Respect default snapshotter label

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>

client.go

@@ -332,7 +332,6 @@ func defaultRemoteContext() *RemoteContext {
 		Resolver: docker.NewResolver(docker.ResolverOptions{
 			Client: http.DefaultClient,
 		}),
-		Snapshotter: DefaultSnapshotter,
 	}
 }
 
@@ -672,7 +671,13 @@ func (c *Client) Version(ctx context.Context) (Version, error) {
 	}, nil
 }
 
-func (c *Client) getSnapshotter(name string) (snapshots.Snapshotter, error) {
+func (c *Client) getSnapshotter(ctx context.Context, name string) (snapshots.Snapshotter, error) {
+	if name == "" {
+		if err := c.GetLabel(ctx, defaults.DefaultSnapshotterNSLabel, &name, DefaultSnapshotter); err != nil {
+			return nil, err
+		}
+	}
+
 	s := c.SnapshotService(name)
 	if s == nil {
 		return nil, errors.Wrapf(errdefs.ErrNotFound, "snapshotter %s was not found", name)

cmd/ctr/commands/commands.go

@@ -24,7 +24,6 @@ import (
 	"runtime"
 	"strings"
 
-	"github.com/containerd/containerd"
 	"github.com/urfave/cli"
 )
 
@@ -34,7 +33,6 @@ var (
 		cli.StringFlag{
 			Name:   "snapshotter",
 			Usage:  "snapshotter name. Empty value stands for the default value.",
-			Value:  containerd.DefaultSnapshotter,
 			EnvVar: "CONTAINERD_SNAPSHOTTER",
 		},
 	}

container.go

@@ -233,7 +233,7 @@ func (c *container) NewTask(ctx context.Context, ioCreate cio.Creator, opts ...N
 		}
 
 		// get the rootfs from the snapshotter and add it to the request
-		s, err := c.client.getSnapshotter(r.Snapshotter)
+		s, err := c.client.getSnapshotter(ctx, r.Snapshotter)
 		if err != nil {
 			return nil, err
 		}

container_opts.go

@@ -20,9 +20,7 @@ import (
 	"context"
 
 	"github.com/containerd/containerd/containers"
-	"github.com/containerd/containerd/defaults"
 	"github.com/containerd/containerd/errdefs"
-	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/oci"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/snapshots"
@@ -118,9 +116,8 @@ func WithSnapshotter(name string) NewContainerOpts {
 // WithSnapshot uses an existing root filesystem for the container
 func WithSnapshot(id string) NewContainerOpts {
 	return func(ctx context.Context, client *Client, c *containers.Container) error {
-		setSnapshotterIfEmpty(ctx, client, c)
 		// check that the snapshot exists, if not, fail on creation
-		s, err := client.getSnapshotter(c.Snapshotter)
+		s, err := client.getSnapshotter(ctx, c.Snapshotter)
 		if err != nil {
 			return err
 		}
@@ -140,9 +137,9 @@ func WithNewSnapshot(id string, i Image, opts ...snapshots.Opt) NewContainerOpts
 		if err != nil {
 			return err
 		}
-		setSnapshotterIfEmpty(ctx, client, c)
+
 		parent := identity.ChainID(diffIDs).String()
-		s, err := client.getSnapshotter(c.Snapshotter)
+		s, err := client.getSnapshotter(ctx, c.Snapshotter)
 		if err != nil {
 			return err
 		}
@@ -161,7 +158,7 @@ func WithSnapshotCleanup(ctx context.Context, client *Client, c containers.Conta
 		if c.Snapshotter == "" {
 			return errors.Wrapf(errdefs.ErrInvalidArgument, "container.Snapshotter must be set to cleanup rootfs snapshot")
 		}
-		s, err := client.getSnapshotter(c.Snapshotter)
+		s, err := client.getSnapshotter(ctx, c.Snapshotter)
 		if err != nil {
 			return err
 		}
@@ -178,9 +175,9 @@ func WithNewSnapshotView(id string, i Image, opts ...snapshots.Opt) NewContainer
 		if err != nil {
 			return err
 		}
-		setSnapshotterIfEmpty(ctx, client, c)
+
 		parent := identity.ChainID(diffIDs).String()
-		s, err := client.getSnapshotter(c.Snapshotter)
+		s, err := client.getSnapshotter(ctx, c.Snapshotter)
 		if err != nil {
 			return err
 		}
@@ -193,21 +190,6 @@ func WithNewSnapshotView(id string, i Image, opts ...snapshots.Opt) NewContainer
 	}
 }
 
-func setSnapshotterIfEmpty(ctx context.Context, client *Client, c *containers.Container) {
-	if c.Snapshotter == "" {
-		defaultSnapshotter := DefaultSnapshotter
-		namespaceService := client.NamespaceService()
-		if ns, err := namespaces.NamespaceRequired(ctx); err == nil {
-			if labels, err := namespaceService.Labels(ctx, ns); err == nil {
-				if snapshotLabel, ok := labels[defaults.DefaultSnapshotterNSLabel]; ok {
-					defaultSnapshotter = snapshotLabel
-				}
-			}
-		}
-		c.Snapshotter = defaultSnapshotter
-	}
-}
-
 // WithContainerExtension appends extension data to the container object.
 // Use this to decorate the container object with additional data for the client
 // integration.

container_opts_unix.go

@@ -50,13 +50,11 @@ func withRemappedSnapshotBase(id string, i Image, uid, gid uint32, readonly bool
 			return err
 		}
 
-		setSnapshotterIfEmpty(ctx, client, c)
-
 		var (
 			parent   = identity.ChainID(diffIDs).String()
 			usernsID = fmt.Sprintf("%s-%d-%d", parent, uid, gid)
 		)
-		snapshotter, err := client.getSnapshotter(c.Snapshotter)
+		snapshotter, err := client.getSnapshotter(ctx, c.Snapshotter)
 		if err != nil {
 			return err
 		}

image.go

@@ -108,7 +108,7 @@ func (i *image) Config(ctx context.Context) (ocispec.Descriptor, error) {
 }
 
 func (i *image) IsUnpacked(ctx context.Context, snapshotterName string) (bool, error) {
-	sn, err := i.client.getSnapshotter(snapshotterName)
+	sn, err := i.client.getSnapshotter(ctx, snapshotterName)
 	if err != nil {
 		return false, err
 	}
@@ -149,7 +149,7 @@ func (i *image) Unpack(ctx context.Context, snapshotterName string) error {
 		chain    []digest.Digest
 		unpacked bool
 	)
-	sn, err := i.client.getSnapshotter(snapshotterName)
+	sn, err := i.client.getSnapshotter(ctx, snapshotterName)
 	if err != nil {
 		return err
 	}