Merge pull request #71 from tonistiigi/local-session

source: add local file source fundamentals

api/services/control/control.pb.go

@@ -19,6 +19,7 @@
 		Vertex
 		VertexStatus
 		VertexLog
+		BytesMessage
 */
 package moby_buildkit_v1
 
@@ -121,6 +122,7 @@ type SolveRequest struct {
 	Definition    [][]byte          `protobuf:"bytes,2,rep,name=Definition" json:"Definition,omitempty"`
 	Exporter      string            `protobuf:"bytes,3,opt,name=Exporter,proto3" json:"Exporter,omitempty"`
 	ExporterAttrs map[string]string `protobuf:"bytes,4,rep,name=ExporterAttrs" json:"ExporterAttrs,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	Session       string            `protobuf:"bytes,5,opt,name=Session,proto3" json:"Session,omitempty"`
 }
 
 func (m *SolveRequest) Reset()                    { *m = SolveRequest{} }
@@ -156,6 +158,13 @@ func (m *SolveRequest) GetExporterAttrs() map[string]string {
 	return nil
 }
 
+func (m *SolveRequest) GetSession() string {
+	if m != nil {
+		return m.Session
+	}
+	return ""
+}
+
 type SolveResponse struct {
 	Vtx []*Vertex `protobuf:"bytes,1,rep,name=vtx" json:"vtx,omitempty"`
 }
@@ -369,6 +378,22 @@ func (m *VertexLog) GetMsg() []byte {
 	return nil
 }
 
+type BytesMessage struct {
+	Data []byte `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
+}
+
+func (m *BytesMessage) Reset()                    { *m = BytesMessage{} }
+func (m *BytesMessage) String() string            { return proto.CompactTextString(m) }
+func (*BytesMessage) ProtoMessage()               {}
+func (*BytesMessage) Descriptor() ([]byte, []int) { return fileDescriptorControl, []int{10} }
+
+func (m *BytesMessage) GetData() []byte {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
 func init() {
 	proto.RegisterType((*DiskUsageRequest)(nil), "moby.buildkit.v1.DiskUsageRequest")
 	proto.RegisterType((*DiskUsageResponse)(nil), "moby.buildkit.v1.DiskUsageResponse")
@@ -380,6 +405,7 @@ func init() {
 	proto.RegisterType((*Vertex)(nil), "moby.buildkit.v1.Vertex")
 	proto.RegisterType((*VertexStatus)(nil), "moby.buildkit.v1.VertexStatus")
 	proto.RegisterType((*VertexLog)(nil), "moby.buildkit.v1.VertexLog")
+	proto.RegisterType((*BytesMessage)(nil), "moby.buildkit.v1.BytesMessage")
 }
 
 // Reference imports to suppress errors if they are not otherwise used.
@@ -396,6 +422,7 @@ type ControlClient interface {
 	DiskUsage(ctx context.Context, in *DiskUsageRequest, opts ...grpc.CallOption) (*DiskUsageResponse, error)
 	Solve(ctx context.Context, in *SolveRequest, opts ...grpc.CallOption) (*SolveResponse, error)
 	Status(ctx context.Context, in *StatusRequest, opts ...grpc.CallOption) (Control_StatusClient, error)
+	Session(ctx context.Context, opts ...grpc.CallOption) (Control_SessionClient, error)
 }
 
 type controlClient struct {
@@ -456,12 +483,44 @@ func (x *controlStatusClient) Recv() (*StatusResponse, error) {
 	return m, nil
 }
 
+func (c *controlClient) Session(ctx context.Context, opts ...grpc.CallOption) (Control_SessionClient, error) {
+	stream, err := grpc.NewClientStream(ctx, &_Control_serviceDesc.Streams[1], c.cc, "/moby.buildkit.v1.Control/Session", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &controlSessionClient{stream}
+	return x, nil
+}
+
+type Control_SessionClient interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ClientStream
+}
+
+type controlSessionClient struct {
+	grpc.ClientStream
+}
+
+func (x *controlSessionClient) Send(m *BytesMessage) error {
+	return x.ClientStream.SendMsg(m)
+}
+
+func (x *controlSessionClient) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
 // Server API for Control service
 
 type ControlServer interface {
 	DiskUsage(context.Context, *DiskUsageRequest) (*DiskUsageResponse, error)
 	Solve(context.Context, *SolveRequest) (*SolveResponse, error)
 	Status(*StatusRequest, Control_StatusServer) error
+	Session(Control_SessionServer) error
 }
 
 func RegisterControlServer(s *grpc.Server, srv ControlServer) {
@@ -525,6 +584,32 @@ func (x *controlStatusServer) Send(m *StatusResponse) error {
 	return x.ServerStream.SendMsg(m)
 }
 
+func _Control_Session_Handler(srv interface{}, stream grpc.ServerStream) error {
+	return srv.(ControlServer).Session(&controlSessionServer{stream})
+}
+
+type Control_SessionServer interface {
+	Send(*BytesMessage) error
+	Recv() (*BytesMessage, error)
+	grpc.ServerStream
+}
+
+type controlSessionServer struct {
+	grpc.ServerStream
+}
+
+func (x *controlSessionServer) Send(m *BytesMessage) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func (x *controlSessionServer) Recv() (*BytesMessage, error) {
+	m := new(BytesMessage)
+	if err := x.ServerStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
 var _Control_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "moby.buildkit.v1.Control",
 	HandlerType: (*ControlServer)(nil),
@@ -544,6 +629,12 @@ var _Control_serviceDesc = grpc.ServiceDesc{
 			Handler:       _Control_Status_Handler,
 			ServerStreams: true,
 		},
+		{
+			StreamName:    "Session",
+			Handler:       _Control_Session_Handler,
+			ServerStreams: true,
+			ClientStreams: true,
+		},
 	},
 	Metadata: "control.proto",
 }
@@ -697,6 +788,12 @@ func (m *SolveRequest) MarshalTo(dAtA []byte) (int, error) {
 			i += copy(dAtA[i:], v)
 		}
 	}
+	if len(m.Session) > 0 {
+		dAtA[i] = 0x2a
+		i++
+		i = encodeVarintControl(dAtA, i, uint64(len(m.Session)))
+		i += copy(dAtA[i:], m.Session)
+	}
 	return i, nil
 }
 
@@ -1006,6 +1103,30 @@ func (m *VertexLog) MarshalTo(dAtA []byte) (int, error) {
 	return i, nil
 }
 
+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 = encodeVarintControl(dAtA, i, uint64(len(m.Data)))
+		i += copy(dAtA[i:], m.Data)
+	}
+	return i, nil
+}
+
 func encodeFixed64Control(dAtA []byte, offset int, v uint64) int {
 	dAtA[offset] = uint8(v)
 	dAtA[offset+1] = uint8(v >> 8)
@@ -1095,6 +1216,10 @@ func (m *SolveRequest) Size() (n int) {
 			n += mapEntrySize + 1 + sovControl(uint64(mapEntrySize))
 		}
 	}
+	l = len(m.Session)
+	if l > 0 {
+		n += 1 + l + sovControl(uint64(l))
+	}
 	return n
 }
 
@@ -1232,6 +1357,16 @@ func (m *VertexLog) Size() (n int) {
 	return n
 }
 
+func (m *BytesMessage) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Data)
+	if l > 0 {
+		n += 1 + l + sovControl(uint64(l))
+	}
+	return n
+}
+
 func sovControl(x uint64) (n int) {
 	for {
 		n++
@@ -1746,6 +1881,35 @@ func (m *SolveRequest) Unmarshal(dAtA []byte) error {
 				m.ExporterAttrs[mapkey] = mapvalue
 			}
 			iNdEx = postIndex
+		case 5:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Session", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowControl
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthControl
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Session = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
 		default:
 			iNdEx = preIndex
 			skippy, err := skipControl(dAtA[iNdEx:])
@@ -2752,6 +2916,87 @@ func (m *VertexLog) Unmarshal(dAtA []byte) error {
 	}
 	return nil
 }
+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 ErrIntOverflowControl
+			}
+			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 ErrIntOverflowControl
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthControl
+			}
+			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 := skipControl(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthControl
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
 func skipControl(dAtA []byte) (n int, err error) {
 	l := len(dAtA)
 	iNdEx := 0
@@ -2860,55 +3105,57 @@ var (
 func init() { proto.RegisterFile("control.proto", fileDescriptorControl) }
 
 var fileDescriptorControl = []byte{
-	// 785 bytes of a gzipped FileDescriptorProto
+	// 832 bytes of a gzipped FileDescriptorProto
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-	0x99, 0x78, 0x1b, 0x3c, 0x1e, 0x42, 0x2d, 0x61, 0x91, 0x70, 0x6d, 0xe5, 0xf7, 0xfe, 0x2e, 0xbf,
+	0x86, 0x96, 0xd0, 0x7e, 0x50, 0xe8, 0xba, 0xec, 0x0f, 0xbb, 0xbb, 0xac, 0xec, 0x7d, 0x1b, 0x3c,
-	0xef, 0x58, 0x44, 0x14, 0xd0, 0xbf, 0xb4, 0xc0, 0xd1, 0x77, 0xf8, 0x08, 0x9c, 0x79, 0x1c, 0x51,
+	0x39, 0x82, 0x46, 0xce, 0x52, 0x11, 0x78, 0xda, 0xee, 0xc3, 0x5d, 0x76, 0xdf, 0xb3, 0x94, 0x6a,
-	0x21, 0xf5, 0xab, 0xc6, 0xa3, 0x8b, 0xcb, 0xde, 0x3b, 0xbf, 0x5f, 0xf6, 0x5e, 0x54, 0xa6, 0x88,
+	0x60, 0x74, 0xe5, 0x82, 0x6f, 0xce, 0xc8, 0x29, 0xf8, 0xb3, 0x2c, 0x45, 0x21, 0x4d, 0x56, 0xa3,
-	0x2d, 0x69, 0x56, 0x4c, 0x5d, 0x18, 0x67, 0x94, 0x8b, 0x61, 0xc4, 0x5e, 0x6a, 0x97, 0x60, 0xa2,
+	0xe1, 0x8b, 0xab, 0xde, 0x7b, 0x7f, 0x5d, 0xf5, 0x1e, 0xd4, 0xe6, 0x8b, 0x2d, 0xb1, 0x50, 0xf3,
-	0x7e, 0x88, 0x61, 0x28, 0xb8, 0xe2, 0x6c, 0x99, 0x4b, 0xfd, 0x82, 0x47, 0x72, 0x69, 0x86, 0xa2,
+	0x98, 0x64, 0x05, 0x72, 0x71, 0x94, 0xb2, 0x87, 0xc6, 0x24, 0x1e, 0xeb, 0x0f, 0xb5, 0x1e, 0x94,
-	0x8d, 0xb3, 0x30, 0xa5, 0xa6, 0xd7, 0xd4, 0x19, 0x3f, 0x07, 0x67, 0x16, 0xce, 0xce, 0xe8, 0x5c,
+	0xaf, 0xac, 0x58, 0x96, 0xd2, 0x64, 0x70, 0x47, 0x5f, 0xc6, 0x83, 0x6a, 0xf0, 0x22, 0x59, 0xa0,
-	0x35, 0x77, 0x83, 0x18, 0x0b, 0x1f, 0x40, 0x5d, 0xc8, 0x90, 0x4b, 0x3a, 0x77, 0xf7, 0xfa, 0x68,
+	0xed, 0x42, 0x2d, 0x93, 0xfb, 0xe0, 0x4f, 0x93, 0xe9, 0x73, 0x9c, 0xe9, 0xb6, 0x6f, 0x51, 0xab,
-	0xd0, 0x1a, 0x79, 0x81, 0x1e, 0xea, 0xa0, 0x1c, 0xea, 0xe0, 0x6d, 0x39, 0xd4, 0xe3, 0xda, 0xcf,
+	0x91, 0x63, 0x68, 0x0a, 0x99, 0x70, 0x89, 0x33, 0xdd, 0x40, 0xfb, 0xc3, 0x30, 0x36, 0xe3, 0x1e,
-	0x7f, 0xf4, 0x10, 0x29, 0x1d, 0xf0, 0x97, 0xd0, 0x9c, 0xb1, 0x74, 0x99, 0xd0, 0xc2, 0xdb, 0x79,
+	0x57, 0xe3, 0x1e, 0x3f, 0xad, 0xc6, 0x7d, 0xd4, 0xf8, 0xe5, 0xef, 0x9e, 0x43, 0x2b, 0x03, 0xf2,
-	0xa0, 0xf7, 0xb5, 0x4b, 0xd1, 0x7a, 0x94, 0x73, 0xc6, 0xdd, 0xba, 0x6e, 0x3d, 0x65, 0xf8, 0x7f,
+	0x15, 0xb4, 0xa7, 0x6c, 0xb1, 0xcc, 0x51, 0x59, 0xfb, 0x6f, 0x69, 0xfd, 0xd2, 0x44, 0xb5, 0x1e,
-	0x59, 0xd0, 0xae, 0x16, 0x6b, 0x6b, 0xaa, 0x8f, 0xc0, 0xd1, 0xa5, 0xd7, 0x2d, 0xfb, 0x38, 0xa9,
+	0x72, 0xce, 0x78, 0xd0, 0x34, 0xad, 0xa7, 0x95, 0xe8, 0x5f, 0x17, 0x3a, 0xf5, 0x62, 0x6d, 0xcd,
-	0x34, 0xc3, 0x9d, 0x52, 0xb9, 0x50, 0x9f, 0xe5, 0x9c, 0xd3, 0x4c, 0x9a, 0x45, 0x50, 0x9a, 0x45,
+	0xfb, 0x29, 0xf8, 0xa6, 0xf4, 0xa6, 0x65, 0xef, 0x46, 0x95, 0xf1, 0x70, 0x2b, 0x55, 0x01, 0x34,
-	0xc2, 0x92, 0xc9, 0x30, 0x51, 0x52, 0xd9, 0x44, 0x1b, 0x78, 0x0c, 0xcd, 0xcd, 0xde, 0x7b, 0x80,
+	0xa7, 0x25, 0xe7, 0x58, 0x48, 0xbb, 0x22, 0x2a, 0x55, 0x05, 0x2c, 0x99, 0x4c, 0x72, 0x4d, 0x95,
-	0x0c, 0x8d, 0x22, 0x5d, 0x2d, 0xc5, 0xc6, 0xad, 0x5a, 0x86, 0xfa, 0x93, 0xca, 0xd0, 0xf8, 0xdf,
+	0x47, 0x8d, 0x42, 0x46, 0xd0, 0xde, 0x6c, 0xc4, 0xb7, 0xa0, 0xa1, 0xa5, 0xc2, 0x35, 0x54, 0x6c,
-	0x65, 0xf0, 0x7f, 0x45, 0xd0, 0xdc, 0x74, 0x79, 0x45, 0x5d, 0xf4, 0x64, 0x75, 0x6f, 0x28, 0x63,
+	0xcc, 0xea, 0x65, 0x68, 0xbe, 0x53, 0x19, 0x5a, 0xff, 0xbb, 0x0c, 0xd1, 0xef, 0x0e, 0xb4, 0x37,
-	0x3d, 0x4e, 0x99, 0xe7, 0xe0, 0x08, 0xc9, 0x69, 0x98, 0xaa, 0x1a, 0xd9, 0xc4, 0x58, 0xc5, 0x3e,
+	0x5d, 0x5e, 0x63, 0xd7, 0x79, 0x67, 0x76, 0x6f, 0x30, 0xe3, 0xde, 0x8d, 0x99, 0xfb, 0xe0, 0x0b,
-	0x49, 0x45, 0xa4, 0x2a, 0xd4, 0x26, 0xc5, 0x71, 0xf4, 0x0f, 0x82, 0xfa, 0x37, 0xfa, 0x03, 0x87,
+	0xc9, 0x31, 0x59, 0xe8, 0x1a, 0x79, 0xd4, 0x6a, 0x6a, 0x9f, 0x2c, 0x44, 0xaa, 0x2b, 0xd4, 0xa1,
-	0xdf, 0x42, 0x73, 0xf3, 0x91, 0xc1, 0xfe, 0xf6, 0x54, 0xdf, 0xfe, 0x2a, 0x79, 0x1f, 0xdd, 0x8b,
+	0x4a, 0x8c, 0x22, 0xe8, 0x8c, 0xd6, 0x12, 0xc5, 0x19, 0x0a, 0xf5, 0x5a, 0xa8, 0xda, 0xce, 0x12,
-	0x31, 0xeb, 0xe9, 0x5b, 0xd8, 0x53, 0x1b, 0x11, 0x77, 0xef, 0x5f, 0xcf, 0x5e, 0x6f, 0xe7, 0xff,
+	0x99, 0xe8, 0x3c, 0x3a, 0x54, 0xcb, 0xc3, 0x3f, 0x5c, 0x68, 0x7e, 0x6b, 0x9e, 0x47, 0xf2, 0x14,
-	0x86, 0xe9, 0x0d, 0x38, 0xa6, 0xbb, 0xef, 0x82, 0x56, 0x17, 0xa7, 0xd7, 0xdf, 0x0d, 0xd0, 0x64,
+	0xda, 0x9b, 0x27, 0x8a, 0x44, 0xdb, 0x93, 0xff, 0xea, 0x9b, 0x16, 0x7e, 0xf2, 0x5a, 0x8c, 0x5d,
-	0x1f, 0xa3, 0x71, 0xfb, 0xe2, 0xaa, 0x8b, 0x7e, 0xbb, 0xea, 0xa2, 0x3f, 0xaf, 0xba, 0x68, 0xea,
+	0x61, 0xdf, 0xc1, 0x9e, 0xde, 0x9a, 0xa4, 0xfb, 0xfa, 0xe5, 0x1e, 0xf6, 0x76, 0xfe, 0xb7, 0x9e,
-	0x28, 0x6d, 0x3f, 0xf9, 0x37, 0x00, 0x00, 0xff, 0xff, 0x97, 0xc3, 0x70, 0xc2, 0xef, 0x07, 0x00,
+	0xce, 0xc0, 0xb7, 0x13, 0x70, 0x1b, 0xb4, 0xbe, 0x5c, 0xc3, 0xfe, 0x6e, 0x80, 0x71, 0xf6, 0xc8,
-	0x00,
+	0x21, 0x67, 0x9b, 0xa7, 0xe2, 0xb6, 0xd0, 0xea, 0xcc, 0x85, 0x6f, 0xf8, 0x3f, 0x70, 0x1e, 0x39,
+	0xa3, 0xce, 0x8b, 0xeb, 0xae, 0xf3, 0xe7, 0x75, 0xd7, 0xf9, 0xe7, 0xba, 0xeb, 0x4c, 0x7c, 0x5d,
+	0xce, 0x4f, 0xff, 0x0b, 0x00, 0x00, 0xff, 0xff, 0xc9, 0xc1, 0x1a, 0x81, 0x7c, 0x08, 0x00, 0x00,
 }

api/services/control/control.proto

@@ -13,6 +13,7 @@ service Control {
 	rpc DiskUsage(DiskUsageRequest) returns (DiskUsageResponse);
 	rpc Solve(SolveRequest) returns (SolveResponse);
 	rpc Status(StatusRequest) returns (stream StatusResponse);
+	rpc Session(stream BytesMessage) returns (stream BytesMessage);
 }
 
 message DiskUsageRequest {
@@ -34,6 +35,7 @@ message SolveRequest {
 	repeated bytes Definition = 2; // TODO: remove repeated
 	string Exporter = 3;
 	map<string, string> ExporterAttrs = 4;
+	string Session = 5;
 }
 
 message SolveResponse {
@@ -78,3 +80,7 @@ message VertexLog {
 	int64 stream = 3;
 	bytes msg = 4;
 }
+
+message BytesMessage {
+	bytes data = 1;
+}

client/client_test.go

@@ -106,6 +106,6 @@ func testBuildMultiMount(t *testing.T, address string) {
 	err = llb.WriteTo(dt, buf)
 	assert.Nil(t, err)
 
-	err = c.Solve(context.TODO(), buf, nil, "", nil)
+	err = c.Solve(context.TODO(), buf, nil, "", nil, "")
 	assert.Nil(t, err)
 }

client/llb/llb.go

@@ -78,6 +78,18 @@ func Scratch() *State {
 	return s
 }
 
+func Local(name string) *State {
+	return Source("local://" + name)
+}
+
+type LocalOption func(*source)
+
+func SessionID(id string) LocalOption {
+	return func(s *source) {
+		s.attrs[pb.AttrLocalSessionID] = id
+	}
+}
+
 type exec struct {
 	meta   Meta
 	mounts []*mount

client/local.go

@@ -0,0 +1,5 @@
+package client
+
+func getSharedKey(dir string) (string, error) {
+	return dir, nil // not implemented
+}

client/solve.go

@@ -5,15 +5,29 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"io"
+	"os"
+	"path/filepath"
+	"strings"
 	"time"
 
+	"github.com/Sirupsen/logrus"
 	controlapi "github.com/moby/buildkit/api/services/control"
 	"github.com/moby/buildkit/client/llb"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/session/filesync"
+	"github.com/moby/buildkit/session/grpchijack"
+	"github.com/moby/buildkit/solver/pb"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 )
 
-func (c *Client) Solve(ctx context.Context, r io.Reader, statusChan chan *SolveStatus, exporter string, exporterAttrs map[string]string) error {
+func (c *Client) Solve(ctx context.Context, r io.Reader, statusChan chan *SolveStatus, exporter string, exporterAttrs map[string]string, localDir string) error {
+	defer func() {
+		if statusChan != nil {
+			close(statusChan)
+		}
+	}()
+
 	def, err := llb.ReadFrom(r)
 	if err != nil {
 		return errors.Wrap(err, "failed to parse input")
@@ -23,10 +37,34 @@ func (c *Client) Solve(ctx context.Context, r io.Reader, statusChan chan *SolveS
 		return errors.New("invalid empty definition")
 	}
 
