mark stargz configuration as experimental

As the stargz compatiblity feature is not production ready
 and reliable enought.

Signed-off-by: Changwei Ge <gechangwei@bytedance.com>

config/config.go

@@ -93,6 +93,10 @@ const (
 	FsDriverFscache string = "fscache"
 )
 
+type Experimental struct {
+	EnableStargz bool `toml:"enable_stargz"`
+}
+
 // Configure how to start and recover nydusd daemons
 type DaemonConfig struct {
 	NydusdPath       string `toml:"nydusd_path"`
@@ -169,7 +173,6 @@ type SnapshotterConfig struct {
 	Address                string `toml:"address"`
 	EnableSystemController bool   `toml:"enable_system_controller"`
 	DaemonMode             string `toml:"daemon_mode"`
-	EnableStargz           bool   `toml:"enable_stargz"`
 	// Clean up all the resources when snapshotter is closed
 	CleanupOnClose bool `toml:"cleanup_on_close"`
 
@@ -180,6 +183,7 @@ type SnapshotterConfig struct {
 	ImageConfig        ImageConfig        `toml:"image"`
 	CacheManagerConfig CacheManagerConfig `toml:"cache_manager"`
 	LoggingConfig      LoggingConfig      `toml:"log"`
+	Experimental       Experimental       `toml:"experimental"`
 }
 
 func LoadSnapshotterConfig(path string) (*SnapshotterConfig, error) {

config/config_test.go

@@ -25,7 +25,7 @@ func TestLoadSnapshotterTOMLConfig(t *testing.T) {
 		Address:                "/run/containerd-nydus/containerd-nydus-grpc.sock",
 		DaemonMode:             "multiple",
 		EnableSystemController: true,
-		EnableStargz:           false,
+		Experimental:           Experimental{EnableStargz: false},
 		CleanupOnClose:         false,
 		DaemonConfig: DaemonConfig{
 			NydusdPath:       "/usr/local/bin/nydusd",

misc/snapshotter/config.toml

@@ -6,8 +6,6 @@ address = "/run/containerd-nydus/containerd-nydus-grpc.sock"
 daemon_mode = "multiple"
 # Snapshotter's debug and trace HTTP server interface
 enable_system_controller = true
-# Whether tp enable stargz support
-enable_stargz = false
 # Whether snapshotter should try to clean up resources when it is closed
 cleanup_on_close = false
 
@@ -75,3 +73,8 @@ cache_dir = ""
 [image]
 public_key_file = ""
 validate_signature = false
+
+# The configuraions for features that are not production ready
+[experimental]
+# Whether tp enable stargz support
+enable_stargz = false

snapshot/snapshot.go

@@ -139,7 +139,7 @@ func NewSnapshotter(ctx context.Context, cfg *config.SnapshotterConfig) (snapsho
 		filesystem.WithNydusImageBinaryPath(cfg.DaemonConfig.NydusdPath),
 		filesystem.WithVerifier(verifier),
 		filesystem.WithRootMountpoint(path.Join(cfg.Root, "mnt")),
-		filesystem.WithEnableStargz(cfg.EnableStargz),
+		filesystem.WithEnableStargz(cfg.Experimental.EnableStargz),
 	}
 
 	cacheConfig := &cfg.CacheManagerConfig