Implement incremental file sync using client session

Also exposes shared cache and garbage collection/prune
for the source data.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Upstream-commit: 5c3d2d552b0430672d5f481ab2d37036f6e92166
Component: engine

components/engine/client/build_prune.go

@@ -0,0 +1,30 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/docker/docker/api/types"
+	"golang.org/x/net/context"
+)
+
+// BuildCachePrune requests the daemon to delete unused cache data
+func (cli *Client) BuildCachePrune(ctx context.Context) (*types.BuildCachePruneReport, error) {
+	if err := cli.NewVersionError("1.31", "build prune"); err != nil {
+		return nil, err
+	}
+
+	report := types.BuildCachePruneReport{}
+
+	serverResp, err := cli.post(ctx, "/build/prune", nil, nil, nil)
+	if err != nil {
+		return nil, err
+	}
+	defer ensureReaderClosed(serverResp)
+
+	if err := json.NewDecoder(serverResp.body).Decode(&report); err != nil {
+		return nil, fmt.Errorf("Error retrieving disk usage: %v", err)
+	}
+
+	return &report, nil
+}

components/engine/client/interface.go

@@ -82,6 +82,7 @@ type DistributionAPIClient interface {
 // ImageAPIClient defines API client methods for the images
 type ImageAPIClient interface {
 	ImageBuild(ctx context.Context, context io.Reader, options types.ImageBuildOptions) (types.ImageBuildResponse, error)
+	BuildCachePrune(ctx context.Context) (*types.BuildCachePruneReport, error)
 	ImageCreate(ctx context.Context, parentReference string, options types.ImageCreateOptions) (io.ReadCloser, error)
 	ImageHistory(ctx context.Context, image string) ([]image.HistoryResponseItem, error)
 	ImageImport(ctx context.Context, source types.ImageImportSource, ref string, options types.ImageImportOptions) (io.ReadCloser, error)

components/engine/client/session/filesync/diffcopy.go

@@ -0,0 +1,30 @@
+package filesync
+
+import (
+	"time"
+
+	"google.golang.org/grpc"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/tonistiigi/fsutil"
+)
+
+func sendDiffCopy(stream grpc.Stream, dir string, excludes []string, progress progressCb) error {
+	return fsutil.Send(stream.Context(), stream, dir, &fsutil.WalkOpt{
+		ExcludePatterns: excludes,
+	}, progress)
+}
+
+func recvDiffCopy(ds grpc.Stream, dest string, cu CacheUpdater) error {
+	st := time.Now()
+	defer func() {
+		logrus.Debugf("diffcopy took: %v", time.Since(st))
+	}()
+	var cf fsutil.ChangeFunc
+	if cu != nil {
+		cu.MarkSupported(true)
+		cf = cu.HandleChange
+	}
+
+	return fsutil.Receive(ds.Context(), ds, dest, cf)
+}