+	if err := validateLocals(def, localDir); err != nil {
+		return err
+	}
+
 	ref := generateID()
 	eg, ctx := errgroup.WithContext(ctx)
 
 	statusContext, cancelStatus := context.WithCancel(context.Background())
+	defer cancelStatus()
+
+	sharedKey, err := getSharedKey(localDir)
+	if err != nil {
+		return errors.Wrap(err, "failed to get build shared key")
+	}
+	s, err := session.NewSession(filepath.Base(localDir), sharedKey)
+	if err != nil {
+		return errors.Wrap(err, "failed to create session")
+	}
+
+	if localDir != "" {
+		_, dir, _ := parseLocalDir(localDir)
+		workdirProvider := filesync.NewFSSyncProvider(dir, nil)
+		s.Allow(workdirProvider)
+	}
+
+	eg.Go(func() error {
+		return s.Run(ctx, grpchijack.Dialer(c.controlClient()))
+	})
 
 	eg.Go(func() error {
 		defer func() { // make sure the Status ends cleanly on build errors
@@ -34,12 +72,15 @@ func (c *Client) Solve(ctx context.Context, r io.Reader, statusChan chan *SolveS
 				<-time.After(3 * time.Second)
 				cancelStatus()
 			}()
+			logrus.Debugf("stopping session")
+			s.Close()
 		}()
 		_, err = c.controlClient().Solve(ctx, &controlapi.SolveRequest{
 			Ref:           ref,
 			Definition:    def,
 			Exporter:      exporter,
 			ExporterAttrs: exporterAttrs,
+			Session:       s.UUID(),
 		})
 		if err != nil {
 			return errors.Wrap(err, "failed to solve")
@@ -100,12 +141,6 @@ func (c *Client) Solve(ctx context.Context, r io.Reader, statusChan chan *SolveS
 		}
 	})
 
-	defer func() {
-		if statusChan != nil {
-			close(statusChan)
-		}
-	}()
-
 	return eg.Wait()
 }
 
@@ -116,3 +151,44 @@ func generateID() string {
 	}
 	return hex.EncodeToString(b)
 }
+
+func validateLocals(defs [][]byte, localDir string) error {
+	k, _, err := parseLocalDir(localDir)
+	if err != nil {
+		return err
+	}
+	for _, dt := range defs {
+		var op pb.Op
+		if err := (&op).Unmarshal(dt); err != nil {
+			return errors.Wrap(err, "failed to parse llb proto op")
+		}
+		if src := op.GetSource(); src != nil {
+			if strings.HasPrefix(src.Identifier, "local://") { // TODO: just make a type property
+				name := strings.TrimPrefix(src.Identifier, "local://")
+				if name != k {
+					return errors.Errorf("local directory %s not enabled", name)
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func parseLocalDir(str string) (string, string, error) {
+	if str == "" {
+		return "", "", nil
+	}
+	parts := strings.SplitN(str, "=", 2)
+	if len(parts) != 2 {
+		return "", "", errors.Errorf("invalid local indentifier %q, need name=dir", str)
+	}
+	fi, err := os.Stat(parts[1])
+	if err != nil {
+		return "", "", errors.Wrapf(err, "could not find %s", parts[1])
+	}
+	if !fi.IsDir() {
+		return "", "", errors.Errorf("%s not a directory", parts[1])
+	}
+	return parts[0], parts[1], nil
+
+}

cmd/buildctl/build.go

@@ -33,6 +33,10 @@ var buildCommand = cli.Command{
 			Name:  "no-progress",
 			Usage: "Don't show interactive progress",
 		},
+		cli.StringFlag{
+			Name:  "local",
+			Usage: "Allow build access to the local directory",
+		},
 	},
 }
 
@@ -61,7 +65,7 @@ func build(clicontext *cli.Context) error {
 	}
 
 	eg.Go(func() error {
-		return c.Solve(ctx, os.Stdin, ch, clicontext.String("exporter"), exporterAttrs)
+		return c.Solve(ctx, os.Stdin, ch, clicontext.String("exporter"), exporterAttrs, clicontext.String("local"))
 	})
 
 	eg.Go(func() error {

control/control.go

@@ -1,11 +1,14 @@
 package control
 
 import (
+	"github.com/Sirupsen/logrus"
 	"github.com/containerd/containerd/snapshot"
 	controlapi "github.com/moby/buildkit/api/services/control"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/exporter"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/session/grpchijack"
 	"github.com/moby/buildkit/solver"
 	"github.com/moby/buildkit/source"
 	"github.com/moby/buildkit/worker"
@@ -22,6 +25,7 @@ type Opt struct {
 	SourceManager    *source.Manager
 	InstructionCache solver.InstructionCache
 	Exporters        map[string]exporter.Exporter
+	SessionManager   *session.Manager
 }
 
 type Controller struct { // TODO: ControlService
@@ -83,6 +87,8 @@ func (c *Controller) Solve(ctx context.Context, req *controlapi.SolveRequest) (*
 		}
 	}
 
+	ctx = session.NewContext(ctx, req.Session)
+
 	if err := c.solver.Solve(ctx, req.Ref, v, expi); err != nil {
 		return nil, err
 	}
@@ -147,3 +153,12 @@ func (c *Controller) Status(req *controlapi.StatusRequest, stream controlapi.Con
 
 	return eg.Wait()
 }
+
+func (c *Controller) Session(stream controlapi.Control_SessionServer) error {
+	logrus.Debugf("session started")
+	conn, opts := grpchijack.Hijack(stream)
+	defer conn.Close()
+	err := c.opt.SessionManager.HandleConn(stream.Context(), conn, opts)
+	logrus.Debugf("session finished: %v", err)
+	return err
+}

control/control_default.go

@@ -14,10 +14,12 @@ import (
 	"github.com/moby/buildkit/cache/metadata"
 	"github.com/moby/buildkit/exporter"
 	imageexporter "github.com/moby/buildkit/exporter/containerimage"
+	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/snapshot/blobmapping"
 	"github.com/moby/buildkit/source"
 	"github.com/moby/buildkit/source/containerimage"
 	"github.com/moby/buildkit/source/git"
+	"github.com/moby/buildkit/source/local"
 )
 
 const keyImageExporter = "image"
@@ -85,6 +87,20 @@ func defaultControllerOpts(root string, pd pullDeps) (*Opt, error) {
 
 	sm.Register(gs)
 
+	sessm, err := session.NewManager()
+	if err != nil {
+		return nil, err
+	}
+
+	ss, err := local.NewSource(local.Opt{
+		SessionManager: sessm,
+		CacheAccessor:  cm,
+	})
+	if err != nil {
+		return nil, err
+	}
+	sm.Register(ss)
+
 	exporters := map[string]exporter.Exporter{}
 
 	imageExporter, err := imageexporter.New(imageexporter.Opt{
@@ -105,5 +121,6 @@ func defaultControllerOpts(root string, pd pullDeps) (*Opt, error) {
 		SourceManager:    sm,
 		InstructionCache: ic,
 		Exporters:        exporters,
+		SessionManager:   sessm,
 	}, nil
 }

examples/buildkit3/buildkit.go

@@ -0,0 +1,114 @@
+package main
+
+import (
+	"flag"
+	"os"
+
+	"github.com/moby/buildkit/client/llb"
+	"github.com/moby/buildkit/util/system"
+)
+
+type buildOpt struct {
+	target     string
+	containerd string
+	runc       string
+	local      bool
+}
+
+func main() {
+	var opt buildOpt
+	flag.StringVar(&opt.target, "target", "containerd", "target (standalone, containerd)")
+	flag.StringVar(&opt.containerd, "containerd", "master", "containerd version")
+	flag.StringVar(&opt.runc, "runc", "v1.0.0-rc3", "runc version")
+	flag.BoolVar(&opt.local, "local", false, "use local buildkit source")
+	flag.Parse()
+
+	bk := buildkit(opt)
+	out := bk.Run(llb.Shlex("ls -l /bin")) // debug output
+
+	dt, err := out.Marshal()
+	if err != nil {
+		panic(err)
+	}
+	llb.WriteTo(dt, os.Stdout)
+}
+
+func goBuildBase() *llb.State {
+	goAlpine := llb.Image("docker.io/library/golang:1.8-alpine")
+	return goAlpine.
+		AddEnv("PATH", "/usr/local/go/bin:"+system.DefaultPathEnv).
+		AddEnv("GOPATH", "/go").
+		Run(llb.Shlex("apk add --no-cache g++ linux-headers make")).Root()
+}
+
+func goRepo(s *llb.State, repo string, src *llb.State) func(ro ...llb.RunOption) *llb.State {
+	dir := "/go/src/" + repo
+	return func(ro ...llb.RunOption) *llb.State {
+		es := s.Dir(dir).Run(ro...)
+		es.AddMount(dir, src)
+		return es.AddMount(dir+"/bin", llb.Scratch())
+	}
+}
+
+func runc(version string) *llb.State {
+	repo := "github.com/opencontainers/runc"
+	return goRepo(goBuildBase(), repo, llb.Git(repo, version))(
+		llb.Shlex("go build -o ./bin/runc ./"),
+	)
+}
+
+func containerd(version string) *llb.State {
+	repo := "github.com/containerd/containerd"
+	return goRepo(
+		goBuildBase().
+			Run(llb.Shlex("apk add --no-cache btrfs-progs-dev")).Root(),
+		repo, llb.Git(repo, version, llb.KeepGitDir()))(
+		llb.Shlex("make bin/containerd"),
+	)
+}
+
+func buildkit(opt buildOpt) *llb.State {
+	repo := "github.com/moby/buildkit"
+	src := llb.Git(repo, "master")
+	if opt.local {
+		src = llb.Local("buildkit-src")
+	}
+	run := goRepo(goBuildBase(), repo, src)
+
+	builddStandalone := run(llb.Shlex("go build -o ./bin/buildd-standalone -tags standalone ./cmd/buildd"))
+
+	builddContainerd := run(llb.Shlex("go build -o ./bin/buildd-containerd -tags containerd ./cmd/buildd"))
+
+	buildctl := run(llb.Shlex("go build -o ./bin/buildctl ./cmd/buildctl"))
+
+	r := llb.Image("docker.io/library/alpine:latest").With(
+		copyAll(buildctl, "/bin"),
+		copyAll(runc(opt.runc), "/bin"),
+	)
+
+	if opt.target == "containerd" {
+		return r.With(
+			copyAll(containerd(opt.containerd), "/bin"),
+			copyAll(builddContainerd, "/bin"))
+	}
+	return r.With(copyAll(builddStandalone, "/bin"))
+}
+
+func copyAll(src *llb.State, destPath string) llb.StateOption {
+	return copyFrom(src, "/.", destPath)
+}
+
+// copyFrom has similar semantics as `COPY --from`
+func copyFrom(src *llb.State, srcPath, destPath string) llb.StateOption {
+	return func(s *llb.State) *llb.State {
+		return copy(src, srcPath, s, destPath)
+	}
+}
+
+// copy copies files between 2 states using cp until there is no copyOp
+func copy(src *llb.State, srcPath string, dest *llb.State, destPath string) *llb.State {
+	cpImage := llb.Image("docker.io/library/alpine:latest")
+	cp := cpImage.Run(llb.Shlexf("cp -a /src%s /dest%s", srcPath, destPath))
+	cp.AddMount("/src", src)
+	return cp.AddMount("/dest", dest)
+}

session/context.go

@@ -0,0 +1,22 @@
+package session
+
+import "context"
+
+type contextKeyT string
+
+var contextKey = contextKeyT("buildkit/session-uuid")
+
+func NewContext(ctx context.Context, uuid string) context.Context {
+	if uuid != "" {
+		return context.WithValue(ctx, contextKey, uuid)
+	}
+	return ctx
+}
+
+func FromContext(ctx context.Context) string {
+	v := ctx.Value(contextKey)
+	if v == nil {
+		return ""
+	}
+	return v.(string)
+}

session/filesync/diffcopy.go

@@ -0,0 +1,30 @@
+package filesync
+
+import (
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/tonistiigi/fsutil"
+	"google.golang.org/grpc"
+)
+
+func sendDiffCopy(stream grpc.Stream, dir string, includes, excludes []string, progress progressCb) error {
+	return fsutil.Send(stream.Context(), stream, dir, &fsutil.WalkOpt{
+		ExcludePatterns: excludes,
+		IncludePaths:    includes, // TODO: rename IncludePatterns
+	}, 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)
+}

session/filesync/filesync.go

@@ -0,0 +1,186 @@
+package filesync
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/moby/buildkit/session"
+	"github.com/pkg/errors"
+	"github.com/tonistiigi/fsutil"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+const (
+	keyOverrideExcludes = "override-excludes"
+	keyIncludePatterns  = "include-patterns"
+)
+
+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[keyOverrideExcludes]) == 0 || opts[keyOverrideExcludes][0] != "true" {
+		excludes = sp.excludes
+	}
+	includes := opts[keyIncludePatterns]
+
+	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, includes, 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, includes, 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 {
+	IncludePatterns  []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[keyOverrideExcludes] = []string{"true"}
+	}
+
+	if opt.IncludePatterns != nil {
+		opts[keyIncludePatterns] = opt.IncludePatterns
+	}
+
+	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
+	default:
+		panic(fmt.Sprintf("invalid protocol: %q", pr.name))
+	}
+
+	return pr.recvFn(stream, opt.DestDir, opt.CacheUpdater)
+}

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,
+}

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;
+}

session/filesync/filesync_test.go

@@ -0,0 +1,71 @@
+package filesync
+
+import (
+	"context"
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/session/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sync/errgroup"
+)
+
+func TestFileSyncIncludePatterns(t *testing.T) {
+	tmpDir, err := ioutil.TempDir("", "fsynctest")
+	require.NoError(t, err)
+
+	destDir, err := ioutil.TempDir("", "fsynctest")
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(tmpDir, "foo"), []byte("content1"), 0600)
+	require.NoError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(tmpDir, "bar"), []byte("content2"), 0600)
+	require.NoError(t, err)
+
+	s, err := session.NewSession("foo", "bar")
+	require.NoError(t, err)
+
+	m, err := session.NewManager()
+	require.NoError(t, err)
+
+	fs := NewFSSyncProvider(tmpDir, nil)
+	s.Allow(fs)
+
+	dialer := session.Dialer(testutil.TestStream(testutil.Handler(m.HandleConn)))
+
+	g, ctx := errgroup.WithContext(context.Background())
+
+	g.Go(func() error {
+		return s.Run(ctx, dialer)
+	})
+
+	g.Go(func() (reterr error) {
+		c, err := m.Get(ctx, s.UUID())
+		if err != nil {
+			return err
+		}
+		if err := FSSync(ctx, c, FSSendRequestOpt{
+			DestDir:         destDir,
+			IncludePatterns: []string{"ba*"},
+		}); err != nil {
+			return err
+		}
+
+		_, err = ioutil.ReadFile(filepath.Join(destDir, "foo"))
+		assert.Error(t, err)
+
+		dt, err := ioutil.ReadFile(filepath.Join(destDir, "bar"))
+		if err != nil {
+			return err
+		}
+		assert.Equal(t, "content2", string(dt))
+		return s.Close()
+	})
+
+	err = g.Wait()
+	require.NoError(t, err)
+}

session/filesync/generate.go

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

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, includes, 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
+}

session/grpc.go

@@ -0,0 +1,62 @@
+package session
+
+import (
+	"net"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+	"golang.org/x/net/http2"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/health/grpc_health_v1"
+)
+
+func serve(ctx context.Context, grpcServer *grpc.Server, conn net.Conn) {
+	go func() {
+		<-ctx.Done()
+		conn.Close()
+	}()
+	logrus.Debugf("serving grpc connection")
+	(&http2.Server{}).ServeConn(conn, &http2.ServeConnOpts{Handler: grpcServer})
+}
+
+func grpcClientConn(ctx context.Context, conn net.Conn) (context.Context, *grpc.ClientConn, error) {
+	dialOpt := grpc.WithDialer(func(addr string, d time.Duration) (net.Conn, error) {
+		return conn, nil
+	})
+
+	cc, err := grpc.DialContext(ctx, "", dialOpt, grpc.WithInsecure())
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "failed to create grpc client")
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+	go monitorHealth(ctx, cc, cancel)
+
+	return ctx, cc, nil
+}
+
+func monitorHealth(ctx context.Context, cc *grpc.ClientConn, cancelConn func()) {
+	defer cancelConn()
+	defer cc.Close()
+
+	ticker := time.NewTicker(500 * time.Millisecond)
+	defer ticker.Stop()
+	healthClient := grpc_health_v1.NewHealthClient(cc)
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			<-ticker.C
+			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+			_, err := healthClient.Check(ctx, &grpc_health_v1.HealthCheckRequest{})
+			cancel()
+			if err != nil {
+				return
+			}
+		}
+	}
+}

session/grpchijack/dial.go

@@ -0,0 +1,123 @@
+package grpchijack
+
+import (
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	controlapi "github.com/moby/buildkit/api/services/control"
+	"github.com/moby/buildkit/session"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+var bufPool = sync.Pool{
+	New: func() interface{} {
+		return make([]byte, 32*1<<10)
+	},
+}
+
+func Dialer(api controlapi.ControlClient) session.Dialer {
+	return func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
+
+		meta = lowerHeaders(meta)
+
+		md := metadata.MD(meta)
+
+		ctx = metadata.NewContext(context.Background(), md)
+
+		stream, err := api.Session(ctx)
+		if err != nil {
+			return nil, err
+		}
+
+		return streamToConn(stream), nil
+	}
+}
+
+func streamToConn(stream grpc.Stream) net.Conn {
+	return &conn{stream: stream, buf: make([]byte, 32*1<<10)}
+}
+
+type conn struct {
+	stream  grpc.Stream
+	buf     []byte
+	lastBuf []byte
+}
+
+func (c *conn) Read(b []byte) (int, error) {
+	if c.lastBuf != nil {
+		n := copy(b, c.lastBuf)
+		c.lastBuf = c.lastBuf[n:]
+		if len(c.lastBuf) == 0 {
+			c.lastBuf = nil
+		}
+		return n, nil
+	}
+	m := new(controlapi.BytesMessage)
+	m.Data = c.buf
+
+	if err := c.stream.RecvMsg(m); err != nil {
+		return 0, err
+	}
+	c.buf = m.Data[:cap(m.Data)]
+
+	n := copy(b, m.Data)
+	if n < len(m.Data) {
+		c.lastBuf = m.Data[n:]
+	}
+
+	return n, nil
+}
+
+func (c *conn) Write(b []byte) (int, error) {
+	m := &controlapi.BytesMessage{Data: b}
+	if err := c.stream.SendMsg(m); err != nil {
+		return 0, err
+	}
+	return len(b), nil
+}
+
+func (s *conn) Close() error {
+	if cs, ok := s.stream.(grpc.ClientStream); ok {
+		return cs.CloseSend()
+	}
+	return nil
+}
+
+func (s *conn) LocalAddr() net.Addr {
+	return dummyAddr{}
+}
+func (s *conn) RemoteAddr() net.Addr {
+	return dummyAddr{}
+}
+func (s *conn) SetDeadline(t time.Time) error {
+	return nil
+}
+func (s *conn) SetReadDeadline(t time.Time) error {
+	return nil
+}
+func (s *conn) SetWriteDeadline(t time.Time) error {
+	return nil
+}
+
+type dummyAddr struct {
+}
+
+func (d dummyAddr) Network() string {
+	return "tcp"
+}
+
+func (d dummyAddr) String() string {
+	return "localhost"
+}
+
+func lowerHeaders(in map[string][]string) map[string][]string {
+	out := map[string][]string{}
+	for k := range in {
+		out[strings.ToLower(k)] = in[k]
+	}
+	return out
+}

session/grpchijack/hijack.go

@@ -0,0 +1,13 @@
+package grpchijack
+
+import (
+	"net"
+
+	controlapi "github.com/moby/buildkit/api/services/control"
+	"google.golang.org/grpc/metadata"
+)
+
+func Hijack(stream controlapi.Control_SessionServer) (net.Conn, map[string][]string) {
+	md, _ := metadata.FromContext(stream.Context())
+	return streamToConn(stream), md
+}

session/manager.go

@@ -0,0 +1,212 @@
+package session
+
+import (
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+)
+
+// Caller can invoke requests on the session
+type Caller interface {
+	Context() context.Context
+	Supports(method string) bool
+	Conn() *grpc.ClientConn
+	Name() string
+	SharedKey() string
+}
+
+type client struct {
+	Session
+	cc        *grpc.ClientConn
+	supported map[string]struct{}
+}
+
+// Manager is a controller for accessing currently active sessions
+type Manager struct {
+	sessions        map[string]*client
+	mu              sync.Mutex
+	updateCondition *sync.Cond
+}
+
+// NewManager returns a new Manager
+func NewManager() (*Manager, error) {
+	sm := &Manager{
+		sessions: make(map[string]*client),
+	}
+	sm.updateCondition = sync.NewCond(&sm.mu)
+	return sm, nil
+}
+
+// HandleHTTPRequest handles an incoming HTTP request
+func (sm *Manager) HandleHTTPRequest(ctx context.Context, w http.ResponseWriter, r *http.Request) error {
+	hijacker, ok := w.(http.Hijacker)
+	if !ok {
+		return errors.New("handler does not support hijack")
+	}
+
+	uuid := r.Header.Get(headerSessionUUID)
+
+	proto := r.Header.Get("Upgrade")
+
+	sm.mu.Lock()
+	if _, ok := sm.sessions[uuid]; ok {
+		sm.mu.Unlock()
+		return errors.Errorf("session %s already exists", uuid)
+	}
+
+	if proto == "" {
+		sm.mu.Unlock()
+		return errors.New("no upgrade proto in request")
+	}
+
+	if proto != "h2c" {
+		sm.mu.Unlock()
+		return errors.Errorf("protocol %s not supported", proto)
+	}
+
+	conn, _, err := hijacker.Hijack()
+	if err != nil {
+		sm.mu.Unlock()
+		return errors.Wrap(err, "failed to hijack connection")
+	}
+
+	resp := &http.Response{
+		StatusCode: http.StatusSwitchingProtocols,
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     http.Header{},
+	}
+	resp.Header.Set("Connection", "Upgrade")
+	resp.Header.Set("Upgrade", proto)
+
+	// set raw mode
+	conn.Write([]byte{})
+	resp.Write(conn)
+
+	return sm.handleConn(ctx, conn, r.Header)
+}
+
+// HandleConn handles an incoming raw connection
+func (sm *Manager) HandleConn(ctx context.Context, conn net.Conn, opts map[string][]string) error {
+	sm.mu.Lock()
+	return sm.handleConn(ctx, conn, opts)
+}
+
+// caller needs to take lock, this function will release it
+func (sm *Manager) handleConn(ctx context.Context, conn net.Conn, opts map[string][]string) error {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	opts = canonicalHeaders(opts)
+
+	h := http.Header(opts)
+	uuid := h.Get(headerSessionUUID)
+	name := h.Get(headerSessionName)
+	sharedKey := h.Get(headerSessionSharedKey)
+
+	ctx, cc, err := grpcClientConn(ctx, conn)
+	if err != nil {
+		sm.mu.Unlock()
+		return err
+	}
+
+	c := &client{
+		Session: Session{
+			uuid:      uuid,
+			name:      name,
+			sharedKey: sharedKey,
+			ctx:       ctx,
+			cancelCtx: cancel,
+			done:      make(chan struct{}),
+		},
+		cc:        cc,
+		supported: make(map[string]struct{}),
+	}
+
+	for _, m := range opts[headerSessionMethod] {
+		c.supported[strings.ToLower(m)] = struct{}{}
+	}
+	sm.sessions[uuid] = c
+	sm.updateCondition.Broadcast()
+	sm.mu.Unlock()
+
+	defer func() {
+		sm.mu.Lock()
+		delete(sm.sessions, uuid)
+		sm.mu.Unlock()
+	}()
+
+	<-c.ctx.Done()
+	conn.Close()
+	close(c.done)
+
+	return nil
+}
+
+// Get returns a session by UUID
+func (sm *Manager) Get(ctx context.Context, uuid string) (Caller, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	go func() {
+		select {
+		case <-ctx.Done():
+			sm.updateCondition.Broadcast()
+		}
+	}()
+
+	var c *client
+
+	sm.mu.Lock()
+	for {
+		select {
+		case <-ctx.Done():
+			sm.mu.Unlock()
+			return nil, errors.Wrapf(ctx.Err(), "no active session for %s", uuid)
+		default:
+		}
+		var ok bool
+		c, ok = sm.sessions[uuid]
+		if !ok || c.closed() {
+			sm.updateCondition.Wait()
+			continue
+		}
+		sm.mu.Unlock()
+		break
+	}
+
+	return c, nil
+}
+
+func (c *client) Context() context.Context {
+	return c.context()
+}
+
+func (c *client) Name() string {
+	return c.name
+}
+
+func (c *client) SharedKey() string {
+	return c.sharedKey
+}
+
+func (c *client) Supports(url string) bool {
+	_, ok := c.supported[strings.ToLower(url)]
+	return ok
+}
+func (c *client) Conn() *grpc.ClientConn {
+	return c.cc
+}
+
+func canonicalHeaders(in map[string][]string) map[string][]string {
+	out := map[string][]string{}
+	for k := range in {
+		out[http.CanonicalHeaderKey(k)] = in[k]
+	}
+	return out
+}

