Add synchronous image delete

Synchronous image delete provides an option image delete to wait
until the next garbage collection deletes after an image is removed
before returning success to the caller.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

api/next.pb.txt

@@ -2193,6 +2193,13 @@ file {
       type: TYPE_STRING
       json_name: "name"
     }
+    field {
+      name: "sync"
+      number: 2
+      label: LABEL_OPTIONAL
+      type: TYPE_BOOL
+      json_name: "sync"
+    }
   }
   service {
     name: "Images"

api/services/images/v1/images.pb.go

@@ -163,6 +163,9 @@ func (*ListImagesResponse) Descriptor() ([]byte, []int) { return fileDescriptorI
 
 type DeleteImageRequest struct {
 	Name string `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	// Sync indicates that the delete and cleanup should be done
+	// synchronously before returning to the caller
+	Sync bool `protobuf:"varint,2,opt,name=sync,proto3" json:"sync,omitempty"`
 }
 
 func (m *DeleteImageRequest) Reset()                    { *m = DeleteImageRequest{} }
@@ -717,6 +720,16 @@ func (m *DeleteImageRequest) MarshalTo(dAtA []byte) (int, error) {
 		i = encodeVarintImages(dAtA, i, uint64(len(m.Name)))
 		i += copy(dAtA[i:], m.Name)
 	}
+	if m.Sync {
+		dAtA[i] = 0x10
+		i++
+		if m.Sync {
+			dAtA[i] = 1
+		} else {
+			dAtA[i] = 0
+		}
+		i++
+	}
 	return i, nil
 }
 
@@ -840,6 +853,9 @@ func (m *DeleteImageRequest) Size() (n int) {
 	if l > 0 {
 		n += 1 + l + sovImages(uint64(l))
 	}
+	if m.Sync {
+		n += 2
+	}
 	return n
 }
 
@@ -967,6 +983,7 @@ func (this *DeleteImageRequest) String() string {
 	}
 	s := strings.Join([]string{`&DeleteImageRequest{`,
 		`Name:` + fmt.Sprintf("%v", this.Name) + `,`,
+		`Sync:` + fmt.Sprintf("%v", this.Sync) + `,`,
 		`}`,
 	}, "")
 	return s
@@ -1999,6 +2016,26 @@ func (m *DeleteImageRequest) Unmarshal(dAtA []byte) error {
 			}
 			m.Name = string(dAtA[iNdEx:postIndex])
 			iNdEx = postIndex
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Sync", wireType)
+			}
+			var v int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowImages
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				v |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			m.Sync = bool(v != 0)
 		default:
 			iNdEx = preIndex
 			skippy, err := skipImages(dAtA[iNdEx:])
@@ -2130,46 +2167,47 @@ func init() {
 }
 
 var fileDescriptorImages = []byte{
-	// 650 bytes of a gzipped FileDescriptorProto
+	// 659 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x55, 0x4f, 0x6f, 0xd3, 0x4e,
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x55, 0xcd, 0x6e, 0xd3, 0x40,
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+	0x07, 0x00, 0x00,
 }

api/services/images/v1/images.proto

@@ -115,4 +115,8 @@ message ListImagesResponse {
 
 message DeleteImageRequest {
 	string name = 1;
+
+	// Sync indicates that the delete and cleanup should be done
+	// synchronously before returning to the caller
+	bool sync = 2;
 }

cmd/containerd/builtins.go

@@ -3,7 +3,7 @@ package main
 // register containerd builtins here
 import (
 	_ "github.com/containerd/containerd/diff/walking"
-	_ "github.com/containerd/containerd/gc/policy"
+	_ "github.com/containerd/containerd/gc/scheduler"
 	_ "github.com/containerd/containerd/services/containers"
 	_ "github.com/containerd/containerd/services/content"
 	_ "github.com/containerd/containerd/services/diff"

cmd/ctr/commands/images/images.go

@@ -270,8 +270,14 @@ var removeCommand = cli.Command{
 	Name:        "remove",
 	Aliases:     []string{"rm"},
 	Usage:       "remove one or more images by reference",
-	ArgsUsage:   "<ref> [<ref>, ...]",
+	ArgsUsage:   "[flags] <ref> [<ref>, ...]",
 	Description: "remove one or more images by reference",
+	Flags: []cli.Flag{
+		cli.BoolFlag{
+			Name:  "sync",
+			Usage: "Synchronously remove image and all associated resources",
+		},
+	},
 	Action: func(context *cli.Context) error {
 		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {
@@ -282,8 +288,12 @@ var removeCommand = cli.Command{
 			exitErr    error
 			imageStore = client.ImageService()
 		)
-		for _, target := range context.Args() {
+		for i, target := range context.Args() {
-			if err := imageStore.Delete(ctx, target); err != nil {
+			var opts []images.DeleteOpt
+			if context.Bool("sync") && i == context.NArg()-1 {
+				opts = append(opts, images.SynchronousDelete())
+			}
+			if err := imageStore.Delete(ctx, target, opts...); err != nil {
 				if !errdefs.IsNotFound(err) {
 					if exitErr == nil {
 						exitErr = errors.Wrapf(err, "unable to delete %v", target)

image_store.go

@@ -74,9 +74,16 @@ func (s *remoteImages) Update(ctx context.Context, image images.Image, fieldpath
 	return imageFromProto(&updated.Image), nil
 }
 