components/engine/client/session/filesync/filesync.go

@@ -0,0 +1,173 @@
+package filesync
+
+import (
+	"os"
+	"strings"
+
+	"github.com/docker/docker/client/session"
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/fsutil"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+type fsSyncProvider struct {
+	root     string
+	excludes []string
+	p        progressCb
+	doneCh   chan error
+}
+
+// NewFSSyncProvider creates a new provider for sending files from client
+func NewFSSyncProvider(root string, excludes []string) session.Attachable {
+	p := &fsSyncProvider{
+		root:     root,
+		excludes: excludes,
+	}
+	return p
+}
+
+func (sp *fsSyncProvider) Register(server *grpc.Server) {
+	RegisterFileSyncServer(server, sp)
+}
+
+func (sp *fsSyncProvider) DiffCopy(stream FileSync_DiffCopyServer) error {
+	return sp.handle("diffcopy", stream)
+}
+func (sp *fsSyncProvider) TarStream(stream FileSync_TarStreamServer) error {
+	return sp.handle("tarstream", stream)
+}
+
+func (sp *fsSyncProvider) handle(method string, stream grpc.ServerStream) error {
+	var pr *protocol
+	for _, p := range supportedProtocols {
+		if method == p.name && isProtoSupported(p.name) {
+			pr = &p
+			break
+		}
+	}
+	if pr == nil {
+		return errors.New("failed to negotiate protocol")
+	}
+
+	opts, _ := metadata.FromContext(stream.Context()) // if no metadata continue with empty object
+
+	var excludes []string
+	if len(opts["Override-Excludes"]) == 0 || opts["Override-Excludes"][0] != "true" {
+		excludes = sp.excludes
+	}
+
+	var progress progressCb
+	if sp.p != nil {
+		progress = sp.p
+		sp.p = nil
+	}
+
+	var doneCh chan error
+	if sp.doneCh != nil {
+		doneCh = sp.doneCh
+		sp.doneCh = nil
+	}
+	err := pr.sendFn(stream, sp.root, excludes, progress)
+	if doneCh != nil {
+		if err != nil {
+			doneCh <- err
+		}
+		close(doneCh)
+	}
+	return err
+}
+
+func (sp *fsSyncProvider) SetNextProgressCallback(f func(int, bool), doneCh chan error) {
+	sp.p = f
+	sp.doneCh = doneCh
+}
+
+type progressCb func(int, bool)
+
+type protocol struct {
+	name   string
+	sendFn func(stream grpc.Stream, srcDir string, excludes []string, progress progressCb) error
+	recvFn func(stream grpc.Stream, destDir string, cu CacheUpdater) error
+}
+
+func isProtoSupported(p string) bool {
+	// TODO: this should be removed after testing if stability is confirmed
+	if override := os.Getenv("BUILD_STREAM_PROTOCOL"); override != "" {
+		return strings.EqualFold(p, override)
+	}
+	return true
+}
+
+var supportedProtocols = []protocol{
+	{
+		name:   "diffcopy",
+		sendFn: sendDiffCopy,
+		recvFn: recvDiffCopy,
+	},
+	{
+		name:   "tarstream",
+		sendFn: sendTarStream,
+		recvFn: recvTarStream,
+	},
+}
+
+// FSSendRequestOpt defines options for FSSend request
+type FSSendRequestOpt struct {
+	SrcPaths         []string
+	OverrideExcludes bool
+	DestDir          string
+	CacheUpdater     CacheUpdater
+}
+
+// CacheUpdater is an object capable of sending notifications for the cache hash changes
+type CacheUpdater interface {
+	MarkSupported(bool)
+	HandleChange(fsutil.ChangeKind, string, os.FileInfo, error) error
+}
+
+// FSSync initializes a transfer of files
+func FSSync(ctx context.Context, c session.Caller, opt FSSendRequestOpt) error {
+	var pr *protocol
+	for _, p := range supportedProtocols {
+		if isProtoSupported(p.name) && c.Supports(session.MethodURL(_FileSync_serviceDesc.ServiceName, p.name)) {
+			pr = &p
+			break
+		}
+	}
+	if pr == nil {
+		return errors.New("no fssync handlers")
+	}
+
+	opts := make(map[string][]string)
+	if opt.OverrideExcludes {
+		opts["Override-Excludes"] = []string{"true"}
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	client := NewFileSyncClient(c.Conn())
+
+	var stream grpc.ClientStream
+
+	ctx = metadata.NewContext(ctx, opts)
+
+	switch pr.name {
+	case "tarstream":
+		cc, err := client.TarStream(ctx)
+		if err != nil {
+			return err
+		}
+		stream = cc
+	case "diffcopy":
+		cc, err := client.DiffCopy(ctx)
+		if err != nil {
+			return err
+		}
+		stream = cc
+	}
+
+	return pr.recvFn(stream, opt.DestDir, opt.CacheUpdater)
+}

