snapshots: emit deprecation warning for aufs

Signed-off-by: Samuel Karp <samuelkarp@google.com>
(cherry picked from commit 625b35e)
Signed-off-by: Samuel Karp <samuelkarp@google.com>

pkg/deprecation/deprecation.go

@@ -33,6 +33,8 @@ const (
 	CRIRegistryConfigs Warning = Prefix + "cri-registry-configs"
 	// CRIAPIV1Alpha2 is a warning for the use of CRI-API v1alpha2
 	CRIAPIV1Alpha2 Warning = Prefix + "cri-api-v1alpha2"
+	// AUFSSnapshotter is a warning for the use of the aufs snapshotter
+	AUFSSnapshotter Warning = Prefix + "aufs-snapshotter"
 )
 
 var messages = map[Warning]string{
@@ -45,7 +47,8 @@ var messages = map[Warning]string{
 		"Use `ImagePullSecrets` instead.",
 	CRIRegistryConfigs: "The `configs` property of `[plugins.\"io.containerd.grpc.v1.cri\".registry]` is deprecated since containerd v1.5 and will be removed in containerd v2.0." +
 		"Use `config_path` instead.",
-	CRIAPIV1Alpha2: "CRI API v1alpha2 is deprecated since containerd v1.7 and removed in containerd v2.0. Use CRI API v1 instead.",
+	CRIAPIV1Alpha2:  "CRI API v1alpha2 is deprecated since containerd v1.7 and removed in containerd v2.0. Use CRI API v1 instead.",
+	AUFSSnapshotter: "The aufs snapshotter is deprecated since containerd v1.5 and removed in containerd v2.0. Use the overlay snapshotter instead.",
 }
 
 // Valid checks whether a given Warning is valid

services/snapshots/service.go

@@ -25,8 +25,10 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/pkg/deprecation"
 	"github.com/containerd/containerd/plugin"
 	"github.com/containerd/containerd/services"
+	"github.com/containerd/containerd/services/warning"
 	"github.com/containerd/containerd/snapshots"
 	ptypes "github.com/gogo/protobuf/types"
 	"google.golang.org/grpc"
@@ -38,6 +40,7 @@ func init() {
 		ID:   "snapshots",
 		Requires: []plugin.Type{
 			plugin.ServicePlugin,
+			plugin.WarningPlugin,
 		},
 		InitFn: newService,
 	})
@@ -46,7 +49,8 @@ func init() {
 var empty = &ptypes.Empty{}
 
 type service struct {
-	ss map[string]snapshots.Snapshotter
+	ss       map[string]snapshots.Snapshotter
+	warnings warning.Service
 }
 
 func newService(ic *plugin.InitContext) (interface{}, error) {
@@ -63,7 +67,14 @@ func newService(ic *plugin.InitContext) (interface{}, error) {
 		return nil, err
 	}
 	ss := i.(map[string]snapshots.Snapshotter)
-	return &service{ss: ss}, nil
+	w, err := ic.Get(plugin.WarningPlugin)
+	if err != nil {
+		return nil, err
+	}
+	return &service{
+		ss:       ss,
+		warnings: w.(warning.Service),
+	}, nil
 }
 
 func (s *service) getSnapshotter(name string) (snapshots.Snapshotter, error) {
@@ -145,6 +156,7 @@ func (s *service) Commit(ctx context.Context, cr *snapshotsapi.CommitSnapshotReq
 	if err != nil {
 		return nil, err
 	}
+	s.emitSnapshotterWarning(ctx, cr.Snapshotter)
 
 	var opts []snapshots.Opt
 	if cr.Labels != nil {
@@ -274,6 +286,14 @@ func (s *service) Cleanup(ctx context.Context, cr *snapshotsapi.CleanupRequest)
 	return empty, nil
 }
 
+func (s *service) emitSnapshotterWarning(ctx context.Context, sn string) {
+	switch sn {
+	case "aufs":
+		log.G(ctx).Warn("aufs snapshotter is deprecated")
+		s.warnings.Emit(ctx, deprecation.AUFSSnapshotter)
+	}
+}
+
 func fromKind(kind snapshots.Kind) snapshotsapi.Kind {
 	if kind == snapshots.KindActive {
 		return snapshotsapi.KindActive