session/session.go

@@ -0,0 +1,118 @@
+package session
+
+import (
+	"net"
+
+	"github.com/docker/docker/pkg/stringid"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/health"
+	"google.golang.org/grpc/health/grpc_health_v1"
+)
+
+const (
+	headerSessionUUID      = "X-Docker-Expose-Session-Uuid"
+	headerSessionName      = "X-Docker-Expose-Session-Name"
+	headerSessionSharedKey = "X-Docker-Expose-Session-Sharedkey"
+	headerSessionMethod    = "X-Docker-Expose-Session-Grpc-Method"
+)
+
+// Dialer returns a connection that can be used by the session
+type Dialer func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error)
+
+// Attachable defines a feature that can be expsed on a session
+type Attachable interface {
+	Register(*grpc.Server)
+}
+
+// Session is a long running connection between client and a daemon
+type Session struct {
+	uuid       string
+	name       string
+	sharedKey  string
+	ctx        context.Context
+	cancelCtx  func()
+	done       chan struct{}
+	grpcServer *grpc.Server
+}
+
+// NewSession returns a new long running session
+func NewSession(name, sharedKey string) (*Session, error) {
+	uuid := stringid.GenerateRandomID()
+	s := &Session{
+		uuid:       uuid,
+		name:       name,
+		sharedKey:  sharedKey,
+		grpcServer: grpc.NewServer(),
+	}
+
+	grpc_health_v1.RegisterHealthServer(s.grpcServer, health.NewServer())
+
+	return s, nil
+}
+
+// Allow enable a given service to be reachable through the grpc session
+func (s *Session) Allow(a Attachable) {
+	a.Register(s.grpcServer)
+}
+
+// UUID returns unique identifier for the session
+func (s *Session) UUID() string {
+	return s.uuid
+}
+
+// Run activates the session
+func (s *Session) Run(ctx context.Context, dialer Dialer) error {
+	ctx, cancel := context.WithCancel(ctx)
+	s.cancelCtx = cancel
+	s.done = make(chan struct{})
+
+	defer cancel()
+	defer close(s.done)
+
+	meta := make(map[string][]string)
+	meta[headerSessionUUID] = []string{s.uuid}
+	meta[headerSessionName] = []string{s.name}
+	meta[headerSessionSharedKey] = []string{s.sharedKey}
+
+	for name, svc := range s.grpcServer.GetServiceInfo() {
+		for _, method := range svc.Methods {
+			meta[headerSessionMethod] = append(meta[headerSessionMethod], MethodURL(name, method.Name))
+		}
+	}
+	conn, err := dialer(ctx, "h2c", meta)
+	if err != nil {
+		return errors.Wrap(err, "failed to dial gRPC")
+	}
+	serve(ctx, s.grpcServer, conn)
+	return nil
+}
+
+// Close closes the session
+func (s *Session) Close() error {
+	if s.cancelCtx != nil && s.done != nil {
+		s.grpcServer.Stop()
+		s.cancelCtx()
+		<-s.done
+	}
+	return nil
+}
+
+func (s *Session) context() context.Context {
+	return s.ctx
+}
+
+func (s *Session) closed() bool {
+	select {
+	case <-s.context().Done():
+		return true
+	default:
+		return false
+	}
+}
+
+// MethodURL returns a gRPC method URL for service and method name
+func MethodURL(s, m string) string {
+	return "/" + s + "/" + m
+}

session/testutil/testutil.go

@@ -0,0 +1,70 @@
+package testutil
+
+import (
+	"io"
+	"net"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"golang.org/x/net/context"
+)
+
+// Handler is function called to handle incoming connection
+type Handler func(ctx context.Context, conn net.Conn, meta map[string][]string) error
+
+// Dialer is a function for dialing an outgoing connection
+type Dialer func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error)
+
+// TestStream creates an in memory session dialer for a handler function
+func TestStream(handler Handler) Dialer {
+	s1, s2 := sockPair()
+	return func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
+		go func() {
+			err := handler(context.TODO(), s1, meta)
+			if err != nil {
+				logrus.Error(err)
+			}
+			s1.Close()
+		}()
+		return s2, nil
+	}
+}
+
+func sockPair() (*sock, *sock) {
+	pr1, pw1 := io.Pipe()
+	pr2, pw2 := io.Pipe()
+	return &sock{pw1, pr2, pw1}, &sock{pw2, pr1, pw2}
+}
+
+type sock struct {
+	io.Writer
+	io.Reader
+	io.Closer
+}
+
+func (s *sock) LocalAddr() net.Addr {
+	return dummyAddr{}
+}
+func (s *sock) RemoteAddr() net.Addr {
+	return dummyAddr{}
+}
+func (s *sock) SetDeadline(t time.Time) error {
+	return nil
+}
+func (s *sock) SetReadDeadline(t time.Time) error {
+	return nil
+}
+func (s *sock) SetWriteDeadline(t time.Time) error {
+	return nil
+}
+
+type dummyAddr struct {
+}
+
+func (d dummyAddr) Network() string {
+	return "tcp"
+}
+
+func (d dummyAddr) String() string {
+	return "localhost"
+}

solver/pb/attr.go

@@ -1,3 +1,4 @@
 package pb
 
 const AttrKeepGitDir = "git.keepgitdir"
+const AttrLocalSessionID = "local.session"

solver/source.go

@@ -42,6 +42,14 @@ func (s *sourceOp) instance(ctx context.Context) (source.SourceInstance, error)
 			}
 		}
 	}
+	if id, ok := id.(*source.LocalIdentifier); ok {
+		for k, v := range s.op.Source.Attrs {
+			switch k {
+			case pb.AttrLocalSessionID:
+				id.SessionID = v
+			}
+		}
+	}
 	src, err := s.sm.Resolve(ctx, id)
 	if err != nil {
 		return nil, err

solver/vertex.go

@@ -83,6 +83,7 @@ func (v *vertex) notifyStarted(ctx context.Context) {
 	defer pw.Close()
 	now := time.Now()
 	v.clientVertex.Started = &now
+	v.clientVertex.Completed = nil
 	pw.Write(v.Digest().String(), v.clientVertex)
 }
 

source/identifier.go

@@ -15,6 +15,7 @@ var (
 const (
 	DockerImageScheme = "docker-image"
 	GitScheme         = "git"
+	LocalScheme       = "local"
 )
 
 type Identifier interface {
@@ -33,6 +34,8 @@ func FromString(s string) (Identifier, error) {
 		return NewImageIdentifier(parts[1])
 	case GitScheme:
 		return NewGitIdentifier(parts[1])
+	case LocalScheme:
+		return NewLocalIdentifier(parts[1])
 	default:
 		return nil, errors.Wrapf(errNotFound, "unknown schema %s", parts[0])
 	}
@@ -54,6 +57,19 @@ func NewImageIdentifier(str string) (*ImageIdentifier, error) {
 	return &ImageIdentifier{Reference: ref}, nil
 }
 
-func (i *ImageIdentifier) ID() string {
+func (_ *ImageIdentifier) ID() string {
 	return DockerImageScheme
 }
+
+type LocalIdentifier struct {
+	Name      string
+	SessionID string
+}
+
+func NewLocalIdentifier(str string) (*LocalIdentifier, error) {
+	return &LocalIdentifier{Name: str}, nil
+}
+
+func (_ *LocalIdentifier) ID() string {
+	return LocalScheme
+}

source/local/local.go

@@ -0,0 +1,138 @@
+package local
+
+import (
+	"time"
+
+	"github.com/moby/buildkit/cache"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/session/filesync"
+	"github.com/moby/buildkit/snapshot"
+	"github.com/moby/buildkit/source"
+	"github.com/pkg/errors"
+	"golang.org/x/net/context"
+)
+
+type Opt struct {
+	SessionManager *session.Manager
+	CacheAccessor  cache.Accessor
+}
+
+func NewSource(opt Opt) (source.Source, error) {
+	ls := &localSource{
+		sm: opt.SessionManager,
+		cm: opt.CacheAccessor,
+	}
+	return ls, nil
+}
+
+type localSource struct {
+	sm *session.Manager
+	cm cache.Accessor
+}
+
+func (ls *localSource) ID() string {
+	return source.LocalScheme
+}
+
+func (ls *localSource) Resolve(ctx context.Context, id source.Identifier) (source.SourceInstance, error) {
+	localIdentifier, ok := id.(*source.LocalIdentifier)
+	if !ok {
+		return nil, errors.Errorf("invalid local identifier %v", id)
+	}
+
+	return &localSourceHandler{
+		src:         *localIdentifier,
+		localSource: ls,
+	}, nil
+}
+
+type localSourceHandler struct {
+	src source.LocalIdentifier
+	*localSource
+}
+
+func (ls *localSourceHandler) CacheKey(ctx context.Context) (string, error) {
+	sessionID := ls.src.SessionID
+
+	if sessionID == "" {
+		uuid := session.FromContext(ctx)
+		if uuid == "" {
+			return "", errors.New("could not access local files without session")
+		}
+		sessionID = uuid
+	}
+
+	return "session:" + ls.src.Name + ":" + sessionID, nil
+}
+
+func (ls *localSourceHandler) Snapshot(ctx context.Context) (out cache.ImmutableRef, retErr error) {
+
+	uuid := session.FromContext(ctx)
+	if uuid == "" {
+		return nil, errors.New("could not access local files without session")
+	}
+
+	timeoutCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+
+	caller, err := ls.sm.Get(timeoutCtx, uuid)
+	if err != nil {
+		return nil, err
+	}
+
+	mutable, err := ls.cm.New(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if retErr != nil && mutable != nil {
+			s, err := mutable.Freeze()
+			if err == nil {
+				go s.Release(context.TODO())
+			}
+		}
+	}()
+
+	mount, err := mutable.Mount(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	lm := snapshot.LocalMounter(mount)
+
+	dest, err := lm.Mount()
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		if retErr != nil && lm != nil {
+			lm.Unmount()
+		}
+	}()
+
+	opt := filesync.FSSendRequestOpt{
+		IncludePatterns:  nil,
+		OverrideExcludes: false,
+		DestDir:          dest,
+		CacheUpdater:     nil,
+	}
+
+	if err := filesync.FSSync(ctx, caller, opt); err != nil {
+		return nil, err
+	}
+
+	if err := lm.Unmount(); err != nil {
+		return nil, err
+	}
+	lm = nil
+
+	snap, err := mutable.ReleaseAndCommit(ctx)
+	if err != nil {
+		return nil, err
+	}
+	mutable = nil
+
+	return snap, err
+}

vendor.conf

@@ -35,3 +35,6 @@ golang.org/x/time 8be79e1e0910c292df4e79c241bb7e8f7e725959
 github.com/BurntSushi/locker 392720b78f44e9d0249fcac6c43b111b47a370b8
 github.com/docker/docker 05c7c311390911daebcf5d9519dee813fc02a887
 github.com/pkg/profile 5b67d428864e92711fcbd2f8629456121a56d91f
+
+github.com/tonistiigi/fsutil 0ac4c11b053b9c5c7c47558f81f96c7100ce50fb
+github.com/stevvooe/continuity 86cec1535a968310e7532819f699ff2830ed7463

vendor/github.com/docker/docker/pkg/archive/README.md

@@ -0,0 +1 @@
+This code provides helper functions for dealing with archive files.

vendor/github.com/docker/docker/pkg/archive/archive_linux.go

@@ -0,0 +1,92 @@
+package archive
+
+import (
+	"archive/tar"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	if format == OverlayWhiteoutFormat {
+		return overlayWhiteoutConverter{}
+	}
+	return nil
+}
+
+type overlayWhiteoutConverter struct{}
+
+func (overlayWhiteoutConverter) ConvertWrite(hdr *tar.Header, path string, fi os.FileInfo) (wo *tar.Header, err error) {
+	// convert whiteouts to AUFS format
+	if fi.Mode()&os.ModeCharDevice != 0 && hdr.Devmajor == 0 && hdr.Devminor == 0 {
+		// we just rename the file and make it normal
+		dir, filename := filepath.Split(hdr.Name)
+		hdr.Name = filepath.Join(dir, WhiteoutPrefix+filename)
+		hdr.Mode = 0600
+		hdr.Typeflag = tar.TypeReg
+		hdr.Size = 0
+	}
+
+	if fi.Mode()&os.ModeDir != 0 {
+		// convert opaque dirs to AUFS format by writing an empty file with the prefix
+		opaque, err := system.Lgetxattr(path, "trusted.overlay.opaque")
+		if err != nil {
+			return nil, err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			if hdr.Xattrs != nil {
+				delete(hdr.Xattrs, "trusted.overlay.opaque")
+			}
+
+			// create a header for the whiteout file
+			// it should inherit some properties from the parent, but be a regular file
+			wo = &tar.Header{
+				Typeflag:   tar.TypeReg,
+				Mode:       hdr.Mode & int64(os.ModePerm),
+				Name:       filepath.Join(hdr.Name, WhiteoutOpaqueDir),
+				Size:       0,
+				Uid:        hdr.Uid,
+				Uname:      hdr.Uname,
+				Gid:        hdr.Gid,
+				Gname:      hdr.Gname,
+				AccessTime: hdr.AccessTime,
+				ChangeTime: hdr.ChangeTime,
+			}
+		}
+	}
+
+	return
+}
+
+func (overlayWhiteoutConverter) ConvertRead(hdr *tar.Header, path string) (bool, error) {
+	base := filepath.Base(path)
+	dir := filepath.Dir(path)
+
+	// if a directory is marked as opaque by the AUFS special file, we need to translate that to overlay
+	if base == WhiteoutOpaqueDir {
+		err := syscall.Setxattr(dir, "trusted.overlay.opaque", []byte{'y'}, 0)
+		// don't write the file itself
+		return false, err
+	}
+
+	// if a file was deleted and we are using overlay, we need to create a character device
+	if strings.HasPrefix(base, WhiteoutPrefix) {
+		originalBase := base[len(WhiteoutPrefix):]
+		originalPath := filepath.Join(dir, originalBase)
+
+		if err := syscall.Mknod(originalPath, syscall.S_IFCHR, 0); err != nil {
+			return false, err
+		}
+		if err := os.Chown(originalPath, hdr.Uid, hdr.Gid); err != nil {
+			return false, err
+		}
+
+		// don't write the file itself
+		return false, nil
+	}
+
+	return true, nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_other.go

@@ -0,0 +1,7 @@
+// +build !linux
+
+package archive
+
+func getWhiteoutConverter(format WhiteoutFormat) tarWhiteoutConverter {
+	return nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_unix.go

@@ -0,0 +1,121 @@
+// +build !windows
+
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return srcPath
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific. On Linux, we
+// can't use filepath.Join(srcPath,include) because this will clean away
+// a trailing "." or "/" which may be important.
+func getWalkRoot(srcPath string, include string) string {
+	return srcPath + string(filepath.Separator) + include
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	return p, nil // already unix-style
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	return perm // noop for unix as golang APIs provide perm bits correctly
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, name string, stat interface{}) (err error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if ok {
+		// Currently go does not fill in the major/minors
+		if s.Mode&syscall.S_IFBLK != 0 ||
+			s.Mode&syscall.S_IFCHR != 0 {
+			hdr.Devmajor = int64(major(uint64(s.Rdev)))
+			hdr.Devminor = int64(minor(uint64(s.Rdev)))
+		}
+	}
+
+	return
+}
+
+func getInodeFromStat(stat interface{}) (inode uint64, err error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if ok {
+		inode = uint64(s.Ino)
+	}
+
+	return
+}
+
+func getFileUIDGID(stat interface{}) (idtools.IDPair, error) {
+	s, ok := stat.(*syscall.Stat_t)
+
+	if !ok {
+		return idtools.IDPair{}, errors.New("cannot convert stat value to syscall.Stat_t")
+	}
+	return idtools.IDPair{UID: int(s.Uid), GID: int(s.Gid)}, nil
+}
+
+func major(device uint64) uint64 {
+	return (device >> 8) & 0xfff
+}
+
+func minor(device uint64) uint64 {
+	return (device & 0xff) | ((device >> 12) & 0xfff00)
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	if rsystem.RunningInUserNS() {
+		// cannot create a device if running in user namespace
+		return nil
+	}
+
+	mode := uint32(hdr.Mode & 07777)
+	switch hdr.Typeflag {
+	case tar.TypeBlock:
+		mode |= syscall.S_IFBLK
+	case tar.TypeChar:
+		mode |= syscall.S_IFCHR
+	case tar.TypeFifo:
+		mode |= syscall.S_IFIFO
+	}
+
+	return system.Mknod(path, mode, int(system.Mkdev(hdr.Devmajor, hdr.Devminor)))
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	if hdr.Typeflag == tar.TypeLink {
+		if fi, err := os.Lstat(hdr.Linkname); err == nil && (fi.Mode()&os.ModeSymlink == 0) {
+			if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+				return err
+			}
+		}
+	} else if hdr.Typeflag != tar.TypeSymlink {
+		if err := os.Chmod(path, hdrInfo.Mode()); err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/archive/archive_windows.go

@@ -0,0 +1,79 @@
+// +build windows
+
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// fixVolumePathPrefix does platform specific processing to ensure that if
+// the path being passed in is not in a volume path format, convert it to one.
+func fixVolumePathPrefix(srcPath string) string {
+	return longpath.AddPrefix(srcPath)
+}
+
+// getWalkRoot calculates the root path when performing a TarWithOptions.
+// We use a separate function as this is platform specific.
+func getWalkRoot(srcPath string, include string) string {
+	return filepath.Join(srcPath, include)
+}
+
+// CanonicalTarNameForPath returns platform-specific filepath
+// to canonical posix-style path for tar archival. p is relative
+// path.
+func CanonicalTarNameForPath(p string) (string, error) {
+	// windows: convert windows style relative path with backslashes
+	// into forward slashes. Since windows does not allow '/' or '\'
+	// in file names, it is mostly safe to replace however we must
+	// check just in case
+	if strings.Contains(p, "/") {
+		return "", fmt.Errorf("Windows path contains forward slash: %s", p)
+	}
+	return strings.Replace(p, string(os.PathSeparator), "/", -1), nil
+
+}
+
+// chmodTarEntry is used to adjust the file permissions used in tar header based
+// on the platform the archival is done.
+func chmodTarEntry(perm os.FileMode) os.FileMode {
+	//perm &= 0755 // this 0-ed out tar flags (like link, regular file, directory marker etc.)
+	permPart := perm & os.ModePerm
+	noPermPart := perm &^ os.ModePerm
+	// Add the x bit: make everything +x from windows
+	permPart |= 0111
+	permPart &= 0755
+
+	return noPermPart | permPart
+}
+
+func setHeaderForSpecialDevice(hdr *tar.Header, name string, stat interface{}) (err error) {
+	// do nothing. no notion of Rdev, Nlink in stat on Windows
+	return
+}
+
+func getInodeFromStat(stat interface{}) (inode uint64, err error) {
+	// do nothing. no notion of Inode in stat on Windows
+	return
+}
+
+// handleTarTypeBlockCharFifo is an OS-specific helper function used by
+// createTarFile to handle the following types of header: Block; Char; Fifo
+func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
+	return nil
+}
+
+func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
+	return nil
+}
+
+func getFileUIDGID(stat interface{}) (idtools.IDPair, error) {
+	// no notion of file ownership mapping yet on Windows
+	return idtools.IDPair{0, 0}, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes.go