components/engine/client/session/filesync/filesync.pb.go

@@ -0,0 +1,575 @@
+// Code generated by protoc-gen-gogo.
+// source: filesync.proto
+// DO NOT EDIT!
+
+/*
+Package filesync is a generated protocol buffer package.
+
+It is generated from these files:
+	filesync.proto
+
+It has these top-level messages:
+	BytesMessage
+*/
+package filesync
+
+import proto "github.com/gogo/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+import bytes "bytes"
+
+import strings "strings"
+import reflect "reflect"
+
+import (
+	context "golang.org/x/net/context"
+	grpc "google.golang.org/grpc"
+)
+
+import io "io"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package
+
+// BytesMessage contains a chunk of byte data
+type BytesMessage struct {
+	Data []byte `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (m *BytesMessage) Reset()                    { *m = BytesMessage{} }
+func (*BytesMessage) ProtoMessage()               {}
+func (*BytesMessage) Descriptor() ([]byte, []int) { return fileDescriptorFilesync, []int{0} }
+
+func (m *BytesMessage) GetData() []byte {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*BytesMessage)(nil), "moby.filesync.v1.BytesMessage")
+}
+func (this *BytesMessage) Equal(that interface{}) bool {
+	if that == nil {
+		if this == nil {
+			return true
+		}
+		return false
+	}
+
+	that1, ok := that.(*BytesMessage)
+	if !ok {
+		that2, ok := that.(BytesMessage)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		if this == nil {
+			return true
+		}
+		return false
+	} else if this == nil {
+		return false
+	}
+	if !bytes.Equal(this.Data, that1.Data) {
+		return false
+	}
+	return true
+}
+func (this *BytesMessage) GoString() string {
+	if this == nil {
+		return "nil"
+	}
+	s := make([]string, 0, 5)
+	s = append(s, "&filesync.BytesMessage{")
+	s = append(s, "Data: "+fmt.Sprintf("%#v", this.Data)+",\n")
+	s = append(s, "}")
+	return strings.Join(s, "")
+}
+func valueToGoStringFilesync(v interface{}, typ string) string {
+	rv := reflect.ValueOf(v)
+	if rv.IsNil() {
+		return "nil"
+	}
+	pv := reflect.Indirect(rv).Interface()
+	return fmt.Sprintf("func(v %v) *%v { return &v } ( %#v )", typ, typ, pv)
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// Client API for FileSync service
+
+type FileSyncClient interface {
+	DiffCopy(ctx context.Context, opts ...grpc.CallOption) (FileSync_DiffCopyClient, error)
+	TarStream(ctx context.Context, opts ...grpc.CallOption) (FileSync_TarStreamClient, error)
+}
+
+type fileSyncClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewFileSyncClient(cc *grpc.ClientConn) FileSyncClient {
+	return &fileSyncClient{cc}
+}
+
+func (c *fileSyncClient) DiffCopy(ctx context.Context, opts ...grpc.CallOption) (FileSync_DiffCopyClient, error) {
+	stream, err := grpc.NewClientStream(ctx, &_FileSync_serviceDesc.Streams[0], c.cc, "/moby.filesync.v1.FileSync/DiffCopy", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &fileSyncDiffCopyClient{stream}
+	return x, nil
+}
+
+type FileSync_DiffCopyClient interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ClientStream
+}
+
+type fileSyncDiffCopyClient struct {
+	grpc.ClientStream
+}
+
+func (x *fileSyncDiffCopyClient) Send(m *BytesMessage) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *fileSyncDiffCopyClient) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func (c *fileSyncClient) TarStream(ctx context.Context, opts ...grpc.CallOption) (FileSync_TarStreamClient, error) {
+	stream, err := grpc.NewClientStream(ctx, &_FileSync_serviceDesc.Streams[1], c.cc, "/moby.filesync.v1.FileSync/TarStream", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &fileSyncTarStreamClient{stream}
+	return x, nil
+}
+
+type FileSync_TarStreamClient interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ClientStream
+}
+
+type fileSyncTarStreamClient struct {
+	grpc.ClientStream
+}
+
+func (x *fileSyncTarStreamClient) Send(m *BytesMessage) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *fileSyncTarStreamClient) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+// Server API for FileSync service
+
+type FileSyncServer interface {
+	DiffCopy(FileSync_DiffCopyServer) error
+	TarStream(FileSync_TarStreamServer) error
+}
+
+func RegisterFileSyncServer(s *grpc.Server, srv FileSyncServer) {
+	s.RegisterService(&_FileSync_serviceDesc, srv)
+}
+
+func _FileSync_DiffCopy_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(FileSyncServer).DiffCopy(&fileSyncDiffCopyServer{stream})
+}
+
+type FileSync_DiffCopyServer interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ServerStream
+}
+
+type fileSyncDiffCopyServer struct {
+	grpc.ServerStream
+}
+
+func (x *fileSyncDiffCopyServer) Send(m *BytesMessage) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *fileSyncDiffCopyServer) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func _FileSync_TarStream_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(FileSyncServer).TarStream(&fileSyncTarStreamServer{stream})
+}
+
+type FileSync_TarStreamServer interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ServerStream
+}
+