-func (s *remoteImages) Delete(ctx context.Context, name string) error {
+func (s *remoteImages) Delete(ctx context.Context, name string, opts ...images.DeleteOpt) error {
+	var do images.DeleteOptions
+	for _, opt := range opts {
+		if err := opt(ctx, &do); err != nil {
+			return err
+		}
+	}
 	_, err := s.client.Delete(ctx, &imagesapi.DeleteImageRequest{
 		Name: name,
+		Sync: do.Synchronous,
 	})
 
 	return errdefs.FromGRPC(err)

images/image.go

@@ -38,6 +38,23 @@ type Image struct {
 	CreatedAt, UpdatedAt time.Time
 }
 
+// DeleteOptions provide options on image delete
+type DeleteOptions struct {
+	Synchronous bool
+}
+
+// DeleteOpt allows configuring a delete operation
+type DeleteOpt func(context.Context, *DeleteOptions) error
+
+// SynchronousDelete is used to indicate that an image deletion and removal of
+// the image resources should occur synchronously before returning a result.
+func SynchronousDelete() DeleteOpt {
+	return func(ctx context.Context, o *DeleteOptions) error {
+		o.Synchronous = true
+		return nil
+	}
+}
+
 // Store and interact with images
 type Store interface {
 	Get(ctx context.Context, name string) (Image, error)
@@ -48,7 +65,7 @@ type Store interface {
 	// one or more fieldpaths are provided, only those fields will be updated.
 	Update(ctx context.Context, image Image, fieldpaths ...string) (Image, error)
 
-	Delete(ctx context.Context, name string) error
+	Delete(ctx context.Context, name string, opts ...DeleteOpt) error
 }
 
 // TODO(stevvooe): Many of these functions make strong platform assumptions,

metadata/images.go

@@ -187,7 +187,7 @@ func (s *imageStore) Update(ctx context.Context, image images.Image, fieldpaths
 	})
 }
 
-func (s *imageStore) Delete(ctx context.Context, name string) error {
+func (s *imageStore) Delete(ctx context.Context, name string, opts ...images.DeleteOpt) error {
 	namespace, err := namespaces.NamespaceRequired(ctx)
 	if err != nil {
 		return err

services/images/service.go

@@ -1,6 +1,8 @@
 package images
 
 import (
+	gocontext "context"
+
 	"github.com/boltdb/bolt"
 	eventstypes "github.com/containerd/containerd/api/events"
 	imagesapi "github.com/containerd/containerd/api/services/images/v1"
@@ -22,26 +24,38 @@ func init() {
 		ID:   "images",
 		Requires: []plugin.Type{
 			plugin.MetadataPlugin,
+			plugin.GCPlugin,
 		},
 		InitFn: func(ic *plugin.InitContext) (interface{}, error) {
 			m, err := ic.Get(plugin.MetadataPlugin)
 			if err != nil {
 				return nil, err
 			}
-			return NewService(m.(*metadata.DB), ic.Events), nil
+			g, err := ic.Get(plugin.GCPlugin)
+			if err != nil {
+				return nil, err
+			}
+
+			return NewService(m.(*metadata.DB), g.(gcScheduler), ic.Events), nil
 		},
 	})
 }
 
+type gcScheduler interface {
+	ScheduleAndWait(gocontext.Context) (metadata.GCStats, error)
+}
+
 type service struct {
 	db        *metadata.DB
+	gc        gcScheduler
 	publisher events.Publisher
 }
 
 // NewService returns the GRPC image server
-func NewService(db *metadata.DB, publisher events.Publisher) imagesapi.ImagesServer {
+func NewService(db *metadata.DB, gc gcScheduler, publisher events.Publisher) imagesapi.ImagesServer {
 	return &service{
 		db:        db,
+		gc:        gc,
 		publisher: publisher,
 	}
 }
@@ -162,6 +176,12 @@ func (s *service) Delete(ctx context.Context, req *imagesapi.DeleteImageRequest)
 		return nil, err
 	}
 
+	if req.Sync {
+		if _, err := s.gc.ScheduleAndWait(ctx); err != nil {
+			return nil, err
+		}
+	}
+
 	return &ptypes.Empty{}, nil
 }