@@ -0,0 +1,441 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/pools"
+	"github.com/docker/docker/pkg/system"
+)
+
+// ChangeType represents the change type.
+type ChangeType int
+
+const (
+	// ChangeModify represents the modify operation.
+	ChangeModify = iota
+	// ChangeAdd represents the add operation.
+	ChangeAdd
+	// ChangeDelete represents the delete operation.
+	ChangeDelete
+)
+
+func (c ChangeType) String() string {
+	switch c {
+	case ChangeModify:
+		return "C"
+	case ChangeAdd:
+		return "A"
+	case ChangeDelete:
+		return "D"
+	}
+	return ""
+}
+
+// Change represents a change, it wraps the change type and path.
+// It describes changes of the files in the path respect to the
+// parent layers. The change could be modify, add, delete.
+// This is used for layer diff.
+type Change struct {
+	Path string
+	Kind ChangeType
+}
+
+func (change *Change) String() string {
+	return fmt.Sprintf("%s %s", change.Kind, change.Path)
+}
+
+// for sort.Sort
+type changesByPath []Change
+
+func (c changesByPath) Less(i, j int) bool { return c[i].Path < c[j].Path }
+func (c changesByPath) Len() int           { return len(c) }
+func (c changesByPath) Swap(i, j int)      { c[j], c[i] = c[i], c[j] }
+
+// Gnu tar and the go tar writer don't have sub-second mtime
+// precision, which is problematic when we apply changes via tar
+// files, we handle this by comparing for exact times, *or* same
+// second count and either a or b having exactly 0 nanoseconds
+func sameFsTime(a, b time.Time) bool {
+	return a == b ||
+		(a.Unix() == b.Unix() &&
+			(a.Nanosecond() == 0 || b.Nanosecond() == 0))
+}
+
+func sameFsTimeSpec(a, b syscall.Timespec) bool {
+	return a.Sec == b.Sec &&
+		(a.Nsec == b.Nsec || a.Nsec == 0 || b.Nsec == 0)
+}
+
+// Changes walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func Changes(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, aufsDeletedFile, aufsMetadataSkip)
+}
+
+func aufsMetadataSkip(path string) (skip bool, err error) {
+	skip, err = filepath.Match(string(os.PathSeparator)+WhiteoutMetaPrefix+"*", path)
+	if err != nil {
+		skip = true
+	}
+	return
+}
+
+func aufsDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	f := filepath.Base(path)
+
+	// If there is a whiteout, then the file was removed
+	if strings.HasPrefix(f, WhiteoutPrefix) {
+		originalFile := f[len(WhiteoutPrefix):]
+		return filepath.Join(filepath.Dir(path), originalFile), nil
+	}
+
+	return "", nil
+}
+
+type skipChange func(string) (bool, error)
+type deleteChange func(string, string, os.FileInfo) (string, error)
+
+func changes(layers []string, rw string, dc deleteChange, sc skipChange) ([]Change, error) {
+	var (
+		changes     []Change
+		changedDirs = make(map[string]struct{})
+	)
+
+	err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		path, err = filepath.Rel(rw, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		path = filepath.Join(string(os.PathSeparator), path)
+
+		// Skip root
+		if path == string(os.PathSeparator) {
+			return nil
+		}
+
+		if sc != nil {
+			if skip, err := sc(path); skip {
+				return err
+			}
+		}
+
+		change := Change{
+			Path: path,
+		}
+
+		deletedFile, err := dc(rw, path, f)
+		if err != nil {
+			return err
+		}
+
+		// Find out what kind of modification happened
+		if deletedFile != "" {
+			change.Path = deletedFile
+			change.Kind = ChangeDelete
+		} else {
+			// Otherwise, the file was added
+			change.Kind = ChangeAdd
+
+			// ...Unless it already existed in a top layer, in which case, it's a modification
+			for _, layer := range layers {
+				stat, err := os.Stat(filepath.Join(layer, path))
+				if err != nil && !os.IsNotExist(err) {
+					return err
+				}
+				if err == nil {
+					// The file existed in the top layer, so that's a modification
+
+					// However, if it's a directory, maybe it wasn't actually modified.
+					// If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar
+					if stat.IsDir() && f.IsDir() {
+						if f.Size() == stat.Size() && f.Mode() == stat.Mode() && sameFsTime(f.ModTime(), stat.ModTime()) {
+							// Both directories are the same, don't record the change
+							return nil
+						}
+					}
+					change.Kind = ChangeModify
+					break
+				}
+			}
+		}
+
+		// If /foo/bar/file.txt is modified, then /foo/bar must be part of the changed files.
+		// This block is here to ensure the change is recorded even if the
+		// modify time, mode and size of the parent directory in the rw and ro layers are all equal.
+		// Check https://github.com/docker/docker/pull/13590 for details.
+		if f.IsDir() {
+			changedDirs[path] = struct{}{}
+		}
+		if change.Kind == ChangeAdd || change.Kind == ChangeDelete {
+			parent := filepath.Dir(path)
+			if _, ok := changedDirs[parent]; !ok && parent != "/" {
+				changes = append(changes, Change{Path: parent, Kind: ChangeModify})
+				changedDirs[parent] = struct{}{}
+			}
+		}
+
+		// Record change
+		changes = append(changes, change)
+		return nil
+	})
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	return changes, nil
+}
+
+// FileInfo describes the information of a file.
+type FileInfo struct {
+	parent     *FileInfo
+	name       string
+	stat       *system.StatT
+	children   map[string]*FileInfo
+	capability []byte
+	added      bool
+}
+
+// LookUp looks up the file information of a file.
+func (info *FileInfo) LookUp(path string) *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	parent := info
+	if path == string(os.PathSeparator) {
+		return info
+	}
+
+	pathElements := strings.Split(path, string(os.PathSeparator))
+	for _, elem := range pathElements {
+		if elem != "" {
+			child := parent.children[elem]
+			if child == nil {
+				return nil
+			}
+			parent = child
+		}
+	}
+	return parent
+}
+
+func (info *FileInfo) path() string {
+	if info.parent == nil {
+		// As this runs on the daemon side, file paths are OS specific.
+		return string(os.PathSeparator)
+	}
+	return filepath.Join(info.parent.path(), info.name)
+}
+
+func (info *FileInfo) addChanges(oldInfo *FileInfo, changes *[]Change) {
+
+	sizeAtEntry := len(*changes)
+
+	if oldInfo == nil {
+		// add
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeAdd,
+		}
+		*changes = append(*changes, change)
+		info.added = true
+	}
+
+	// We make a copy so we can modify it to detect additions
+	// also, we only recurse on the old dir if the new info is a directory
+	// otherwise any previous delete/change is considered recursive
+	oldChildren := make(map[string]*FileInfo)
+	if oldInfo != nil && info.isDir() {
+		for k, v := range oldInfo.children {
+			oldChildren[k] = v
+		}
+	}
+
+	for name, newChild := range info.children {
+		oldChild := oldChildren[name]
+		if oldChild != nil {
+			// change?
+			oldStat := oldChild.stat
+			newStat := newChild.stat
+			// Note: We can't compare inode or ctime or blocksize here, because these change
+			// when copying a file into a container. However, that is not generally a problem
+			// because any content change will change mtime, and any status change should
+			// be visible when actually comparing the stat fields. The only time this
+			// breaks down is if some code intentionally hides a change by setting
+			// back mtime
+			if statDifferent(oldStat, newStat) ||
+				!bytes.Equal(oldChild.capability, newChild.capability) {
+				change := Change{
+					Path: newChild.path(),
+					Kind: ChangeModify,
+				}
+				*changes = append(*changes, change)
+				newChild.added = true
+			}
+
+			// Remove from copy so we can detect deletions
+			delete(oldChildren, name)
+		}
+
+		newChild.addChanges(oldChild, changes)
+	}
+	for _, oldChild := range oldChildren {
+		// delete
+		change := Change{
+			Path: oldChild.path(),
+			Kind: ChangeDelete,
+		}
+		*changes = append(*changes, change)
+	}
+
+	// If there were changes inside this directory, we need to add it, even if the directory
+	// itself wasn't changed. This is needed to properly save and restore filesystem permissions.
+	// As this runs on the daemon side, file paths are OS specific.
+	if len(*changes) > sizeAtEntry && info.isDir() && !info.added && info.path() != string(os.PathSeparator) {
+		change := Change{
+			Path: info.path(),
+			Kind: ChangeModify,
+		}
+		// Let's insert the directory entry before the recently added entries located inside this dir
+		*changes = append(*changes, change) // just to resize the slice, will be overwritten
+		copy((*changes)[sizeAtEntry+1:], (*changes)[sizeAtEntry:])
+		(*changes)[sizeAtEntry] = change
+	}
+
+}
+
+// Changes add changes to file information.
+func (info *FileInfo) Changes(oldInfo *FileInfo) []Change {
+	var changes []Change
+
+	info.addChanges(oldInfo, &changes)
+
+	return changes
+}
+
+func newRootFileInfo() *FileInfo {
+	// As this runs on the daemon side, file paths are OS specific.
+	root := &FileInfo{
+		name:     string(os.PathSeparator),
+		children: make(map[string]*FileInfo),
+	}
+	return root
+}
+
+// ChangesDirs compares two directories and generates an array of Change objects describing the changes.
+// If oldDir is "", then all files in newDir will be Add-Changes.
+func ChangesDirs(newDir, oldDir string) ([]Change, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+	)
+	if oldDir == "" {
+		emptyDir, err := ioutil.TempDir("", "empty")
+		if err != nil {
+			return nil, err
+		}
+		defer os.Remove(emptyDir)
+		oldDir = emptyDir
+	}
+	oldRoot, newRoot, err := collectFileInfoForChanges(oldDir, newDir)
+	if err != nil {
+		return nil, err
+	}
+
+	return newRoot.Changes(oldRoot), nil
+}
+
+// ChangesSize calculates the size in bytes of the provided changes, based on newDir.
+func ChangesSize(newDir string, changes []Change) int64 {
+	var (
+		size int64
+		sf   = make(map[uint64]struct{})
+	)
+	for _, change := range changes {
+		if change.Kind == ChangeModify || change.Kind == ChangeAdd {
+			file := filepath.Join(newDir, change.Path)
+			fileInfo, err := os.Lstat(file)
+			if err != nil {
+				logrus.Errorf("Can not stat %q: %s", file, err)
+				continue
+			}
+
+			if fileInfo != nil && !fileInfo.IsDir() {
+				if hasHardlinks(fileInfo) {
+					inode := getIno(fileInfo)
+					if _, ok := sf[inode]; !ok {
+						size += fileInfo.Size()
+						sf[inode] = struct{}{}
+					}
+				} else {
+					size += fileInfo.Size()
+				}
+			}
+		}
+	}
+	return size
+}
+
+// ExportChanges produces an Archive from the provided changes, relative to dir.
+func ExportChanges(dir string, changes []Change, uidMaps, gidMaps []idtools.IDMap) (io.ReadCloser, error) {
+	reader, writer := io.Pipe()
+	go func() {
+		ta := newTarAppender(idtools.NewIDMappingsFromMaps(uidMaps, gidMaps), writer)
+
+		// this buffer is needed for the duration of this piped stream
+		defer pools.BufioWriter32KPool.Put(ta.Buffer)
+
+		sort.Sort(changesByPath(changes))
+
+		// In general we log errors here but ignore them because
+		// during e.g. a diff operation the container can continue
+		// mutating the filesystem and we can see transient errors
+		// from this
+		for _, change := range changes {
+			if change.Kind == ChangeDelete {
+				whiteOutDir := filepath.Dir(change.Path)
+				whiteOutBase := filepath.Base(change.Path)
+				whiteOut := filepath.Join(whiteOutDir, WhiteoutPrefix+whiteOutBase)
+				timestamp := time.Now()
+				hdr := &tar.Header{
+					Name:       whiteOut[1:],
+					Size:       0,
+					ModTime:    timestamp,
+					AccessTime: timestamp,
+					ChangeTime: timestamp,
+				}
+				if err := ta.TarWriter.WriteHeader(hdr); err != nil {
+					logrus.Debugf("Can't write whiteout header: %s", err)
+				}
+			} else {
+				path := filepath.Join(dir, change.Path)
+				if err := ta.addTarFile(path, change.Path[1:]); err != nil {
+					logrus.Debugf("Can't add file %s to tar: %s", path, err)
+				}
+			}
+		}
+
+		// Make sure to check the error on Close.
+		if err := ta.TarWriter.Close(); err != nil {
+			logrus.Debugf("Can't close layer: %s", err)
+		}
+		if err := writer.Close(); err != nil {
+			logrus.Debugf("failed close Changes writer: %s", err)
+		}
+	}()
+	return reader, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes_linux.go

@@ -0,0 +1,312 @@
+package archive
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"syscall"
+	"unsafe"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+// walker is used to implement collectFileInfoForChanges on linux. Where this
+// method in general returns the entire contents of two directory trees, we
+// optimize some FS calls out on linux. In particular, we take advantage of the
+// fact that getdents(2) returns the inode of each file in the directory being
+// walked, which, when walking two trees in parallel to generate a list of
+// changes, can be used to prune subtrees without ever having to lstat(2) them
+// directly. Eliminating stat calls in this way can save up to seconds on large
+// images.
+type walker struct {
+	dir1  string
+	dir2  string
+	root1 *FileInfo
+	root2 *FileInfo
+}
+
+// collectFileInfoForChanges returns a complete representation of the trees
+// rooted at dir1 and dir2, with one important exception: any subtree or
+// leaf where the inode and device numbers are an exact match between dir1
+// and dir2 will be pruned from the results. This method is *only* to be used
+// to generating a list of changes between the two directories, as it does not
+// reflect the full contents.
+func collectFileInfoForChanges(dir1, dir2 string) (*FileInfo, *FileInfo, error) {
+	w := &walker{
+		dir1:  dir1,
+		dir2:  dir2,
+		root1: newRootFileInfo(),
+		root2: newRootFileInfo(),
+	}
+
+	i1, err := os.Lstat(w.dir1)
+	if err != nil {
+		return nil, nil, err
+	}
+	i2, err := os.Lstat(w.dir2)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if err := w.walk("/", i1, i2); err != nil {
+		return nil, nil, err
+	}
+
+	return w.root1, w.root2, nil
+}
+
+// Given a FileInfo, its path info, and a reference to the root of the tree
+// being constructed, register this file with the tree.
+func walkchunk(path string, fi os.FileInfo, dir string, root *FileInfo) error {
+	if fi == nil {
+		return nil
+	}
+	parent := root.LookUp(filepath.Dir(path))
+	if parent == nil {
+		return fmt.Errorf("walkchunk: Unexpectedly no parent for %s", path)
+	}
+	info := &FileInfo{
+		name:     filepath.Base(path),
+		children: make(map[string]*FileInfo),
+		parent:   parent,
+	}
+	cpath := filepath.Join(dir, path)
+	stat, err := system.FromStatT(fi.Sys().(*syscall.Stat_t))
+	if err != nil {
+		return err
+	}
+	info.stat = stat
+	info.capability, _ = system.Lgetxattr(cpath, "security.capability") // lgetxattr(2): fs access
+	parent.children[info.name] = info
+	return nil
+}
+
+// Walk a subtree rooted at the same path in both trees being iterated. For
+// example, /docker/overlay/1234/a/b/c/d and /docker/overlay/8888/a/b/c/d
+func (w *walker) walk(path string, i1, i2 os.FileInfo) (err error) {
+	// Register these nodes with the return trees, unless we're still at the
+	// (already-created) roots:
+	if path != "/" {
+		if err := walkchunk(path, i1, w.dir1, w.root1); err != nil {
+			return err
+		}
+		if err := walkchunk(path, i2, w.dir2, w.root2); err != nil {
+			return err
+		}
+	}
+
+	is1Dir := i1 != nil && i1.IsDir()
+	is2Dir := i2 != nil && i2.IsDir()
+
+	sameDevice := false
+	if i1 != nil && i2 != nil {
+		si1 := i1.Sys().(*syscall.Stat_t)
+		si2 := i2.Sys().(*syscall.Stat_t)
+		if si1.Dev == si2.Dev {
+			sameDevice = true
+		}
+	}
+
+	// If these files are both non-existent, or leaves (non-dirs), we are done.
+	if !is1Dir && !is2Dir {
+		return nil
+	}
+
+	// Fetch the names of all the files contained in both directories being walked:
+	var names1, names2 []nameIno
+	if is1Dir {
+		names1, err = readdirnames(filepath.Join(w.dir1, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+	if is2Dir {
+		names2, err = readdirnames(filepath.Join(w.dir2, path)) // getdents(2): fs access
+		if err != nil {
+			return err
+		}
+	}
+
+	// We have lists of the files contained in both parallel directories, sorted
+	// in the same order. Walk them in parallel, generating a unique merged list
+	// of all items present in either or both directories.
+	var names []string
+	ix1 := 0
+	ix2 := 0
+
+	for {
+		if ix1 >= len(names1) {
+			break
+		}
+		if ix2 >= len(names2) {
+			break
+		}
+
+		ni1 := names1[ix1]
+		ni2 := names2[ix2]
+
+		switch bytes.Compare([]byte(ni1.name), []byte(ni2.name)) {
+		case -1: // ni1 < ni2 -- advance ni1
+			// we will not encounter ni1 in names2
+			names = append(names, ni1.name)
+			ix1++
+		case 0: // ni1 == ni2
+			if ni1.ino != ni2.ino || !sameDevice {
+				names = append(names, ni1.name)
+			}
+			ix1++
+			ix2++
+		case 1: // ni1 > ni2 -- advance ni2
+			// we will not encounter ni2 in names1
+			names = append(names, ni2.name)
+			ix2++
+		}
+	}
+	for ix1 < len(names1) {
+		names = append(names, names1[ix1].name)
+		ix1++
+	}
+	for ix2 < len(names2) {
+		names = append(names, names2[ix2].name)
+		ix2++
+	}
+
+	// For each of the names present in either or both of the directories being
+	// iterated, stat the name under each root, and recurse the pair of them:
+	for _, name := range names {
+		fname := filepath.Join(path, name)
+		var cInfo1, cInfo2 os.FileInfo
+		if is1Dir {
+			cInfo1, err = os.Lstat(filepath.Join(w.dir1, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if is2Dir {
+			cInfo2, err = os.Lstat(filepath.Join(w.dir2, fname)) // lstat(2): fs access
+			if err != nil && !os.IsNotExist(err) {
+				return err
+			}
+		}
+		if err = w.walk(fname, cInfo1, cInfo2); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// {name,inode} pairs used to support the early-pruning logic of the walker type
+type nameIno struct {
+	name string
+	ino  uint64
+}
+
+type nameInoSlice []nameIno
+
+func (s nameInoSlice) Len() int           { return len(s) }
+func (s nameInoSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s nameInoSlice) Less(i, j int) bool { return s[i].name < s[j].name }
+
+// readdirnames is a hacked-apart version of the Go stdlib code, exposing inode
+// numbers further up the stack when reading directory contents. Unlike
+// os.Readdirnames, which returns a list of filenames, this function returns a
+// list of {filename,inode} pairs.
+func readdirnames(dirname string) (names []nameIno, err error) {
+	var (
+		size = 100
+		buf  = make([]byte, 4096)
+		nbuf int
+		bufp int
+		nb   int
+	)
+
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	names = make([]nameIno, 0, size) // Empty with room to grow.
+	for {
+		// Refill the buffer if necessary
+		if bufp >= nbuf {
+			bufp = 0
+			nbuf, err = syscall.ReadDirent(int(f.Fd()), buf) // getdents on linux
+			if nbuf < 0 {
+				nbuf = 0
+			}
+			if err != nil {
+				return nil, os.NewSyscallError("readdirent", err)
+			}
+			if nbuf <= 0 {
+				break // EOF
+			}
+		}
+
+		// Drain the buffer
+		nb, names = parseDirent(buf[bufp:nbuf], names)
+		bufp += nb
+	}
+
+	sl := nameInoSlice(names)
+	sort.Sort(sl)
+	return sl, nil
+}
+
+// parseDirent is a minor modification of syscall.ParseDirent (linux version)
+// which returns {name,inode} pairs instead of just names.
+func parseDirent(buf []byte, names []nameIno) (consumed int, newnames []nameIno) {
+	origlen := len(buf)
+	for len(buf) > 0 {
+		dirent := (*syscall.Dirent)(unsafe.Pointer(&buf[0]))
+		buf = buf[dirent.Reclen:]
+		if dirent.Ino == 0 { // File absent in directory.
+			continue
+		}
+		bytes := (*[10000]byte)(unsafe.Pointer(&dirent.Name[0]))
+		var name = string(bytes[0:clen(bytes[:])])
+		if name == "." || name == ".." { // Useless names
+			continue
+		}
+		names = append(names, nameIno{name, dirent.Ino})
+	}
+	return origlen - len(buf), names
+}
+
+func clen(n []byte) int {
+	for i := 0; i < len(n); i++ {
+		if n[i] == 0 {
+			return i
+		}
+	}
+	return len(n)
+}
+
+// OverlayChanges walks the path rw and determines changes for the files in the path,
+// with respect to the parent layers
+func OverlayChanges(layers []string, rw string) ([]Change, error) {
+	return changes(layers, rw, overlayDeletedFile, nil)
+}
+
+func overlayDeletedFile(root, path string, fi os.FileInfo) (string, error) {
+	if fi.Mode()&os.ModeCharDevice != 0 {
+		s := fi.Sys().(*syscall.Stat_t)
+		if major(uint64(s.Rdev)) == 0 && minor(uint64(s.Rdev)) == 0 {
+			return path, nil
+		}
+	}
+	if fi.Mode()&os.ModeDir != 0 {
+		opaque, err := system.Lgetxattr(filepath.Join(root, path), "trusted.overlay.opaque")
+		if err != nil {
+			return "", err
+		}
+		if len(opaque) == 1 && opaque[0] == 'y' {
+			return path, nil
+		}
+	}
+
+	return "", nil
+
+}

