured by the BlobCreateOption.Apply method.
-type createOptions struct {
-	Mount struct {
-		ShouldMount bool
-		From        reference.Canonical
-	}
-}
-
 type optionFunc func(interface{}) error
 
 func (f optionFunc) Apply(v interface{}) error {
@@ -120,7 +111,7 @@ func (f optionFunc) Apply(v interface{}) error {
 // mounted from the given canonical reference.
 func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
 	return optionFunc(func(v interface{}) error {
-		opts, ok := v.(*createOptions)
+		opts, ok := v.(*distribution.CreateOptions)
 		if !ok {
 			return fmt.Errorf("unexpected options type: %T", v)
 		}
@@ -136,7 +127,7 @@ func WithMountFrom(ref reference.Canonical) distribution.BlobCreateOption {
 func (lbs *linkedBlobStore) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
 	context.GetLogger(ctx).Debug("(*linkedBlobStore).Writer")
 
-	var opts createOptions
+	var opts distribution.CreateOptions
 
 	for _, option := range options {
 		err := option.Apply(&opts)

registry/storage/linkedblobstore_test.go

@@ -0,0 +1,78 @@
+package storage
+
+import (
+	"io"
+	"testing"
+
+	"github.com/docker/distribution"
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/digest"
+
+	"github.com/docker/distribution/reference"
+	"github.com/docker/distribution/testutil"
+)
+
+func TestLinkedBlobStoreCreateWithMountFrom(t *testing.T) {
+	fooRepoName, _ := reference.ParseNamed("nm/foo")
+	fooEnv := newManifestStoreTestEnv(t, fooRepoName, "thetag")
+	ctx := context.Background()
+
+	// Build up some test layers and add them to the manifest, saving the
+	// readseekers for upload later.
+	testLayers := map[digest.Digest]io.ReadSeeker{}
+	for i := 0; i < 2; i++ {
+		rs, ds, err := testutil.CreateRandomTarFile()
+		if err != nil {
+			t.Fatalf("unexpected error generating test layer file")
+		}
+		dgst := digest.Digest(ds)
+
+		testLayers[digest.Digest(dgst)] = rs
+	}
+
+	// upload the layers to foo/bar
+	for dgst, rs := range testLayers {
+		wr, err := fooEnv.repository.Blobs(fooEnv.ctx).Create(fooEnv.ctx)
+		if err != nil {
+			t.Fatalf("unexpected error creating test upload: %v", err)
+		}
+
+		if _, err := io.Copy(wr, rs); err != nil {
+			t.Fatalf("unexpected error copying to upload: %v", err)
+		}
+
+		if _, err := wr.Commit(fooEnv.ctx, distribution.Descriptor{Digest: dgst}); err != nil {
+			t.Fatalf("unexpected error finishing upload: %v", err)
+		}
+	}
+
+	// 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)
+	}
+
+	// cross-repo mount the test layers into a nm/bar
+	for dgst := range testLayers {
+		fooCanonical, _ := reference.WithDigest(fooRepoName, dgst)
+		option := WithMountFrom(fooCanonical)
+		// ensure we can instrospect it
+		createOpts := distribution.CreateOptions{}
+		if err := option.Apply(&createOpts); err != nil {
+			t.Fatalf("failed to apply MountFrom option: %v", err)
+		}
+		if !createOpts.Mount.ShouldMount || createOpts.Mount.From.String() != fooCanonical.String() {
+			t.Fatalf("unexpected create options: %#+v", createOpts.Mount)
+		}
+
+		_, err := barRepo.Blobs(ctx).Create(ctx, WithMountFrom(fooCanonical))
+		if err == nil {
+			t.Fatalf("unexpected non-error while mounting from %q: %v", fooRepoName.String(), err)
+		}
+		if _, ok := err.(distribution.ErrBlobMounted); !ok {
+			t.Fatalf("expected ErrMountFrom error, not %T: %v", err, err)
+		}
+	}
+}