cleanup orphan remote snapshots after restart

cmd/containerd-stargz-grpc/main.go

@@ -197,6 +197,11 @@ func main() {
 		if !managerNewlyStarted {
 			flags = append(flags, snbase.NoRestore)
 		}
+		imageServicePath := config.ImageServicePath
+		if imageServicePath == "" {
+			imageServicePath = defaultImageServiceAddress
+		}
+		flags = append(flags, snbase.CleanupOrphanRemoteSnapshotsOnStartup(imageServicePath))
 		rs, err = snbase.NewSnapshotter(ctx, filepath.Join(*rootDir, "snapshotter"), fs, flags...)
 		if err != nil {
 			log.G(ctx).WithError(err).Fatalf("failed to configure snapshotter")
@@ -253,7 +258,11 @@ func main() {
 			log.G(ctx).WithError(err).Fatalf("failed to configure fs config")
 		}
 
-		rs, err = service.NewStargzSnapshotterService(ctx, *rootDir, &config.Config,
+		serviceConfig := config.Config
+		if serviceConfig.ImageServicePath == "" {
+			serviceConfig.ImageServicePath = defaultImageServiceAddress
+		}
+		rs, err = service.NewStargzSnapshotterService(ctx, *rootDir, &serviceConfig,
 			service.WithCredsFuncs(credsFuncs...), service.WithFilesystemOptions(fsOpts...))
 		if err != nil {
 			log.G(ctx).WithError(err).Fatalf("failed to configure snapshotter")

fs/fs.go

@@ -462,6 +462,10 @@ func (fs *filesystem) Unmount(ctx context.Context, mountpoint string) error {
 	return nil
 }
 
+func (fs *filesystem) Cleanup(ctx context.Context) error {
+	return fs.resolver.Cleanup(ctx)
+}
+
 func unmount(target string, flags int) error {
 	for {
 		if err := unix.Unmount(target, flags); err != unix.EINTR {

fs/layer/layer.go

@@ -25,6 +25,7 @@ package layer
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -196,6 +197,20 @@ func NewResolver(root string, backgroundTaskManager *task.BackgroundTaskManager,
 	}, nil
 }
 
+func (r *Resolver) Cleanup(ctx context.Context) error {
+	var errs []error
+	for _, dir := range []string{
+		filepath.Join(r.rootDir, "fscache"),
+		filepath.Join(r.rootDir, "httpcache"),
+	} {
+		if err := os.RemoveAll(dir); err != nil {
+			log.G(ctx).WithError(err).WithField("dir", dir).Warn("failed to cleanup cache directory")
+			errs = append(errs, err)
+		}
+	}
+	return errors.Join(errs...)
+}
+
 func newCache(root string, cacheType string, cfg config.Config) (cache.BlobCache, error) {
 	if cacheType == memoryCacheType {
 		return cache.NewMemoryCache(), nil

service/service.go

@@ -78,6 +78,9 @@ func NewStargzSnapshotterService(ctx context.Context, root string, config *Confi
 	if config.AllowInvalidMountsOnRestart {
 		snOpts = append(snOpts, snapshot.AllowInvalidMountsOnRestart)
 	}
+	if config.ImageServicePath != "" {
+		snOpts = append(snOpts, snapshot.CleanupOrphanRemoteSnapshotsOnStartup(config.ImageServicePath))
+	}
 
 	snapshotter, err = snapshot.NewSnapshotter(ctx, snapshotterRoot(root), fs, snOpts...)
 	if err != nil {