vendor/github.com/docker/docker/pkg/archive/changes_other.go

@@ -0,0 +1,97 @@
+// +build !linux
+
+package archive
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func collectFileInfoForChanges(oldDir, newDir string) (*FileInfo, *FileInfo, error) {
+	var (
+		oldRoot, newRoot *FileInfo
+		err1, err2       error
+		errs             = make(chan error, 2)
+	)
+	go func() {
+		oldRoot, err1 = collectFileInfo(oldDir)
+		errs <- err1
+	}()
+	go func() {
+		newRoot, err2 = collectFileInfo(newDir)
+		errs <- err2
+	}()
+
+	// block until both routines have returned
+	for i := 0; i < 2; i++ {
+		if err := <-errs; err != nil {
+			return nil, nil, err
+		}
+	}
+
+	return oldRoot, newRoot, nil
+}
+
+func collectFileInfo(sourceDir string) (*FileInfo, error) {
+	root := newRootFileInfo()
+
+	err := filepath.Walk(sourceDir, func(path string, f os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Rebase path
+		relPath, err := filepath.Rel(sourceDir, path)
+		if err != nil {
+			return err
+		}
+
+		// As this runs on the daemon side, file paths are OS specific.
+		relPath = filepath.Join(string(os.PathSeparator), relPath)
+
+		// See https://github.com/golang/go/issues/9168 - bug in filepath.Join.
+		// Temporary workaround. If the returned path starts with two backslashes,
+		// trim it down to a single backslash. Only relevant on Windows.
+		if runtime.GOOS == "windows" {
+			if strings.HasPrefix(relPath, `\\`) {
+				relPath = relPath[1:]
+			}
+		}
+
+		if relPath == string(os.PathSeparator) {
+			return nil
+		}
+
+		parent := root.LookUp(filepath.Dir(relPath))
+		if parent == nil {
+			return fmt.Errorf("collectFileInfo: Unexpectedly no parent for %s", relPath)
+		}
+
+		info := &FileInfo{
+			name:     filepath.Base(relPath),
+			children: make(map[string]*FileInfo),
+			parent:   parent,
+		}
+
+		s, err := system.Lstat(path)
+		if err != nil {
+			return err
+		}
+		info.stat = s
+
+		info.capability, _ = system.Lgetxattr(path, "security.capability")
+
+		parent.children[info.name] = info
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return root, nil
+}

vendor/github.com/docker/docker/pkg/archive/changes_unix.go

@@ -0,0 +1,36 @@
+// +build !windows
+
+package archive
+
+import (
+	"os"
+	"syscall"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.Mode() != newStat.Mode() ||
+		oldStat.UID() != newStat.UID() ||
+		oldStat.GID() != newStat.GID() ||
+		oldStat.Rdev() != newStat.Rdev() ||
+		// Don't look at size for dirs, its not a good measure of change
+		(oldStat.Mode()&syscall.S_IFDIR != syscall.S_IFDIR &&
+			(!sameFsTimeSpec(oldStat.Mtim(), newStat.Mtim()) || (oldStat.Size() != newStat.Size()))) {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.Mode()&syscall.S_IFDIR != 0
+}
+
+func getIno(fi os.FileInfo) uint64 {
+	return uint64(fi.Sys().(*syscall.Stat_t).Ino)
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return fi.Sys().(*syscall.Stat_t).Nlink > 1
+}

vendor/github.com/docker/docker/pkg/archive/changes_windows.go

@@ -0,0 +1,30 @@
+package archive
+
+import (
+	"os"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {
+
+	// Don't look at size for dirs, its not a good measure of change
+	if oldStat.Mtim() != newStat.Mtim() ||
+		oldStat.Mode() != newStat.Mode() ||
+		oldStat.Size() != newStat.Size() && !oldStat.Mode().IsDir() {
+		return true
+	}
+	return false
+}
+
+func (info *FileInfo) isDir() bool {
+	return info.parent == nil || info.stat.Mode().IsDir()
+}
+
+func getIno(fi os.FileInfo) (inode uint64) {
+	return
+}
+
+func hasHardlinks(fi os.FileInfo) bool {
+	return false
+}

vendor/github.com/docker/docker/pkg/archive/copy.go

@@ -0,0 +1,458 @@
+package archive
+
+import (
+	"archive/tar"
+	"errors"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/system"
+)
+
+// Errors used or returned by this file.
+var (
+	ErrNotDirectory      = errors.New("not a directory")
+	ErrDirNotExists      = errors.New("no such directory")
+	ErrCannotCopyDir     = errors.New("cannot copy directory")
+	ErrInvalidCopySource = errors.New("invalid copy source content")
+)
+
+// PreserveTrailingDotOrSeparator returns the given cleaned path (after
+// processing using any utility functions from the path or filepath stdlib
+// packages) and appends a trailing `/.` or `/` if its corresponding  original
+// path (from before being processed by utility functions from the path or
+// filepath stdlib packages) ends with a trailing `/.` or `/`. If the cleaned
+// path already ends in a `.` path segment, then another is not added. If the
+// clean path already ends in a path separator, then another is not added.
+func PreserveTrailingDotOrSeparator(cleanedPath, originalPath string) string {
+	// Ensure paths are in platform semantics
+	cleanedPath = normalizePath(cleanedPath)
+	originalPath = normalizePath(originalPath)
+
+	if !specifiesCurrentDir(cleanedPath) && specifiesCurrentDir(originalPath) {
+		if !hasTrailingPathSeparator(cleanedPath) {
+			// Add a separator if it doesn't already end with one (a cleaned
+			// path would only end in a separator if it is the root).
+			cleanedPath += string(filepath.Separator)
+		}
+		cleanedPath += "."
+	}
+
+	if !hasTrailingPathSeparator(cleanedPath) && hasTrailingPathSeparator(originalPath) {
+		cleanedPath += string(filepath.Separator)
+	}
+
+	return cleanedPath
+}
+
+// assertsDirectory returns whether the given path is
+// asserted to be a directory, i.e., the path ends with
+// a trailing '/' or `/.`, assuming a path separator of `/`.
+func assertsDirectory(path string) bool {
+	return hasTrailingPathSeparator(path) || specifiesCurrentDir(path)
+}
+
+// hasTrailingPathSeparator returns whether the given
+// path ends with the system's path separator character.
+func hasTrailingPathSeparator(path string) bool {
+	return len(path) > 0 && os.IsPathSeparator(path[len(path)-1])
+}
+
+// specifiesCurrentDir returns whether the given path specifies
+// a "current directory", i.e., the last path segment is `.`.
+func specifiesCurrentDir(path string) bool {
+	return filepath.Base(path) == "."
+}
+
+// SplitPathDirEntry splits the given path between its directory name and its
+// basename by first cleaning the path but preserves a trailing "." if the
+// original path specified the current directory.
+func SplitPathDirEntry(path string) (dir, base string) {
+	cleanedPath := filepath.Clean(normalizePath(path))
+
+	if specifiesCurrentDir(path) {
+		cleanedPath += string(filepath.Separator) + "."
+	}
+
+	return filepath.Dir(cleanedPath), filepath.Base(cleanedPath)
+}
+
+// TarResource archives the resource described by the given CopyInfo to a Tar
+// archive. A non-nil error is returned if sourcePath does not exist or is
+// asserted to be a directory but exists as another type of file.
+//
+// This function acts as a convenient wrapper around TarWithOptions, which
+// requires a directory as the source path. TarResource accepts either a
+// directory or a file path and correctly sets the Tar options.
+func TarResource(sourceInfo CopyInfo) (content io.ReadCloser, err error) {
+	return TarResourceRebase(sourceInfo.Path, sourceInfo.RebaseName)
+}
+
+// TarResourceRebase is like TarResource but renames the first path element of
+// items in the resulting tar archive to match the given rebaseName if not "".
+func TarResourceRebase(sourcePath, rebaseName string) (content io.ReadCloser, err error) {
+	sourcePath = normalizePath(sourcePath)
+	if _, err = os.Lstat(sourcePath); err != nil {
+		// Catches the case where the source does not exist or is not a
+		// directory if asserted to be a directory, as this also causes an
+		// error.
+		return
+	}
+
+	// Separate the source path between its directory and
+	// the entry in that directory which we are archiving.
+	sourceDir, sourceBase := SplitPathDirEntry(sourcePath)
+
+	filter := []string{sourceBase}
+
+	logrus.Debugf("copying %q from %q", sourceBase, sourceDir)
+
+	return TarWithOptions(sourceDir, &TarOptions{
+		Compression:      Uncompressed,
+		IncludeFiles:     filter,
+		IncludeSourceDir: true,
+		RebaseNames: map[string]string{
+			sourceBase: rebaseName,
+		},
+	})
+}
+
+// CopyInfo holds basic info about the source
+// or destination path of a copy operation.
+type CopyInfo struct {
+	Path       string
+	Exists     bool
+	IsDir      bool
+	RebaseName string
+}
+
+// CopyInfoSourcePath stats the given path to create a CopyInfo
+// struct representing that resource for the source of an archive copy
+// operation. The given path should be an absolute local path. A source path
+// has all symlinks evaluated that appear before the last path separator ("/"
+// on Unix). As it is to be a copy source, the path must exist.
+func CopyInfoSourcePath(path string, followLink bool) (CopyInfo, error) {
+	// normalize the file path and then evaluate the symbol link
+	// we will use the target file instead of the symbol link if
+	// followLink is set
+	path = normalizePath(path)
+
+	resolvedPath, rebaseName, err := ResolveHostSourcePath(path, followLink)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	stat, err := os.Lstat(resolvedPath)
+	if err != nil {
+		return CopyInfo{}, err
+	}
+
+	return CopyInfo{
+		Path:       resolvedPath,
+		Exists:     true,
+		IsDir:      stat.IsDir(),
+		RebaseName: rebaseName,
+	}, nil
+}
+
+// CopyInfoDestinationPath stats the given path to create a CopyInfo
+// struct representing that resource for the destination of an archive copy
+// operation. The given path should be an absolute local path.
+func CopyInfoDestinationPath(path string) (info CopyInfo, err error) {
+	maxSymlinkIter := 10 // filepath.EvalSymlinks uses 255, but 10 already seems like a lot.
+	path = normalizePath(path)
+	originalPath := path
+
+	stat, err := os.Lstat(path)
+
+	if err == nil && stat.Mode()&os.ModeSymlink == 0 {
+		// The path exists and is not a symlink.
+		return CopyInfo{
+			Path:   path,
+			Exists: true,
+			IsDir:  stat.IsDir(),
+		}, nil
+	}
+
+	// While the path is a symlink.
+	for n := 0; err == nil && stat.Mode()&os.ModeSymlink != 0; n++ {
+		if n > maxSymlinkIter {
+			// Don't follow symlinks more than this arbitrary number of times.
+			return CopyInfo{}, errors.New("too many symlinks in " + originalPath)
+		}
+
+		// The path is a symbolic link. We need to evaluate it so that the
+		// destination of the copy operation is the link target and not the
+		// link itself. This is notably different than CopyInfoSourcePath which
+		// only evaluates symlinks before the last appearing path separator.
+		// Also note that it is okay if the last path element is a broken
+		// symlink as the copy operation should create the target.
+		var linkTarget string
+
+		linkTarget, err = os.Readlink(path)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+
+		if !system.IsAbs(linkTarget) {
+			// Join with the parent directory.
+			dstParent, _ := SplitPathDirEntry(path)
+			linkTarget = filepath.Join(dstParent, linkTarget)
+		}
+
+		path = linkTarget
+		stat, err = os.Lstat(path)
+	}
+
+	if err != nil {
+		// It's okay if the destination path doesn't exist. We can still
+		// continue the copy operation if the parent directory exists.
+		if !os.IsNotExist(err) {
+			return CopyInfo{}, err
+		}
+
+		// Ensure destination parent dir exists.
+		dstParent, _ := SplitPathDirEntry(path)
+
+		parentDirStat, err := os.Lstat(dstParent)
+		if err != nil {
+			return CopyInfo{}, err
+		}
+		if !parentDirStat.IsDir() {
+			return CopyInfo{}, ErrNotDirectory
+		}
+
+		return CopyInfo{Path: path}, nil
+	}
+
+	// The path exists after resolving symlinks.
+	return CopyInfo{
+		Path:   path,
+		Exists: true,
+		IsDir:  stat.IsDir(),
+	}, nil
+}
+
+// PrepareArchiveCopy prepares the given srcContent archive, which should
+// contain the archived resource described by srcInfo, to the destination
+// described by dstInfo. Returns the possibly modified content archive along
+// with the path to the destination directory which it should be extracted to.
+func PrepareArchiveCopy(srcContent io.Reader, srcInfo, dstInfo CopyInfo) (dstDir string, content io.ReadCloser, err error) {
+	// Ensure in platform semantics
+	srcInfo.Path = normalizePath(srcInfo.Path)
+	dstInfo.Path = normalizePath(dstInfo.Path)
+
+	// Separate the destination path between its directory and base
+	// components in case the source archive contents need to be rebased.
+	dstDir, dstBase := SplitPathDirEntry(dstInfo.Path)
+	_, srcBase := SplitPathDirEntry(srcInfo.Path)
+
+	switch {
+	case dstInfo.Exists && dstInfo.IsDir:
+		// The destination exists as a directory. No alteration
+		// to srcContent is needed as its contents can be
+		// simply extracted to the destination directory.
+		return dstInfo.Path, ioutil.NopCloser(srcContent), nil
+	case dstInfo.Exists && srcInfo.IsDir:
+		// The destination exists as some type of file and the source
+		// content is a directory. This is an error condition since
+		// you cannot copy a directory to an existing file location.
+		return "", nil, ErrCannotCopyDir
+	case dstInfo.Exists:
+		// The destination exists as some type of file and the source content
+		// is also a file. The source content entry will have to be renamed to
+		// have a basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case srcInfo.IsDir:
+		// The destination does not exist and the source content is an archive
+		// of a directory. The archive should be extracted to the parent of
+		// the destination path instead, and when it is, the directory that is
+		// created as a result should take the name of the destination path.
+		// The source content entries will have to be renamed to have a
+		// basename which matches the destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	case assertsDirectory(dstInfo.Path):
+		// The destination does not exist and is asserted to be created as a
+		// directory, but the source content is not a directory. This is an
+		// error condition since you cannot create a directory from a file
+		// source.
+		return "", nil, ErrDirNotExists
+	default:
+		// The last remaining case is when the destination does not exist, is
+		// not asserted to be a directory, and the source content is not an
+		// archive of a directory. It this case, the destination file will need
+		// to be created when the archive is extracted and the source content
+		// entry will have to be renamed to have a basename which matches the
+		// destination path's basename.
+		if len(srcInfo.RebaseName) != 0 {
+			srcBase = srcInfo.RebaseName
+		}
+		return dstDir, RebaseArchiveEntries(srcContent, srcBase, dstBase), nil
+	}
+
+}
+
+// RebaseArchiveEntries rewrites the given srcContent archive replacing
+// an occurrence of oldBase with newBase at the beginning of entry names.
+func RebaseArchiveEntries(srcContent io.Reader, oldBase, newBase string) io.ReadCloser {
+	if oldBase == string(os.PathSeparator) {
+		// If oldBase specifies the root directory, use an empty string as
+		// oldBase instead so that newBase doesn't replace the path separator
+		// that all paths will start with.
+		oldBase = ""
+	}
+
+	rebased, w := io.Pipe()
+
+	go func() {
+		srcTar := tar.NewReader(srcContent)
+		rebasedTar := tar.NewWriter(w)
+
+		for {
+			hdr, err := srcTar.Next()
+			if err == io.EOF {
+				// Signals end of archive.
+				rebasedTar.Close()
+				w.Close()
+				return
+			}
+			if err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			hdr.Name = strings.Replace(hdr.Name, oldBase, newBase, 1)
+
+			if err = rebasedTar.WriteHeader(hdr); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			if _, err = io.Copy(rebasedTar, srcTar); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+		}
+	}()
+
+	return rebased
+}
+
+// CopyResource performs an archive copy from the given source path to the
+// given destination path. The source path MUST exist and the destination
+// path's parent directory must exist.
+func CopyResource(srcPath, dstPath string, followLink bool) error {
+	var (
+		srcInfo CopyInfo
+		err     error
+	)
+
+	// Ensure in platform semantics
+	srcPath = normalizePath(srcPath)
+	dstPath = normalizePath(dstPath)
+
+	// Clean the source and destination paths.
+	srcPath = PreserveTrailingDotOrSeparator(filepath.Clean(srcPath), srcPath)
+	dstPath = PreserveTrailingDotOrSeparator(filepath.Clean(dstPath), dstPath)
+
+	if srcInfo, err = CopyInfoSourcePath(srcPath, followLink); err != nil {
+		return err
+	}
+
+	content, err := TarResource(srcInfo)
+	if err != nil {
+		return err
+	}
+	defer content.Close()
+
+	return CopyTo(content, srcInfo, dstPath)
+}
+
+// CopyTo handles extracting the given content whose
+// entries should be sourced from srcInfo to dstPath.
+func CopyTo(content io.Reader, srcInfo CopyInfo, dstPath string) error {
+	// The destination path need not exist, but CopyInfoDestinationPath will
+	// ensure that at least the parent directory exists.
+	dstInfo, err := CopyInfoDestinationPath(normalizePath(dstPath))
+	if err != nil {
+		return err
+	}
+
+	dstDir, copyArchive, err := PrepareArchiveCopy(content, srcInfo, dstInfo)
+	if err != nil {
+		return err
+	}
+	defer copyArchive.Close()
+
+	options := &TarOptions{
+		NoLchown:             true,
+		NoOverwriteDirNonDir: true,
+	}
+
+	return Untar(copyArchive, dstDir, options)
+}
+
+// ResolveHostSourcePath decides real path need to be copied with parameters such as
+// whether to follow symbol link or not, if followLink is true, resolvedPath will return
+// link target of any symbol link file, else it will only resolve symlink of directory
+// but return symbol link file itself without resolving.
+func ResolveHostSourcePath(path string, followLink bool) (resolvedPath, rebaseName string, err error) {
+	if followLink {
+		resolvedPath, err = filepath.EvalSymlinks(path)
+		if err != nil {
+			return
+		}
+
+		resolvedPath, rebaseName = GetRebaseName(path, resolvedPath)
+	} else {
+		dirPath, basePath := filepath.Split(path)
+
+		// if not follow symbol link, then resolve symbol link of parent dir
+		var resolvedDirPath string
+		resolvedDirPath, err = filepath.EvalSymlinks(dirPath)
+		if err != nil {
+			return
+		}
+		// resolvedDirPath will have been cleaned (no trailing path separators) so
+		// we can manually join it with the base path element.
+		resolvedPath = resolvedDirPath + string(filepath.Separator) + basePath
+		if hasTrailingPathSeparator(path) && filepath.Base(path) != filepath.Base(resolvedPath) {
+			rebaseName = filepath.Base(path)
+		}
+	}
+	return resolvedPath, rebaseName, nil
+}
+
+// GetRebaseName normalizes and compares path and resolvedPath,
+// return completed resolved path and rebased file name
+func GetRebaseName(path, resolvedPath string) (string, string) {
+	// linkTarget will have been cleaned (no trailing path separators and dot) so
+	// we can manually join it with them
+	var rebaseName string
+	if specifiesCurrentDir(path) && !specifiesCurrentDir(resolvedPath) {
+		resolvedPath += string(filepath.Separator) + "."
+	}
+
+	if hasTrailingPathSeparator(path) && !hasTrailingPathSeparator(resolvedPath) {
+		resolvedPath += string(filepath.Separator)
+	}
+
+	if filepath.Base(path) != filepath.Base(resolvedPath) {
+		// In the case where the path had a trailing separator and a symlink
+		// evaluation has changed the last path component, we will need to
+		// rebase the name in the archive that is being copied to match the
+		// originally requested name.
+		rebaseName = filepath.Base(path)
+	}
+	return resolvedPath, rebaseName
+}

vendor/github.com/docker/docker/pkg/archive/copy_unix.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.ToSlash(path)
+}

vendor/github.com/docker/docker/pkg/archive/copy_windows.go

@@ -0,0 +1,9 @@
+package archive
+
+import (
+	"path/filepath"
+)
+
+func normalizePath(path string) string {
+	return filepath.FromSlash(path)
+}

