Transfer Service: enable remote snapshotters

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

core/transfer/local/pull.go

@@ -31,6 +31,7 @@ import (
 	"github.com/containerd/containerd/v2/core/transfer"
 	"github.com/containerd/containerd/v2/core/unpack"
 	"github.com/containerd/containerd/v2/defaults"
+	snpkg "github.com/containerd/containerd/v2/pkg/snapshotters"
 )
 
 func (ts *localTransferService) pull(ctx context.Context, ir transfer.ImageFetcher, is transfer.ImageStorer, tops *transfer.Config) error {
@@ -183,10 +184,14 @@ func (ts *localTransferService) pull(ctx context.Context, ir transfer.ImageFetch
 		unpacks := iu.UnpackPlatforms()
 		if len(unpacks) > 0 {
 			uopts := []unpack.UnpackerOpt{}
+			enableRemoteSnapshotAnnotations := false
 			// Only unpack if requested unpackconfig matches default/supported unpackconfigs
 			for _, u := range unpacks {
 				matched, mu := getSupportedPlatform(u, ts.config.UnpackPlatforms)
 				if matched {
+					if v, ok := mu.SnapshotterExports["enable_remote_snapshot_annotations"]; ok && v == "true" {
+						enableRemoteSnapshotAnnotations = true
+					}
 					uopts = append(uopts, unpack.WithUnpackPlatform(mu))
 				}
 			}
@@ -199,6 +204,10 @@ func (ts *localTransferService) pull(ctx context.Context, ir transfer.ImageFetch
 				uopts = append(uopts, unpack.WithDuplicationSuppressor(ts.config.DuplicationSuppressor))
 			}
 
+			if enableRemoteSnapshotAnnotations {
+				handler = snpkg.AppendInfoHandlerWrapper(name)(handler)
+			}
+
 			unpacker, err = unpack.NewUnpacker(ctx, ts.content, uopts...)
 			if err != nil {
 				return fmt.Errorf("unable to initialize unpacker: %w", err)