+type fileSyncTarStreamServer struct {
+	grpc.ServerStream
+}
+
+func (x *fileSyncTarStreamServer) Send(m *BytesMessage) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *fileSyncTarStreamServer) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+var _FileSync_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "moby.filesync.v1.FileSync",
+	HandlerType: (*FileSyncServer)(nil),
+	Methods:     []grpc.MethodDesc{},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "DiffCopy",
+			Handler:       _FileSync_DiffCopy_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+		{
+			StreamName:    "TarStream",
+			Handler:       _FileSync_TarStream_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
+	},
+	Metadata: "filesync.proto",
+}
+
+func (m *BytesMessage) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *BytesMessage) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Data) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintFilesync(dAtA, i, uint64(len(m.Data)))
+		i += copy(dAtA[i:], m.Data)
+	}
+	return i, nil
+}
+
+func encodeFixed64Filesync(dAtA []byte, offset int, v uint64) int {
+	dAtA[offset] = uint8(v)
+	dAtA[offset+1] = uint8(v >> 8)
+	dAtA[offset+2] = uint8(v >> 16)
+	dAtA[offset+3] = uint8(v >> 24)
+	dAtA[offset+4] = uint8(v >> 32)
+	dAtA[offset+5] = uint8(v >> 40)
+	dAtA[offset+6] = uint8(v >> 48)
+	dAtA[offset+7] = uint8(v >> 56)
+	return offset + 8
+}
+func encodeFixed32Filesync(dAtA []byte, offset int, v uint32) int {
+	dAtA[offset] = uint8(v)
+	dAtA[offset+1] = uint8(v >> 8)
+	dAtA[offset+2] = uint8(v >> 16)
+	dAtA[offset+3] = uint8(v >> 24)
+	return offset + 4
+}
+func encodeVarintFilesync(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *BytesMessage) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Data)
+	if l > 0 {
+		n += 1 + l + sovFilesync(uint64(l))
+	}
+	return n
+}
+
+func sovFilesync(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozFilesync(x uint64) (n int) {
+	return sovFilesync(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (this *BytesMessage) String() string {
+	if this == nil {
+		return "nil"
+	}
+	s := strings.Join([]string{`&BytesMessage{`,
+		`Data:` + fmt.Sprintf("%v", this.Data) + `,`,
+		`}`,
+	}, "")
+	return s
+}
+func valueToStringFilesync(v interface{}) string {
+	rv := reflect.ValueOf(v)
+	if rv.IsNil() {
+		return "nil"
+	}
+	pv := reflect.Indirect(rv).Interface()
+	return fmt.Sprintf("*%v", pv)
+}
+func (m *BytesMessage) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowFilesync
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: BytesMessage: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: BytesMessage: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Data", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowFilesync
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthFilesync
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Data = append(m.Data[:0], dAtA[iNdEx:postIndex]...)
+			if m.Data == nil {
+				m.Data = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipFilesync(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthFilesync
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipFilesync(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowFilesync
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowFilesync
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowFilesync
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthFilesync
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowFilesync
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipFilesync(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthFilesync = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowFilesync   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("filesync.proto", fileDescriptorFilesync) }
+
+var fileDescriptorFilesync = []byte{
+	// 198 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x09, 0x6e, 0x88, 0x02, 0xff, 0xe2, 0xe2, 0x4b, 0xcb, 0xcc, 0x49,
+	0x2d, 0xae, 0xcc, 0x4b, 0xd6, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x12, 0xc8, 0xcd, 0x4f, 0xaa,
+	0xd4, 0x83, 0x0b, 0x96, 0x19, 0x2a, 0x29, 0x71, 0xf1, 0x38, 0x55, 0x96, 0xa4, 0x16, 0xfb, 0xa6,
+	0x16, 0x17, 0x27, 0xa6, 0xa7, 0x0a, 0x09, 0x71, 0xb1, 0xa4, 0x24, 0x96, 0x24, 0x4a, 0x30, 0x2a,
+	0x30, 0x6a, 0xf0, 0x04, 0x81, 0xd9, 0x46, 0xab, 0x19, 0xb9, 0x38, 0xdc, 0x32, 0x73, 0x52, 0x83,
+	0x2b, 0xf3, 0x92, 0x85, 0xfc, 0xb8, 0x38, 0x5c, 0x32, 0xd3, 0xd2, 0x9c, 0xf3, 0x0b, 0x2a, 0x85,
+	0xe4, 0xf4, 0xd0, 0xcd, 0xd3, 0x43, 0x36, 0x4c, 0x8a, 0x80, 0xbc, 0x06, 0xa3, 0x01, 0xa3, 0x90,
+	0x3f, 0x17, 0x67, 0x48, 0x62, 0x51, 0x70, 0x49, 0x51, 0x6a, 0x62, 0x2e, 0x35, 0x0c, 0x74, 0x32,
+	0xbb, 0xf0, 0x50, 0x8e, 0xe1, 0xc6, 0x43, 0x39, 0x86, 0x0f, 0x0f, 0xe5, 0x18, 0x1b, 0x1e, 0xc9,
+	0x31, 0xae, 0x78, 0x24, 0xc7, 0x78, 0xe2, 0x91, 0x1c, 0xe3, 0x85, 0x47, 0x72, 0x8c, 0x0f, 0x1e,
+	0xc9, 0x31, 0xbe, 0x78, 0x24, 0xc7, 0xf0, 0xe1, 0x91, 0x1c, 0xe3, 0x84, 0xc7, 0x72, 0x0c, 0x51,
+	0x1c, 0x30, 0xb3, 0x92, 0xd8, 0xc0, 0x41, 0x64, 0x0c, 0x08, 0x00, 0x00, 0xff, 0xff, 0x5f, 0x0c,
+	0x8d, 0xc5, 0x34, 0x01, 0x00, 0x00,
+}