vendor/github.com/docker/docker/pkg/archive/diff.go

@@ -0,0 +1,256 @@
+package archive
+
+import (
+	"archive/tar"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/idtools"
+	"github.com/docker/docker/pkg/pools"
+	"github.com/docker/docker/pkg/system"
+)
+
+// UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func UnpackLayer(dest string, layer io.Reader, options *TarOptions) (size int64, err error) {
+	tr := tar.NewReader(layer)
+	trBuf := pools.BufioReader32KPool.Get(tr)
+	defer pools.BufioReader32KPool.Put(trBuf)
+
+	var dirs []*tar.Header
+	unpackedPaths := make(map[string]struct{})
+
+	if options == nil {
+		options = &TarOptions{}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+	idMappings := idtools.NewIDMappingsFromMaps(options.UIDMaps, options.GIDMaps)
+
+	aufsTempdir := ""
+	aufsHardlinks := make(map[string]*tar.Header)
+
+	// Iterate through the files in the archive.
+	for {
+		hdr, err := tr.Next()
+		if err == io.EOF {
+			// end of tar archive
+			break
+		}
+		if err != nil {
+			return 0, err
+		}
+
+		size += hdr.Size
+
+		// Normalize name, for safety and for a simple is-root check
+		hdr.Name = filepath.Clean(hdr.Name)
+
+		// Windows does not support filenames with colons in them. Ignore
+		// these files. This is not a problem though (although it might
+		// appear that it is). Let's suppose a client is running docker pull.
+		// The daemon it points to is Windows. Would it make sense for the
+		// client to be doing a docker pull Ubuntu for example (which has files
+		// with colons in the name under /usr/share/man/man3)? No, absolutely
+		// not as it would really only make sense that they were pulling a
+		// Windows image. However, for development, it is necessary to be able
+		// to pull Linux images which are in the repository.
+		//
+		// TODO Windows. Once the registry is aware of what images are Windows-
+		// specific or Linux-specific, this warning should be changed to an error
+		// to cater for the situation where someone does manage to upload a Linux
+		// image but have it tagged as Windows inadvertently.
+		if runtime.GOOS == "windows" {
+			if strings.Contains(hdr.Name, ":") {
+				logrus.Warnf("Windows: Ignoring %s (is this a Linux image?)", hdr.Name)
+				continue
+			}
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if !strings.HasSuffix(hdr.Name, string(os.PathSeparator)) {
+			// Not the root directory, ensure that the parent directory exists.
+			// This happened in some tests where an image had a tarfile without any
+			// parent directories.
+			parent := filepath.Dir(hdr.Name)
+			parentPath := filepath.Join(dest, parent)
+
+			if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) {
+				err = system.MkdirAll(parentPath, 0600, "")
+				if err != nil {
+					return 0, err
+				}
+			}
+		}
+
+		// Skip AUFS metadata dirs
+		if strings.HasPrefix(hdr.Name, WhiteoutMetaPrefix) {
+			// Regular files inside /.wh..wh.plnk can be used as hardlink targets
+			// We don't want this directory, but we need the files in them so that
+			// such hardlinks can be resolved.
+			if strings.HasPrefix(hdr.Name, WhiteoutLinkDir) && hdr.Typeflag == tar.TypeReg {
+				basename := filepath.Base(hdr.Name)
+				aufsHardlinks[basename] = hdr
+				if aufsTempdir == "" {
+					if aufsTempdir, err = ioutil.TempDir("", "dockerplnk"); err != nil {
+						return 0, err
+					}
+					defer os.RemoveAll(aufsTempdir)
+				}
+				if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true, nil, options.InUserNS); err != nil {
+					return 0, err
+				}
+			}
+
+			if hdr.Name != WhiteoutOpaqueDir {
+				continue
+			}
+		}
+		path := filepath.Join(dest, hdr.Name)
+		rel, err := filepath.Rel(dest, path)
+		if err != nil {
+			return 0, err
+		}
+
+		// Note as these operations are platform specific, so must the slash be.
+		if strings.HasPrefix(rel, ".."+string(os.PathSeparator)) {
+			return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))
+		}
+		base := filepath.Base(path)
+
+		if strings.HasPrefix(base, WhiteoutPrefix) {
+			dir := filepath.Dir(path)
+			if base == WhiteoutOpaqueDir {
+				_, err := os.Lstat(dir)
+				if err != nil {
+					return 0, err
+				}
+				err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+					if err != nil {
+						if os.IsNotExist(err) {
+							err = nil // parent was deleted
+						}
+						return err
+					}
+					if path == dir {
+						return nil
+					}
+					if _, exists := unpackedPaths[path]; !exists {
+						err := os.RemoveAll(path)
+						return err
+					}
+					return nil
+				})
+				if err != nil {
+					return 0, err
+				}
+			} else {
+				originalBase := base[len(WhiteoutPrefix):]
+				originalPath := filepath.Join(dir, originalBase)
+				if err := os.RemoveAll(originalPath); err != nil {
+					return 0, err
+				}
+			}
+		} else {
+			// If path exits we almost always just want to remove and replace it.
+			// The only exception is when it is a directory *and* the file from
+			// the layer is also a directory. Then we want to merge them (i.e.
+			// just apply the metadata from the layer).
+			if fi, err := os.Lstat(path); err == nil {
+				if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {
+					if err := os.RemoveAll(path); err != nil {
+						return 0, err
+					}
+				}
+			}
+
+			trBuf.Reset(tr)
+			srcData := io.Reader(trBuf)
+			srcHdr := hdr
+
+			// Hard links into /.wh..wh.plnk don't work, as we don't extract that directory, so
+			// we manually retarget these into the temporary files we extracted them into
+			if hdr.Typeflag == tar.TypeLink && strings.HasPrefix(filepath.Clean(hdr.Linkname), WhiteoutLinkDir) {
+				linkBasename := filepath.Base(hdr.Linkname)
+				srcHdr = aufsHardlinks[linkBasename]
+				if srcHdr == nil {
+					return 0, fmt.Errorf("Invalid aufs hardlink")
+				}
+				tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))
+				if err != nil {
+					return 0, err
+				}
+				defer tmpFile.Close()
+				srcData = tmpFile
+			}
+
+			if err := remapIDs(idMappings, srcHdr); err != nil {
+				return 0, err
+			}
+
+			if err := createTarFile(path, dest, srcHdr, srcData, true, nil, options.InUserNS); err != nil {
+				return 0, err
+			}
+
+			// Directory mtimes must be handled at the end to avoid further
+			// file creation in them to modify the directory mtime
+			if hdr.Typeflag == tar.TypeDir {
+				dirs = append(dirs, hdr)
+			}
+			unpackedPaths[path] = struct{}{}
+		}
+	}
+
+	for _, hdr := range dirs {
+		path := filepath.Join(dest, hdr.Name)
+		if err := system.Chtimes(path, hdr.AccessTime, hdr.ModTime); err != nil {
+			return 0, err
+		}
+	}
+
+	return size, nil
+}
+
+// ApplyLayer parses a diff in the standard layer format from `layer`,
+// and applies it to the directory `dest`. The stream `layer` can be
+// compressed or uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyLayer(dest string, layer io.Reader) (int64, error) {
+	return applyLayerHandler(dest, layer, &TarOptions{}, true)
+}
+
+// ApplyUncompressedLayer parses a diff in the standard layer format from
+// `layer`, and applies it to the directory `dest`. The stream `layer`
+// can only be uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyUncompressedLayer(dest string, layer io.Reader, options *TarOptions) (int64, error) {
+	return applyLayerHandler(dest, layer, options, false)
+}
+
+// do the bulk load of ApplyLayer, but allow for not calling DecompressStream
+func applyLayerHandler(dest string, layer io.Reader, options *TarOptions, decompress bool) (int64, error) {
+	dest = filepath.Clean(dest)
+
+	// We need to be able to set any perms
+	oldmask, err := system.Umask(0)
+	if err != nil {
+		return 0, err
+	}
+	defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform
+
+	if decompress {
+		layer, err = DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+	}
+	return UnpackLayer(dest, layer, options)
+}

vendor/github.com/docker/docker/pkg/archive/example_changes.go

@@ -0,0 +1,97 @@
+// +build ignore
+
+// Simple tool to create an archive stream from an old and new directory
+//
+// By default it will stream the comparison of two temporary directories with junk files
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/pkg/archive"
+)
+
+var (
+	flDebug  = flag.Bool("D", false, "debugging output")
+	flNewDir = flag.String("newdir", "", "")
+	flOldDir = flag.String("olddir", "", "")
+	log      = logrus.New()
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
+		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	log.Out = os.Stderr
+	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+	var newDir, oldDir string
+
+	if len(*flNewDir) == 0 {
+		var err error
+		newDir, err = ioutil.TempDir("", "docker-test-newDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(newDir)
+		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		newDir = *flNewDir
+	}
+
+	if len(*flOldDir) == 0 {
+		oldDir, err := ioutil.TempDir("", "docker-test-oldDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(oldDir)
+	} else {
+		oldDir = *flOldDir
+	}
+
+	changes, err := archive.ChangesDirs(newDir, oldDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	a, err := archive.ExportChanges(newDir, changes)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer a.Close()
+
+	i, err := io.Copy(os.Stdout, a)
+	if err != nil && err != io.EOF {
+		log.Fatal(err)
+	}
+	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
+}
+
+func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
+	fileData := []byte("fooo")
+	for n := 0; n < numberOfFiles; n++ {
+		fileName := fmt.Sprintf("file-%d", n)
+		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
+			return 0, err
+		}
+		if makeLinks {
+			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
+				return 0, err
+			}
+		}
+	}
+	totalSize := numberOfFiles * len(fileData)
+	return totalSize, nil
+}

vendor/github.com/docker/docker/pkg/archive/time_linux.go

@@ -0,0 +1,16 @@
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	if time.IsZero() {
+		// Return UTIME_OMIT special value
+		ts.Sec = 0
+		ts.Nsec = ((1 << 30) - 2)
+		return
+	}
+	return syscall.NsecToTimespec(time.UnixNano())
+}

vendor/github.com/docker/docker/pkg/archive/time_unsupported.go

@@ -0,0 +1,16 @@
+// +build !linux
+
+package archive
+
+import (
+	"syscall"
+	"time"
+)
+
+func timeToTimespec(time time.Time) (ts syscall.Timespec) {
+	nsec := int64(0)
+	if !time.IsZero() {
+		nsec = time.UnixNano()
+	}
+	return syscall.NsecToTimespec(nsec)
+}

vendor/github.com/docker/docker/pkg/archive/whiteouts.go

@@ -0,0 +1,23 @@
+package archive
+
+// Whiteouts are files with a special meaning for the layered filesystem.
+// Docker uses AUFS whiteout files inside exported archives. In other
+// filesystems these files are generated/handled on tar creation/extraction.
+
+// WhiteoutPrefix prefix means file is a whiteout. If this is followed by a
+// filename this means that file has been removed from the base layer.
+const WhiteoutPrefix = ".wh."
+
+// WhiteoutMetaPrefix prefix means whiteout has a special meaning and is not
+// for removing an actual file. Normally these files are excluded from exported
+// archives.
+const WhiteoutMetaPrefix = WhiteoutPrefix + WhiteoutPrefix
+
+// WhiteoutLinkDir is a directory AUFS uses for storing hardlink links to other
+// layers. Normally these should not go into exported archives and all changed
+// hardlinks should be copied to the top layer.
+const WhiteoutLinkDir = WhiteoutMetaPrefix + "plnk"
+
+// WhiteoutOpaqueDir file means directory has been made opaque - meaning
+// readdir calls to this directory do not follow to lower layers.
+const WhiteoutOpaqueDir = WhiteoutMetaPrefix + ".opq"

vendor/github.com/docker/docker/pkg/archive/wrap.go

@@ -0,0 +1,59 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"io"
+)
+
+// Generate generates a new archive from the content provided
+// as input.
+//
+// `files` is a sequence of path/content pairs. A new file is
+// added to the archive for each pair.
+// If the last pair is incomplete, the file is created with an
+// empty content. For example:
+//
+// Generate("foo.txt", "hello world", "emptyfile")
+//
+// The above call will return an archive with 2 files:
+//  * ./foo.txt with content "hello world"
+//  * ./empty with empty content
+//
+// FIXME: stream content instead of buffering
+// FIXME: specify permissions and other archive metadata
+func Generate(input ...string) (io.Reader, error) {
+	files := parseStringPairs(input...)
+	buf := new(bytes.Buffer)
+	tw := tar.NewWriter(buf)
+	for _, file := range files {
+		name, content := file[0], file[1]
+		hdr := &tar.Header{
+			Name: name,
+			Size: int64(len(content)),
+		}
+		if err := tw.WriteHeader(hdr); err != nil {
+			return nil, err
+		}
+		if _, err := tw.Write([]byte(content)); err != nil {
+			return nil, err
+		}
+	}
+	if err := tw.Close(); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func parseStringPairs(input ...string) (output [][2]string) {
+	output = make([][2]string, 0, len(input)/2+1)
+	for i := 0; i < len(input); i += 2 {
+		var pair [2]string
+		pair[0] = input[i]
+		if i+1 < len(input) {
+			pair[1] = input[i+1]
+		}
+		output = append(output, pair)
+	}
+	return
+}

vendor/github.com/docker/docker/pkg/chrootarchive/archive.go

@@ -0,0 +1,70 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/idtools"
+)
+
+// NewArchiver returns a new Archiver which uses chrootarchive.Untar
+func NewArchiver(idMappings *idtools.IDMappings) *archive.Archiver {
+	if idMappings == nil {
+		idMappings = &idtools.IDMappings{}
+	}
+	return &archive.Archiver{Untar: Untar, IDMappings: idMappings}
+}
+
+// Untar reads a stream of bytes from `archive`, parses it as a tar archive,
+// and unpacks it into the directory at `dest`.
+// The archive may be compressed with one of the following algorithms:
+//  identity (uncompressed), gzip, bzip2, xz.
+func Untar(tarArchive io.Reader, dest string, options *archive.TarOptions) error {
+	return untarHandler(tarArchive, dest, options, true)
+}
+
+// UntarUncompressed reads a stream of bytes from `archive`, parses it as a tar archive,
+// and unpacks it into the directory at `dest`.
+// The archive must be an uncompressed stream.
+func UntarUncompressed(tarArchive io.Reader, dest string, options *archive.TarOptions) error {
+	return untarHandler(tarArchive, dest, options, false)
+}
+
+// Handler for teasing out the automatic decompression
+func untarHandler(tarArchive io.Reader, dest string, options *archive.TarOptions, decompress bool) error {
+	if tarArchive == nil {
+		return fmt.Errorf("Empty archive")
+	}
+	if options == nil {
+		options = &archive.TarOptions{}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+
+	idMappings := idtools.NewIDMappingsFromMaps(options.UIDMaps, options.GIDMaps)
+	rootIDs := idMappings.RootPair()
+
+	dest = filepath.Clean(dest)
+	if _, err := os.Stat(dest); os.IsNotExist(err) {
+		if err := idtools.MkdirAllAndChownNew(dest, 0755, rootIDs); err != nil {
+			return err
+		}
+	}
+
+	r := ioutil.NopCloser(tarArchive)
+	if decompress {
+		decompressedArchive, err := archive.DecompressStream(tarArchive)
+		if err != nil {
+			return err
+		}
+		defer decompressedArchive.Close()
+		r = decompressedArchive
+	}
+
+	return invokeUnpack(r, dest, options)
+}

vendor/github.com/docker/docker/pkg/chrootarchive/archive_unix.go

@@ -0,0 +1,86 @@
+// +build !windows
+
+package chrootarchive
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"runtime"
+
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/reexec"
+)
+
+// untar is the entry-point for docker-untar on re-exec. This is not used on
+// Windows as it does not support chroot, hence no point sandboxing through
+// chroot and rexec.
+func untar() {
+	runtime.LockOSThread()
+	flag.Parse()
+
+	var options *archive.TarOptions
+
+	//read the options from the pipe "ExtraFiles"
+	if err := json.NewDecoder(os.NewFile(3, "options")).Decode(&options); err != nil {
+		fatal(err)
+	}
+
+	if err := chroot(flag.Arg(0)); err != nil {
+		fatal(err)
+	}
+
+	if err := archive.Unpack(os.Stdin, "/", options); err != nil {
+		fatal(err)
+	}
+	// fully consume stdin in case it is zero padded
+	if _, err := flush(os.Stdin); err != nil {
+		fatal(err)
+	}
+
+	os.Exit(0)
+}
+
+func invokeUnpack(decompressedArchive io.Reader, dest string, options *archive.TarOptions) error {
+
+	// We can't pass a potentially large exclude list directly via cmd line
+	// because we easily overrun the kernel's max argument/environment size
+	// when the full image list is passed (e.g. when this is used by
+	// `docker load`). We will marshall the options via a pipe to the
+	// child
+	r, w, err := os.Pipe()
+	if err != nil {
+		return fmt.Errorf("Untar pipe failure: %v", err)
+	}
+
+	cmd := reexec.Command("docker-untar", dest)
+	cmd.Stdin = decompressedArchive
+
+	cmd.ExtraFiles = append(cmd.ExtraFiles, r)
+	output := bytes.NewBuffer(nil)
+	cmd.Stdout = output
+	cmd.Stderr = output
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("Untar error on re-exec cmd: %v", err)
+	}
+	//write the options to the pipe for the untar exec to read
+	if err := json.NewEncoder(w).Encode(options); err != nil {
+		return fmt.Errorf("Untar json encode to pipe failed: %v", err)
+	}
+	w.Close()
+
+	if err := cmd.Wait(); err != nil {
+		// when `xz -d -c -q | docker-untar ...` failed on docker-untar side,
+		// we need to exhaust `xz`'s output, otherwise the `xz` side will be
+		// pending on write pipe forever
+		io.Copy(ioutil.Discard, decompressedArchive)
+
+		return fmt.Errorf("Error processing tar file(%v): %s", err, output)
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/chrootarchive/archive_windows.go

@@ -0,0 +1,22 @@
+package chrootarchive
+
+import (
+	"io"
+
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// chroot is not supported by Windows
+func chroot(path string) error {
+	return nil
+}
+
+func invokeUnpack(decompressedArchive io.ReadCloser,
+	dest string,
+	options *archive.TarOptions) error {
+	// Windows is different to Linux here because Windows does not support
+	// chroot. Hence there is no point sandboxing a chrooted process to
+	// do the unpack. We call inline instead within the daemon process.
+	return archive.Unpack(decompressedArchive, longpath.AddPrefix(dest), options)
+}

vendor/github.com/docker/docker/pkg/chrootarchive/chroot_linux.go

@@ -0,0 +1,108 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/docker/docker/pkg/mount"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+)
+
+// chroot on linux uses pivot_root instead of chroot
+// pivot_root takes a new root and an old root.
+// Old root must be a sub-dir of new root, it is where the current rootfs will reside after the call to pivot_root.
+// New root is where the new rootfs is set to.
+// Old root is removed after the call to pivot_root so it is no longer available under the new root.
+// This is similar to how libcontainer sets up a container's rootfs
+func chroot(path string) (err error) {
+	// if the engine is running in a user namespace we need to use actual chroot
+	if rsystem.RunningInUserNS() {
+		return realChroot(path)
+	}
+	if err := syscall.Unshare(syscall.CLONE_NEWNS); err != nil {
+		return fmt.Errorf("Error creating mount namespace before pivot: %v", err)
+	}
+
+	// make everything in new ns private
+	if err := mount.MakeRPrivate("/"); err != nil {
+		return err
+	}
+
+	if mounted, _ := mount.Mounted(path); !mounted {
+		if err := mount.Mount(path, path, "bind", "rbind,rw"); err != nil {
+			return realChroot(path)
+		}
+	}
+
+	// setup oldRoot for pivot_root
+	pivotDir, err := ioutil.TempDir(path, ".pivot_root")
+	if err != nil {
+		return fmt.Errorf("Error setting up pivot dir: %v", err)
+	}
+
+	var mounted bool
+	defer func() {
+		if mounted {
+			// make sure pivotDir is not mounted before we try to remove it
+			if errCleanup := syscall.Unmount(pivotDir, syscall.MNT_DETACH); errCleanup != nil {
+				if err == nil {
+					err = errCleanup
+				}
+				return
+			}
+		}
+
+		errCleanup := os.Remove(pivotDir)
+		// pivotDir doesn't exist if pivot_root failed and chroot+chdir was successful
+		// because we already cleaned it up on failed pivot_root
+		if errCleanup != nil && !os.IsNotExist(errCleanup) {
+			errCleanup = fmt.Errorf("Error cleaning up after pivot: %v", errCleanup)
+			if err == nil {
+				err = errCleanup
+			}
+		}
+	}()
+
+	if err := syscall.PivotRoot(path, pivotDir); err != nil {
+		// If pivot fails, fall back to the normal chroot after cleaning up temp dir
+		if err := os.Remove(pivotDir); err != nil {
+			return fmt.Errorf("Error cleaning up after failed pivot: %v", err)
+		}
+		return realChroot(path)
+	}
+	mounted = true
+
+	// This is the new path for where the old root (prior to the pivot) has been moved to
+	// This dir contains the rootfs of the caller, which we need to remove so it is not visible during extraction
+	pivotDir = filepath.Join("/", filepath.Base(pivotDir))
+
+	if err := syscall.Chdir("/"); err != nil {
+		return fmt.Errorf("Error changing to new root: %v", err)
+	}
+
+	// Make the pivotDir (where the old root lives) private so it can be unmounted without propagating to the host
+	if err := syscall.Mount("", pivotDir, "", syscall.MS_PRIVATE|syscall.MS_REC, ""); err != nil {
+		return fmt.Errorf("Error making old root private after pivot: %v", err)
+	}
+
+	// Now unmount the old root so it's no longer visible from the new root
+	if err := syscall.Unmount(pivotDir, syscall.MNT_DETACH); err != nil {
+		return fmt.Errorf("Error while unmounting old root after pivot: %v", err)
+	}
+	mounted = false
+
+	return nil
+}
+
+func realChroot(path string) error {
+	if err := syscall.Chroot(path); err != nil {
+		return fmt.Errorf("Error after fallback to chroot: %v", err)
+	}
+	if err := syscall.Chdir("/"); err != nil {
+		return fmt.Errorf("Error changing to new root after chroot: %v", err)
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/chrootarchive/chroot_unix.go

@@ -0,0 +1,12 @@
+// +build !windows,!linux
+
+package chrootarchive
+
+import "syscall"
+
+func chroot(path string) error {
+	if err := syscall.Chroot(path); err != nil {
+		return err
+	}
+	return syscall.Chdir("/")
+}

vendor/github.com/docker/docker/pkg/chrootarchive/diff.go

@@ -0,0 +1,23 @@
+package chrootarchive
+
+import (
+	"io"
+
+	"github.com/docker/docker/pkg/archive"
+)
+
+// ApplyLayer parses a diff in the standard layer format from `layer`,
+// and applies it to the directory `dest`. The stream `layer` can only be
+// uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyLayer(dest string, layer io.Reader) (size int64, err error) {
+	return applyLayerHandler(dest, layer, &archive.TarOptions{}, true)
+}
+
+// ApplyUncompressedLayer parses a diff in the standard layer format from
+// `layer`, and applies it to the directory `dest`. The stream `layer`
+// can only be uncompressed.
+// Returns the size in bytes of the contents of the layer.
+func ApplyUncompressedLayer(dest string, layer io.Reader, options *archive.TarOptions) (int64, error) {
+	return applyLayerHandler(dest, layer, options, false)
+}

vendor/github.com/docker/docker/pkg/chrootarchive/diff_unix.go

@@ -0,0 +1,130 @@
+//+build !windows
+
+package chrootarchive
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/reexec"
+	"github.com/docker/docker/pkg/system"
+	rsystem "github.com/opencontainers/runc/libcontainer/system"
+)
+
+type applyLayerResponse struct {
+	LayerSize int64 `json:"layerSize"`
+}
+
+// applyLayer is the entry-point for docker-applylayer on re-exec. This is not
+// used on Windows as it does not support chroot, hence no point sandboxing
+// through chroot and rexec.
+func applyLayer() {
+
+	var (
+		tmpDir  string
+		err     error
+		options *archive.TarOptions
+	)
+	runtime.LockOSThread()
+	flag.Parse()
+
+	inUserns := rsystem.RunningInUserNS()
+	if err := chroot(flag.Arg(0)); err != nil {
+		fatal(err)
+	}
+
+	// We need to be able to set any perms
+	oldmask, err := system.Umask(0)
+	defer system.Umask(oldmask)
+	if err != nil {
+		fatal(err)
+	}
+
+	if err := json.Unmarshal([]byte(os.Getenv("OPT")), &options); err != nil {
+		fatal(err)
+	}
+
+	if inUserns {
+		options.InUserNS = true
+	}
+
+	if tmpDir, err = ioutil.TempDir("/", "temp-docker-extract"); err != nil {
+		fatal(err)
+	}
+
+	os.Setenv("TMPDIR", tmpDir)
+	size, err := archive.UnpackLayer("/", os.Stdin, options)
+	os.RemoveAll(tmpDir)
+	if err != nil {
+		fatal(err)
+	}
+
+	encoder := json.NewEncoder(os.Stdout)
+	if err := encoder.Encode(applyLayerResponse{size}); err != nil {
+		fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))
+	}
+
+	if _, err := flush(os.Stdin); err != nil {
+		fatal(err)
+	}
+
+	os.Exit(0)
+}
+
+// applyLayerHandler parses a diff in the standard layer format from `layer`, and
+// applies it to the directory `dest`. Returns the size in bytes of the
+// contents of the layer.
+func applyLayerHandler(dest string, layer io.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
+	dest = filepath.Clean(dest)
+	if decompress {
+		decompressed, err := archive.DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+		defer decompressed.Close()
+
+		layer = decompressed
+	}
+	if options == nil {
+		options = &archive.TarOptions{}
+		if rsystem.RunningInUserNS() {
+			options.InUserNS = true
+		}
+	}
+	if options.ExcludePatterns == nil {
+		options.ExcludePatterns = []string{}
+	}
+
+	data, err := json.Marshal(options)
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer json encode: %v", err)
+	}
+
+	cmd := reexec.Command("docker-applyLayer", dest)
+	cmd.Stdin = layer
+	cmd.Env = append(cmd.Env, fmt.Sprintf("OPT=%s", data))
+
+	outBuf, errBuf := new(bytes.Buffer), new(bytes.Buffer)
+	cmd.Stdout, cmd.Stderr = outBuf, errBuf
+
+	if err = cmd.Run(); err != nil {
+		return 0, fmt.Errorf("ApplyLayer %s stdout: %s stderr: %s", err, outBuf, errBuf)
+	}
+
+	// Stdout should be a valid JSON struct representing an applyLayerResponse.
+	response := applyLayerResponse{}
+	decoder := json.NewDecoder(outBuf)
+	if err = decoder.Decode(&response); err != nil {
+		return 0, fmt.Errorf("unable to decode ApplyLayer JSON response: %s", err)
+	}
+
+	return response.LayerSize, nil
+}

vendor/github.com/docker/docker/pkg/chrootarchive/diff_windows.go

@@ -0,0 +1,45 @@
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/docker/docker/pkg/archive"
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// applyLayerHandler parses a diff in the standard layer format from `layer`, and
+// applies it to the directory `dest`. Returns the size in bytes of the
+// contents of the layer.
+func applyLayerHandler(dest string, layer io.Reader, options *archive.TarOptions, decompress bool) (size int64, err error) {
+	dest = filepath.Clean(dest)
+
+	// Ensure it is a Windows-style volume path
+	dest = longpath.AddPrefix(dest)
+
+	if decompress {
+		decompressed, err := archive.DecompressStream(layer)
+		if err != nil {
+			return 0, err
+		}
+		defer decompressed.Close()
+
+		layer = decompressed
+	}
+
+	tmpDir, err := ioutil.TempDir(os.Getenv("temp"), "temp-docker-extract")
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer failed to create temp-docker-extract under %s. %s", dest, err)
+	}
+
+	s, err := archive.UnpackLayer(dest, layer, nil)
+	os.RemoveAll(tmpDir)
+	if err != nil {
+		return 0, fmt.Errorf("ApplyLayer %s failed UnpackLayer to %s: %s", layer, dest, err)
+	}
+
+	return s, nil
+}

vendor/github.com/docker/docker/pkg/chrootarchive/init_unix.go

@@ -0,0 +1,28 @@
+// +build !windows
+
+package chrootarchive
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/docker/docker/pkg/reexec"
+)
+
+func init() {
+	reexec.Register("docker-applyLayer", applyLayer)
+	reexec.Register("docker-untar", untar)
+}
+
+func fatal(err error) {
+	fmt.Fprint(os.Stderr, err)
+	os.Exit(1)
+}
+
+// flush consumes all the bytes from the reader discarding
+// any errors
+func flush(r io.Reader) (bytes int64, err error) {
+	return io.Copy(ioutil.Discard, r)
+}

vendor/github.com/docker/docker/pkg/chrootarchive/init_windows.go

@@ -0,0 +1,4 @@
+package chrootarchive
+
+func init() {
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils.go

@@ -0,0 +1,298 @@
+package fileutils
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"text/scanner"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// PatternMatcher allows checking paths agaist a list of patterns
+type PatternMatcher struct {
+	patterns   []*Pattern
+	exclusions bool
+}
+
+// NewPatternMatcher creates a new matcher object for specific patterns that can
+// be used later to match against patterns against paths
+func NewPatternMatcher(patterns []string) (*PatternMatcher, error) {
+	pm := &PatternMatcher{
+		patterns: make([]*Pattern, 0, len(patterns)),
+	}
+	for _, p := range patterns {
+		// Eliminate leading and trailing whitespace.
+		p = strings.TrimSpace(p)
+		if p == "" {
+			continue
+		}
+		p = filepath.Clean(p)
+		newp := &Pattern{}
+		if p[0] == '!' {
+			if len(p) == 1 {
+				return nil, errors.New("illegal exclusion pattern: \"!\"")
+			}
+			newp.exclusion = true
+			p = p[1:]
+			pm.exclusions = true
+		}
+		// Do some syntax checking on the pattern.
+		// filepath's Match() has some really weird rules that are inconsistent
+		// so instead of trying to dup their logic, just call Match() for its
+		// error state and if there is an error in the pattern return it.
+		// If this becomes an issue we can remove this since its really only
+		// needed in the error (syntax) case - which isn't really critical.
+		if _, err := filepath.Match(p, "."); err != nil {
+			return nil, err
+		}
+		newp.cleanedPattern = p
+		newp.dirs = strings.Split(p, string(os.PathSeparator))
+		pm.patterns = append(pm.patterns, newp)
+	}
+	return pm, nil
+}
+
+// Matches matches path against all the patterns. Matches is not safe to be
+// called concurrently
+func (pm *PatternMatcher) Matches(file string) (bool, error) {
+	matched := false
+	file = filepath.FromSlash(file)
+	parentPath := filepath.Dir(file)
+	parentPathDirs := strings.Split(parentPath, string(os.PathSeparator))
+
+	for _, pattern := range pm.patterns {
+		negative := false
+
+		if pattern.exclusion {
+			negative = true
+		}
+
+		match, err := pattern.match(file)
+		if err != nil {
+			return false, err
+		}
+
+		if !match && parentPath != "." {
+			// Check to see if the pattern matches one of our parent dirs.
+			if len(pattern.dirs) <= len(parentPathDirs) {
+				match, _ = pattern.match(strings.Join(parentPathDirs[:len(pattern.dirs)], string(os.PathSeparator)))
+			}
+		}
+
+		if match {
+			matched = !negative
+		}
+	}
+
+	if matched {
+		logrus.Debugf("Skipping excluded path: %s", file)
+	}
+
+	return matched, nil
+}
+
+// Exclusions returns true if any of the patterns define exclusions
+func (pm *PatternMatcher) Exclusions() bool {
+	return pm.exclusions
+}
+
+// Patterns returns array of active patterns
+func (pm *PatternMatcher) Patterns() []*Pattern {
+	return pm.patterns
+}
+
+// Pattern defines a single regexp used used to filter file paths.
+type Pattern struct {
+	cleanedPattern string
+	dirs           []string
+	regexp         *regexp.Regexp
+	exclusion      bool
+}
+
+func (p *Pattern) String() string {
+	return p.cleanedPattern
+}
+
+// Exclusion returns true if this pattern defines exclusion
+func (p *Pattern) Exclusion() bool {
+	return p.exclusion
+}
+
+func (p *Pattern) match(path string) (bool, error) {
+
+	if p.regexp == nil {
+		if err := p.compile(); err != nil {
+			return false, filepath.ErrBadPattern
+		}
+	}
+
+	b := p.regexp.MatchString(path)
+
+	return b, nil
+}
+
+func (p *Pattern) compile() error {
+	regStr := "^"
+	pattern := p.cleanedPattern
+	// Go through the pattern and convert it to a regexp.
+	// We use a scanner so we can support utf-8 chars.
+	var scan scanner.Scanner
+	scan.Init(strings.NewReader(pattern))
+
+	sl := string(os.PathSeparator)
+	escSL := sl
+	if sl == `\` {
+		escSL += `\`
+	}
+
+	for scan.Peek() != scanner.EOF {
+		ch := scan.Next()
+
+		if ch == '*' {
+			if scan.Peek() == '*' {
+				// is some flavor of "**"
+				scan.Next()
+
+				// Treat **/ as ** so eat the "/"
+				if string(scan.Peek()) == sl {
+					scan.Next()
+				}
+
+				if scan.Peek() == scanner.EOF {
+					// is "**EOF" - to align with .gitignore just accept all
+					regStr += ".*"
+				} else {
+					// is "**"
+					// Note that this allows for any # of /'s (even 0) because
+					// the .* will eat everything, even /'s
+					regStr += "(.*" + escSL + ")?"
+				}
+			} else {
+				// is "*" so map it to anything but "/"
+				regStr += "[^" + escSL + "]*"
+			}
+		} else if ch == '?' {
+			// "?" is any char except "/"
+			regStr += "[^" + escSL + "]"
+		} else if ch == '.' || ch == '$' {
+			// Escape some regexp special chars that have no meaning
+			// in golang's filepath.Match
+			regStr += `\` + string(ch)
+		} else if ch == '\\' {
+			// escape next char. Note that a trailing \ in the pattern
+			// will be left alone (but need to escape it)
+			if sl == `\` {
+				// On windows map "\" to "\\", meaning an escaped backslash,
+				// and then just continue because filepath.Match on
+				// Windows doesn't allow escaping at all
+				regStr += escSL
+				continue
+			}
+			if scan.Peek() != scanner.EOF {
+				regStr += `\` + string(scan.Next())
+			} else {
+				regStr += `\`
+			}
+		} else {
+			regStr += string(ch)
+		}
+	}
+
+	regStr += "$"
+
+	re, err := regexp.Compile(regStr)
+	if err != nil {
+		return err
+	}
+
+	p.regexp = re
+	return nil
+}
+
+// Matches returns true if file matches any of the patterns
+// and isn't excluded by any of the subsequent patterns.
+func Matches(file string, patterns []string) (bool, error) {
+	pm, err := NewPatternMatcher(patterns)
+	if err != nil {
+		return false, err
+	}
+	file = filepath.Clean(file)
+
+	if file == "." {
+		// Don't let them exclude everything, kind of silly.
+		return false, nil
+	}
+
+	return pm.Matches(file)
+}
+
+// CopyFile copies from src to dst until either EOF is reached
+// on src or an error occurs. It verifies src exists and removes
+// the dst if it exists.
+func CopyFile(src, dst string) (int64, error) {
+	cleanSrc := filepath.Clean(src)
+	cleanDst := filepath.Clean(dst)
+	if cleanSrc == cleanDst {
+		return 0, nil
+	}
+	sf, err := os.Open(cleanSrc)
+	if err != nil {
+		return 0, err
+	}
+	defer sf.Close()
+	if err := os.Remove(cleanDst); err != nil && !os.IsNotExist(err) {
+		return 0, err
+	}
+	df, err := os.Create(cleanDst)
+	if err != nil {
+		return 0, err
+	}
+	defer df.Close()
+	return io.Copy(df, sf)
+}
+
+// ReadSymlinkedDirectory returns the target directory of a symlink.
+// The target of the symbolic link may not be a file.
+func ReadSymlinkedDirectory(path string) (string, error) {
+	var realPath string
+	var err error
+	if realPath, err = filepath.Abs(path); err != nil {
+		return "", fmt.Errorf("unable to get absolute path for %s: %s", path, err)
+	}
+	if realPath, err = filepath.EvalSymlinks(realPath); err != nil {
+		return "", fmt.Errorf("failed to canonicalise path for %s: %s", path, err)
+	}
+	realPathInfo, err := os.Stat(realPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to stat target '%s' of '%s': %s", realPath, path, err)
+	}
+	if !realPathInfo.Mode().IsDir() {
+		return "", fmt.Errorf("canonical path points to a file '%s'", realPath)
+	}
+	return realPath, nil
+}
+
+// CreateIfNotExists creates a file or a directory only if it does not already exist.
+func CreateIfNotExists(path string, isDir bool) error {
+	if _, err := os.Stat(path); err != nil {
+		if os.IsNotExist(err) {
+			if isDir {
+				return os.MkdirAll(path, 0755)
+			}
+			if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+				return err
+			}
+			f, err := os.OpenFile(path, os.O_CREATE, 0755)
+			if err != nil {
+				return err
+			}
+			f.Close()
+		}
+	}
+	return nil
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_darwin.go

@@ -0,0 +1,27 @@
+package fileutils
+
+import (
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// GetTotalUsedFds returns the number of used File Descriptors by
+// executing `lsof -p PID`
+func GetTotalUsedFds() int {
+	pid := os.Getpid()
+
+	cmd := exec.Command("lsof", "-p", strconv.Itoa(pid))
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return -1
+	}
+
+	outputStr := strings.TrimSpace(string(output))
+
+	fds := strings.Split(outputStr, "\n")
+
+	return len(fds) - 1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_solaris.go

@@ -0,0 +1,7 @@
+package fileutils
+
+// GetTotalUsedFds Returns the number of used File Descriptors.
+// On Solaris these limits are per process and not systemwide
+func GetTotalUsedFds() int {
+	return -1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_unix.go

@@ -0,0 +1,22 @@
+// +build linux freebsd
+
+package fileutils
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// GetTotalUsedFds Returns the number of used File Descriptors by
+// reading it via /proc filesystem.
+func GetTotalUsedFds() int {
+	if fds, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/fd", os.Getpid())); err != nil {
+		logrus.Errorf("Error opening /proc/%d/fd: %s", os.Getpid(), err)
+	} else {
+		return len(fds)
+	}
+	return -1
+}

vendor/github.com/docker/docker/pkg/fileutils/fileutils_windows.go

@@ -0,0 +1,7 @@
+package fileutils
+
+// GetTotalUsedFds Returns the number of used File Descriptors. Not supported
+// on Windows.
+func GetTotalUsedFds() int {
+	return -1
+}

vendor/github.com/docker/docker/pkg/idtools/idtools.go

@@ -0,0 +1,279 @@
+package idtools
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// IDMap contains a single entry for user namespace range remapping. An array
+// of IDMap entries represents the structure that will be provided to the Linux
+// kernel for creating a user namespace.
+type IDMap struct {
+	ContainerID int `json:"container_id"`
+	HostID      int `json:"host_id"`
+	Size        int `json:"size"`
+}
+
+type subIDRange struct {
+	Start  int
+	Length int
+}
+
+type ranges []subIDRange
+
+func (e ranges) Len() int           { return len(e) }
+func (e ranges) Swap(i, j int)      { e[i], e[j] = e[j], e[i] }
+func (e ranges) Less(i, j int) bool { return e[i].Start < e[j].Start }
+
+const (
+	subuidFileName string = "/etc/subuid"
+	subgidFileName string = "/etc/subgid"
+)
+
+// MkdirAllAs creates a directory (include any along the path) and then modifies
+// ownership to the requested uid/gid.  If the directory already exists, this
+// function will still change ownership to the requested uid/gid pair.
+// Deprecated: Use MkdirAllAndChown
+func MkdirAllAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	return mkdirAs(path, mode, ownerUID, ownerGID, true, true)
+}
+
+// MkdirAs creates a directory and then modifies ownership to the requested uid/gid.
+// If the directory already exists, this function still changes ownership
+// Deprecated: Use MkdirAndChown with a IDPair
+func MkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int) error {
+	return mkdirAs(path, mode, ownerUID, ownerGID, false, true)
+}
+
+// MkdirAllAndChown creates a directory (include any along the path) and then modifies
+// ownership to the requested uid/gid.  If the directory already exists, this
+// function will still change ownership to the requested uid/gid pair.
+func MkdirAllAndChown(path string, mode os.FileMode, ids IDPair) error {
+	return mkdirAs(path, mode, ids.UID, ids.GID, true, true)
+}
+
+// MkdirAndChown creates a directory and then modifies ownership to the requested uid/gid.
+// If the directory already exists, this function still changes ownership
+func MkdirAndChown(path string, mode os.FileMode, ids IDPair) error {
+	return mkdirAs(path, mode, ids.UID, ids.GID, false, true)
+}
+
+// MkdirAllAndChownNew creates a directory (include any along the path) and then modifies
+// ownership ONLY of newly created directories to the requested uid/gid. If the
+// directories along the path exist, no change of ownership will be performed
+func MkdirAllAndChownNew(path string, mode os.FileMode, ids IDPair) error {
+	return mkdirAs(path, mode, ids.UID, ids.GID, true, false)
+}
+
+// GetRootUIDGID retrieves the remapped root uid/gid pair from the set of maps.
+// If the maps are empty, then the root uid/gid will default to "real" 0/0
+func GetRootUIDGID(uidMap, gidMap []IDMap) (int, int, error) {
+	uid, err := toHost(0, uidMap)
+	if err != nil {
+		return -1, -1, err
+	}
+	gid, err := toHost(0, gidMap)
+	if err != nil {
+		return -1, -1, err
+	}
+	return uid, gid, nil
+}
+
+// toContainer takes an id mapping, and uses it to translate a
+// host ID to the remapped ID. If no map is provided, then the translation
+// assumes a 1-to-1 mapping and returns the passed in id
+func toContainer(hostID int, idMap []IDMap) (int, error) {
+	if idMap == nil {
+		return hostID, nil
+	}
+	for _, m := range idMap {
+		if (hostID >= m.HostID) && (hostID <= (m.HostID + m.Size - 1)) {
+			contID := m.ContainerID + (hostID - m.HostID)
+			return contID, nil
+		}
+	}
+	return -1, fmt.Errorf("Host ID %d cannot be mapped to a container ID", hostID)
+}
+
+// toHost takes an id mapping and a remapped ID, and translates the
+// ID to the mapped host ID. If no map is provided, then the translation
+// assumes a 1-to-1 mapping and returns the passed in id #
+func toHost(contID int, idMap []IDMap) (int, error) {
+	if idMap == nil {
+		return contID, nil
+	}
+	for _, m := range idMap {
+		if (contID >= m.ContainerID) && (contID <= (m.ContainerID + m.Size - 1)) {
+			hostID := m.HostID + (contID - m.ContainerID)
+			return hostID, nil
+		}
+	}
+	return -1, fmt.Errorf("Container ID %d cannot be mapped to a host ID", contID)
+}
+
+// IDPair is a UID and GID pair
+type IDPair struct {
+	UID int
+	GID int
+}
+
+// IDMappings contains a mappings of UIDs and GIDs
+type IDMappings struct {
+	uids []IDMap
+	gids []IDMap
+}
+
+// NewIDMappings takes a requested user and group name and
+// using the data from /etc/sub{uid,gid} ranges, creates the
+// proper uid and gid remapping ranges for that user/group pair
+func NewIDMappings(username, groupname string) (*IDMappings, error) {
+	subuidRanges, err := parseSubuid(username)
+	if err != nil {
+		return nil, err
+	}
+	subgidRanges, err := parseSubgid(groupname)
+	if err != nil {
+		return nil, err
+	}
+	if len(subuidRanges) == 0 {
+		return nil, fmt.Errorf("No subuid ranges found for user %q", username)
+	}
+	if len(subgidRanges) == 0 {
+		return nil, fmt.Errorf("No subgid ranges found for group %q", groupname)
+	}
+
+	return &IDMappings{
+		uids: createIDMap(subuidRanges),
+		gids: createIDMap(subgidRanges),
+	}, nil
+}
+
+// NewIDMappingsFromMaps creates a new mapping from two slices
+// Deprecated: this is a temporary shim while transitioning to IDMapping
+func NewIDMappingsFromMaps(uids []IDMap, gids []IDMap) *IDMappings {
+	return &IDMappings{uids: uids, gids: gids}
+}
+
+// RootPair returns a uid and gid pair for the root user. The error is ignored
+// because a root user always exists, and the defaults are correct when the uid
+// and gid maps are empty.
+func (i *IDMappings) RootPair() IDPair {
+	uid, gid, _ := GetRootUIDGID(i.uids, i.gids)
+	return IDPair{UID: uid, GID: gid}
+}
+
+// ToHost returns the host UID and GID for the container uid, gid.
+// Remapping is only performed if the ids aren't already the remapped root ids
+func (i *IDMappings) ToHost(pair IDPair) (IDPair, error) {
+	var err error
+	target := i.RootPair()
+
+	if pair.UID != target.UID {
+		target.UID, err = toHost(pair.UID, i.uids)
+		if err != nil {
+			return target, err
+		}
+	}
+
+	if pair.GID != target.GID {
+		target.GID, err = toHost(pair.GID, i.gids)
+	}
+	return target, err
+}
+
+// ToContainer returns the container UID and GID for the host uid and gid
+func (i *IDMappings) ToContainer(pair IDPair) (int, int, error) {
+	uid, err := toContainer(pair.UID, i.uids)
+	if err != nil {
+		return -1, -1, err
+	}
+	gid, err := toContainer(pair.GID, i.gids)
+	return uid, gid, err
+}
+
+// Empty returns true if there are no id mappings
+func (i *IDMappings) Empty() bool {
+	return len(i.uids) == 0 && len(i.gids) == 0
+}
+
+// UIDs return the UID mapping
+// TODO: remove this once everything has been refactored to use pairs
+func (i *IDMappings) UIDs() []IDMap {
+	return i.uids
+}
+
+// GIDs return the UID mapping
+// TODO: remove this once everything has been refactored to use pairs
+func (i *IDMappings) GIDs() []IDMap {
+	return i.gids
+}
+
+func createIDMap(subidRanges ranges) []IDMap {
+	idMap := []IDMap{}
+
+	// sort the ranges by lowest ID first
+	sort.Sort(subidRanges)
+	containerID := 0
+	for _, idrange := range subidRanges {
+		idMap = append(idMap, IDMap{
+			ContainerID: containerID,
+			HostID:      idrange.Start,
+			Size:        idrange.Length,
+		})
+		containerID = containerID + idrange.Length
+	}
+	return idMap
+}
+
+func parseSubuid(username string) (ranges, error) {
+	return parseSubidFile(subuidFileName, username)
+}
+
+func parseSubgid(username string) (ranges, error) {
+	return parseSubidFile(subgidFileName, username)
+}
+
+// parseSubidFile will read the appropriate file (/etc/subuid or /etc/subgid)
+// and return all found ranges for a specified username. If the special value
+// "ALL" is supplied for username, then all ranges in the file will be returned
+func parseSubidFile(path, username string) (ranges, error) {
+	var rangeList ranges
+
+	subidFile, err := os.Open(path)
+	if err != nil {
+		return rangeList, err
+	}
+	defer subidFile.Close()
+
+	s := bufio.NewScanner(subidFile)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return rangeList, err
+		}
+
+		text := strings.TrimSpace(s.Text())
+		if text == "" || strings.HasPrefix(text, "#") {
+			continue
+		}
+		parts := strings.Split(text, ":")
+		if len(parts) != 3 {
+			return rangeList, fmt.Errorf("Cannot parse subuid/gid information: Format not correct for %s file", path)
+		}
+		if parts[0] == username || username == "ALL" {
+			startid, err := strconv.Atoi(parts[1])
+			if err != nil {
+				return rangeList, fmt.Errorf("String to int conversion failed during subuid/gid parsing of %s: %v", path, err)
+			}
+			length, err := strconv.Atoi(parts[2])
+			if err != nil {
+				return rangeList, fmt.Errorf("String to int conversion failed during subuid/gid parsing of %s: %v", path, err)
+			}
+			rangeList = append(rangeList, subIDRange{startid, length})
+		}
+	}
+	return rangeList, nil
+}