components/engine/client/session/filesync/filesync.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package moby.filesync.v1;
+
+option go_package = "filesync";
+
+service FileSync{
+  rpc DiffCopy(stream BytesMessage) returns (stream BytesMessage);
+  rpc TarStream(stream BytesMessage) returns (stream BytesMessage);
+}
+
+// BytesMessage contains a chunk of byte data
+message BytesMessage{
+	bytes data = 1;
+}

components/engine/client/session/filesync/generate.go

@@ -0,0 +1,3 @@
+package filesync
+
+//go:generate protoc --gogoslick_out=plugins=grpc:. filesync.proto

components/engine/client/session/filesync/tarstream.go

@@ -0,0 +1,83 @@
+package filesync
+
+import (
+	"io"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/chrootarchive"
+	"github.com/pkg/errors"
+	"google.golang.org/grpc"
+)
+
+func sendTarStream(stream grpc.Stream, dir string, excludes []string, progress progressCb) error {
+	a, err := archive.TarWithOptions(dir, &archive.TarOptions{
+		ExcludePatterns: excludes,
+	})
+	if err != nil {
+		return err
+	}
+
+	size := 0
+	buf := make([]byte, 1<<15)
+	t := new(BytesMessage)
+	for {
+		n, err := a.Read(buf)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+		t.Data = buf[:n]
+
+		if err := stream.SendMsg(t); err != nil {
+			return err
+		}
+		size += n
+		if progress != nil {
+			progress(size, false)
+		}
+	}
+	if progress != nil {
+		progress(size, true)
+	}
+	return nil
+}
+
+func recvTarStream(ds grpc.Stream, dest string, cs CacheUpdater) error {
+
+	pr, pw := io.Pipe()
+
+	go func() {
+		var (
+			err error
+			t   = new(BytesMessage)
+		)
+		for {
+			if err = ds.RecvMsg(t); err != nil {
+				if err == io.EOF {
+					err = nil
+				}
+				break
+			}
+			_, err = pw.Write(t.Data)
+			if err != nil {
+				break
+			}
+		}
+		if err = pw.CloseWithError(err); err != nil {
+			logrus.Errorf("failed to close tar transfer pipe")
+		}
+	}()
+
+	decompressedStream, err := archive.DecompressStream(pr)
+	if err != nil {
+		return errors.Wrap(err, "failed to decompress stream")
+	}
+
+	if err := chrootarchive.Untar(decompressedStream, dest, nil); err != nil {
+		return errors.Wrap(err, "failed to untar context")
+	}
+	return nil
+}