vendor/github.com/docker/docker/pkg/idtools/idtools_unix.go

@@ -0,0 +1,204 @@
+// +build !windows
+
+package idtools
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/docker/docker/pkg/system"
+	"github.com/opencontainers/runc/libcontainer/user"
+)
+
+var (
+	entOnce   sync.Once
+	getentCmd string
+)
+
+func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error {
+	// make an array containing the original path asked for, plus (for mkAll == true)
+	// all path components leading up to the complete path that don't exist before we MkdirAll
+	// so that we can chown all of them properly at the end.  If chownExisting is false, we won't
+	// chown the full directory path if it exists
+	var paths []string
+	if _, err := os.Stat(path); err != nil && os.IsNotExist(err) {
+		paths = []string{path}
+	} else if err == nil && chownExisting {
+		// short-circuit--we were called with an existing directory and chown was requested
+		return os.Chown(path, ownerUID, ownerGID)
+	} else if err == nil {
+		// nothing to do; directory path fully exists already and chown was NOT requested
+		return nil
+	}
+
+	if mkAll {
+		// walk back to "/" looking for directories which do not exist
+		// and add them to the paths array for chown after creation
+		dirPath := path
+		for {
+			dirPath = filepath.Dir(dirPath)
+			if dirPath == "/" {
+				break
+			}
+			if _, err := os.Stat(dirPath); err != nil && os.IsNotExist(err) {
+				paths = append(paths, dirPath)
+			}
+		}
+		if err := system.MkdirAll(path, mode, ""); err != nil && !os.IsExist(err) {
+			return err
+		}
+	} else {
+		if err := os.Mkdir(path, mode); err != nil && !os.IsExist(err) {
+			return err
+		}
+	}
+	// even if it existed, we will chown the requested path + any subpaths that
+	// didn't exist when we called MkdirAll
+	for _, pathComponent := range paths {
+		if err := os.Chown(pathComponent, ownerUID, ownerGID); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// CanAccess takes a valid (existing) directory and a uid, gid pair and determines
+// if that uid, gid pair has access (execute bit) to the directory
+func CanAccess(path string, pair IDPair) bool {
+	statInfo, err := system.Stat(path)
+	if err != nil {
+		return false
+	}
+	fileMode := os.FileMode(statInfo.Mode())
+	permBits := fileMode.Perm()
+	return accessible(statInfo.UID() == uint32(pair.UID),
+		statInfo.GID() == uint32(pair.GID), permBits)
+}
+
+func accessible(isOwner, isGroup bool, perms os.FileMode) bool {
+	if isOwner && (perms&0100 == 0100) {
+		return true
+	}
+	if isGroup && (perms&0010 == 0010) {
+		return true
+	}
+	if perms&0001 == 0001 {
+		return true
+	}
+	return false
+}
+
+// LookupUser uses traditional local system files lookup (from libcontainer/user) on a username,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupUser(username string) (user.User, error) {
+	// first try a local system files lookup using existing capabilities
+	usr, err := user.LookupUser(username)
+	if err == nil {
+		return usr, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured passwd dbs
+	usr, err = getentUser(fmt.Sprintf("%s %s", "passwd", username))
+	if err != nil {
+		return user.User{}, err
+	}
+	return usr, nil
+}
+
+// LookupUID uses traditional local system files lookup (from libcontainer/user) on a uid,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupUID(uid int) (user.User, error) {
+	// first try a local system files lookup using existing capabilities
+	usr, err := user.LookupUid(uid)
+	if err == nil {
+		return usr, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured passwd dbs
+	return getentUser(fmt.Sprintf("%s %d", "passwd", uid))
+}
+
+func getentUser(args string) (user.User, error) {
+	reader, err := callGetent(args)
+	if err != nil {
+		return user.User{}, err
+	}
+	users, err := user.ParsePasswd(reader)
+	if err != nil {
+		return user.User{}, err
+	}
+	if len(users) == 0 {
+		return user.User{}, fmt.Errorf("getent failed to find passwd entry for %q", strings.Split(args, " ")[1])
+	}
+	return users[0], nil
+}
+
+// LookupGroup uses traditional local system files lookup (from libcontainer/user) on a group name,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupGroup(groupname string) (user.Group, error) {
+	// first try a local system files lookup using existing capabilities
+	group, err := user.LookupGroup(groupname)
+	if err == nil {
+		return group, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured group dbs
+	return getentGroup(fmt.Sprintf("%s %s", "group", groupname))
+}
+
+// LookupGID uses traditional local system files lookup (from libcontainer/user) on a group ID,
+// followed by a call to `getent` for supporting host configured non-files passwd and group dbs
+func LookupGID(gid int) (user.Group, error) {
+	// first try a local system files lookup using existing capabilities
+	group, err := user.LookupGid(gid)
+	if err == nil {
+		return group, nil
+	}
+	// local files lookup failed; attempt to call `getent` to query configured group dbs
+	return getentGroup(fmt.Sprintf("%s %d", "group", gid))
+}
+
+func getentGroup(args string) (user.Group, error) {
+	reader, err := callGetent(args)
+	if err != nil {
+		return user.Group{}, err
+	}
+	groups, err := user.ParseGroup(reader)
+	if err != nil {
+		return user.Group{}, err
+	}
+	if len(groups) == 0 {
+		return user.Group{}, fmt.Errorf("getent failed to find groups entry for %q", strings.Split(args, " ")[1])
+	}
+	return groups[0], nil
+}
+
+func callGetent(args string) (io.Reader, error) {
+	entOnce.Do(func() { getentCmd, _ = resolveBinary("getent") })
+	// if no `getent` command on host, can't do anything else
+	if getentCmd == "" {
+		return nil, fmt.Errorf("")
+	}
+	out, err := execCmd(getentCmd, args)
+	if err != nil {
+		exitCode, errC := system.GetExitCode(err)
+		if errC != nil {
+			return nil, err
+		}
+		switch exitCode {
+		case 1:
+			return nil, fmt.Errorf("getent reported invalid parameters/database unknown")
+		case 2:
+			terms := strings.Split(args, " ")
+			return nil, fmt.Errorf("getent unable to find entry %q in %s database", terms[1], terms[0])
+		case 3:
+			return nil, fmt.Errorf("getent database doesn't support enumeration")
+		default:
+			return nil, err
+		}
+
+	}
+	return bytes.NewReader(out), nil
+}

vendor/github.com/docker/docker/pkg/idtools/idtools_windows.go

@@ -0,0 +1,25 @@
+// +build windows
+
+package idtools
+
+import (
+	"os"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+// Platforms such as Windows do not support the UID/GID concept. So make this
+// just a wrapper around system.MkdirAll.
+func mkdirAs(path string, mode os.FileMode, ownerUID, ownerGID int, mkAll, chownExisting bool) error {
+	if err := system.MkdirAll(path, mode, ""); err != nil && !os.IsExist(err) {
+		return err
+	}
+	return nil
+}
+
+// CanAccess takes a valid (existing) directory and a uid, gid pair and determines
+// if that uid, gid pair has access (execute bit) to the directory
+// Windows does not require/support this function, so always return true
+func CanAccess(path string, pair IDPair) bool {
+	return true
+}

vendor/github.com/docker/docker/pkg/idtools/usergroupadd_linux.go

@@ -0,0 +1,164 @@
+package idtools
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// add a user and/or group to Linux /etc/passwd, /etc/group using standard
+// Linux distribution commands:
+// adduser --system --shell /bin/false --disabled-login --disabled-password --no-create-home --group <username>
+// useradd -r -s /bin/false <username>
+
+var (
+	once        sync.Once
+	userCommand string
+
+	cmdTemplates = map[string]string{
+		"adduser": "--system --shell /bin/false --no-create-home --disabled-login --disabled-password --group %s",
+		"useradd": "-r -s /bin/false %s",
+		"usermod": "-%s %d-%d %s",
+	}
+
+	idOutRegexp = regexp.MustCompile(`uid=([0-9]+).*gid=([0-9]+)`)
+	// default length for a UID/GID subordinate range
+	defaultRangeLen   = 65536
+	defaultRangeStart = 100000
+	userMod           = "usermod"
+)
+
+// AddNamespaceRangesUser takes a username and uses the standard system
+// utility to create a system user/group pair used to hold the
+// /etc/sub{uid,gid} ranges which will be used for user namespace
+// mapping ranges in containers.
+func AddNamespaceRangesUser(name string) (int, int, error) {
+	if err := addUser(name); err != nil {
+		return -1, -1, fmt.Errorf("Error adding user %q: %v", name, err)
+	}
+
+	// Query the system for the created uid and gid pair
+	out, err := execCmd("id", name)
+	if err != nil {
+		return -1, -1, fmt.Errorf("Error trying to find uid/gid for new user %q: %v", name, err)
+	}
+	matches := idOutRegexp.FindStringSubmatch(strings.TrimSpace(string(out)))
+	if len(matches) != 3 {
+		return -1, -1, fmt.Errorf("Can't find uid, gid from `id` output: %q", string(out))
+	}
+	uid, err := strconv.Atoi(matches[1])
+	if err != nil {
+		return -1, -1, fmt.Errorf("Can't convert found uid (%s) to int: %v", matches[1], err)
+	}
+	gid, err := strconv.Atoi(matches[2])
+	if err != nil {
+		return -1, -1, fmt.Errorf("Can't convert found gid (%s) to int: %v", matches[2], err)
+	}
+
+	// Now we need to create the subuid/subgid ranges for our new user/group (system users
+	// do not get auto-created ranges in subuid/subgid)
+
+	if err := createSubordinateRanges(name); err != nil {
+		return -1, -1, fmt.Errorf("Couldn't create subordinate ID ranges: %v", err)
+	}
+	return uid, gid, nil
+}
+
+func addUser(userName string) error {
+	once.Do(func() {
+		// set up which commands are used for adding users/groups dependent on distro
+		if _, err := resolveBinary("adduser"); err == nil {
+			userCommand = "adduser"
+		} else if _, err := resolveBinary("useradd"); err == nil {
+			userCommand = "useradd"
+		}
+	})
+	if userCommand == "" {
+		return fmt.Errorf("Cannot add user; no useradd/adduser binary found")
+	}
+	args := fmt.Sprintf(cmdTemplates[userCommand], userName)
+	out, err := execCmd(userCommand, args)
+	if err != nil {
+		return fmt.Errorf("Failed to add user with error: %v; output: %q", err, string(out))
+	}
+	return nil
+}
+
+func createSubordinateRanges(name string) error {
+
+	// first, we should verify that ranges weren't automatically created
+	// by the distro tooling
+	ranges, err := parseSubuid(name)
+	if err != nil {
+		return fmt.Errorf("Error while looking for subuid ranges for user %q: %v", name, err)
+	}
+	if len(ranges) == 0 {
+		// no UID ranges; let's create one
+		startID, err := findNextUIDRange()
+		if err != nil {
+			return fmt.Errorf("Can't find available subuid range: %v", err)
+		}
+		out, err := execCmd(userMod, fmt.Sprintf(cmdTemplates[userMod], "v", startID, startID+defaultRangeLen-1, name))
+		if err != nil {
+			return fmt.Errorf("Unable to add subuid range to user: %q; output: %s, err: %v", name, out, err)
+		}
+	}
+
+	ranges, err = parseSubgid(name)
+	if err != nil {
+		return fmt.Errorf("Error while looking for subgid ranges for user %q: %v", name, err)
+	}
+	if len(ranges) == 0 {
+		// no GID ranges; let's create one
+		startID, err := findNextGIDRange()
+		if err != nil {
+			return fmt.Errorf("Can't find available subgid range: %v", err)
+		}
+		out, err := execCmd(userMod, fmt.Sprintf(cmdTemplates[userMod], "w", startID, startID+defaultRangeLen-1, name))
+		if err != nil {
+			return fmt.Errorf("Unable to add subgid range to user: %q; output: %s, err: %v", name, out, err)
+		}
+	}
+	return nil
+}
+
+func findNextUIDRange() (int, error) {
+	ranges, err := parseSubuid("ALL")
+	if err != nil {
+		return -1, fmt.Errorf("Couldn't parse all ranges in /etc/subuid file: %v", err)
+	}
+	sort.Sort(ranges)
+	return findNextRangeStart(ranges)
+}
+
+func findNextGIDRange() (int, error) {
+	ranges, err := parseSubgid("ALL")
+	if err != nil {
+		return -1, fmt.Errorf("Couldn't parse all ranges in /etc/subgid file: %v", err)
+	}
+	sort.Sort(ranges)
+	return findNextRangeStart(ranges)
+}
+
+func findNextRangeStart(rangeList ranges) (int, error) {
+	startID := defaultRangeStart
+	for _, arange := range rangeList {
+		if wouldOverlap(arange, startID) {
+			startID = arange.Start + arange.Length
+		}
+	}
+	return startID, nil
+}
+
+func wouldOverlap(arange subIDRange, ID int) bool {
+	low := ID
+	high := ID + defaultRangeLen
+	if (low >= arange.Start && low <= arange.Start+arange.Length) ||
+		(high <= arange.Start+arange.Length && high >= arange.Start) {
+		return true
+	}
+	return false
+}

vendor/github.com/docker/docker/pkg/idtools/usergroupadd_unsupported.go

@@ -0,0 +1,12 @@
+// +build !linux
+
+package idtools
+
+import "fmt"
+
+// AddNamespaceRangesUser takes a name and finds an unused uid, gid pair
+// and calls the appropriate helper function to add the group and then
+// the user to the group in /etc/group and /etc/passwd respectively.
+func AddNamespaceRangesUser(name string) (int, int, error) {
+	return -1, -1, fmt.Errorf("No support for adding users or groups on this OS")
+}

vendor/github.com/docker/docker/pkg/idtools/utils_unix.go

@@ -0,0 +1,32 @@
+// +build !windows
+
+package idtools
+
+import (
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func resolveBinary(binname string) (string, error) {
+	binaryPath, err := exec.LookPath(binname)
+	if err != nil {
+		return "", err
+	}
+	resolvedPath, err := filepath.EvalSymlinks(binaryPath)
+	if err != nil {
+		return "", err
+	}
+	//only return no error if the final resolved binary basename
+	//matches what was searched for
+	if filepath.Base(resolvedPath) == binname {
+		return resolvedPath, nil
+	}
+	return "", fmt.Errorf("Binary %q does not resolve to a binary of that name in $PATH (%q)", binname, resolvedPath)
+}
+
+func execCmd(cmd, args string) ([]byte, error) {
+	execCmd := exec.Command(cmd, strings.Split(args, " ")...)
+	return execCmd.CombinedOutput()
+}

vendor/github.com/docker/docker/pkg/ioutils/buffer.go

@@ -0,0 +1,51 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+)
+
+var errBufferFull = errors.New("buffer is full")
+
+type fixedBuffer struct {
+	buf      []byte
+	pos      int
+	lastRead int
+}
+
+func (b *fixedBuffer) Write(p []byte) (int, error) {
+	n := copy(b.buf[b.pos:cap(b.buf)], p)
+	b.pos += n
+
+	if n < len(p) {
+		if b.pos == cap(b.buf) {
+			return n, errBufferFull
+		}
+		return n, io.ErrShortWrite
+	}
+	return n, nil
+}
+
+func (b *fixedBuffer) Read(p []byte) (int, error) {
+	n := copy(p, b.buf[b.lastRead:b.pos])
+	b.lastRead += n
+	return n, nil
+}
+
+func (b *fixedBuffer) Len() int {
+	return b.pos - b.lastRead
+}
+
+func (b *fixedBuffer) Cap() int {
+	return cap(b.buf)
+}
+
+func (b *fixedBuffer) Reset() {
+	b.pos = 0
+	b.lastRead = 0
+	b.buf = b.buf[:0]
+}
+
+func (b *fixedBuffer) String() string {
+	return string(b.buf[b.lastRead:b.pos])
+}

vendor/github.com/docker/docker/pkg/ioutils/bytespipe.go

@@ -0,0 +1,186 @@
+package ioutils
+
+import (
+	"errors"
+	"io"
+	"sync"
+)
+
+// maxCap is the highest capacity to use in byte slices that buffer data.
+const maxCap = 1e6
+
+// minCap is the lowest capacity to use in byte slices that buffer data
+const minCap = 64
+
+// blockThreshold is the minimum number of bytes in the buffer which will cause
+// a write to BytesPipe to block when allocating a new slice.
+const blockThreshold = 1e6
+
+var (
+	// ErrClosed is returned when Write is called on a closed BytesPipe.
+	ErrClosed = errors.New("write to closed BytesPipe")
+
+	bufPools     = make(map[int]*sync.Pool)
+	bufPoolsLock sync.Mutex
+)
+
+// BytesPipe is io.ReadWriteCloser which works similarly to pipe(queue).
+// All written data may be read at most once. Also, BytesPipe allocates
+// and releases new byte slices to adjust to current needs, so the buffer
+// won't be overgrown after peak loads.
+type BytesPipe struct {
+	mu       sync.Mutex
+	wait     *sync.Cond
+	buf      []*fixedBuffer
+	bufLen   int
+	closeErr error // error to return from next Read. set to nil if not closed.
+}
+
+// NewBytesPipe creates new BytesPipe, initialized by specified slice.
+// If buf is nil, then it will be initialized with slice which cap is 64.
+// buf will be adjusted in a way that len(buf) == 0, cap(buf) == cap(buf).
+func NewBytesPipe() *BytesPipe {
+	bp := &BytesPipe{}
+	bp.buf = append(bp.buf, getBuffer(minCap))
+	bp.wait = sync.NewCond(&bp.mu)
+	return bp
+}
+
+// Write writes p to BytesPipe.
+// It can allocate new []byte slices in a process of writing.
+func (bp *BytesPipe) Write(p []byte) (int, error) {
+	bp.mu.Lock()
+
+	written := 0
+loop0:
+	for {
+		if bp.closeErr != nil {
+			bp.mu.Unlock()
+			return written, ErrClosed
+		}
+
+		if len(bp.buf) == 0 {
+			bp.buf = append(bp.buf, getBuffer(64))
+		}
+		// get the last buffer
+		b := bp.buf[len(bp.buf)-1]
+
+		n, err := b.Write(p)
+		written += n
+		bp.bufLen += n
+
+		// errBufferFull is an error we expect to get if the buffer is full
+		if err != nil && err != errBufferFull {
+			bp.wait.Broadcast()
+			bp.mu.Unlock()
+			return written, err
+		}
+
+		// if there was enough room to write all then break
+		if len(p) == n {
+			break
+		}
+
+		// more data: write to the next slice
+		p = p[n:]
+
+		// make sure the buffer doesn't grow too big from this write
+		for bp.bufLen >= blockThreshold {
+			bp.wait.Wait()
+			if bp.closeErr != nil {
+				continue loop0
+			}
+		}
+
+		// add new byte slice to the buffers slice and continue writing
+		nextCap := b.Cap() * 2
+		if nextCap > maxCap {
+			nextCap = maxCap
+		}
+		bp.buf = append(bp.buf, getBuffer(nextCap))
+	}
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return written, nil
+}
+
+// CloseWithError causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) CloseWithError(err error) error {
+	bp.mu.Lock()
+	if err != nil {
+		bp.closeErr = err
+	} else {
+		bp.closeErr = io.EOF
+	}
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return nil
+}
+
+// Close causes further reads from a BytesPipe to return immediately.
+func (bp *BytesPipe) Close() error {
+	return bp.CloseWithError(nil)
+}
+
+// Read reads bytes from BytesPipe.
+// Data could be read only once.
+func (bp *BytesPipe) Read(p []byte) (n int, err error) {
+	bp.mu.Lock()
+	if bp.bufLen == 0 {
+		if bp.closeErr != nil {
+			bp.mu.Unlock()
+			return 0, bp.closeErr
+		}
+		bp.wait.Wait()
+		if bp.bufLen == 0 && bp.closeErr != nil {
+			err := bp.closeErr
+			bp.mu.Unlock()
+			return 0, err
+		}
+	}
+
+	for bp.bufLen > 0 {
+		b := bp.buf[0]
+		read, _ := b.Read(p) // ignore error since fixedBuffer doesn't really return an error
+		n += read
+		bp.bufLen -= read
+
+		if b.Len() == 0 {
+			// it's empty so return it to the pool and move to the next one
+			returnBuffer(b)
+			bp.buf[0] = nil
+			bp.buf = bp.buf[1:]
+		}
+
+		if len(p) == read {
+			break
+		}
+
+		p = p[read:]
+	}
+
+	bp.wait.Broadcast()
+	bp.mu.Unlock()
+	return
+}
+
+func returnBuffer(b *fixedBuffer) {
+	b.Reset()
+	bufPoolsLock.Lock()
+	pool := bufPools[b.Cap()]
+	bufPoolsLock.Unlock()
+	if pool != nil {
+		pool.Put(b)
+	}
+}
+
+func getBuffer(size int) *fixedBuffer {
+	bufPoolsLock.Lock()
+	pool, ok := bufPools[size]
+	if !ok {
+		pool = &sync.Pool{New: func() interface{} { return &fixedBuffer{buf: make([]byte, 0, size)} }}
+		bufPools[size] = pool
+	}
+	bufPoolsLock.Unlock()
+	return pool.Get().(*fixedBuffer)
+}

vendor/github.com/docker/docker/pkg/ioutils/fswriters.go

@@ -0,0 +1,162 @@
+package ioutils
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// NewAtomicFileWriter returns WriteCloser so that writing to it writes to a
+// temporary file and closing it atomically changes the temporary file to
+// destination path. Writing and closing concurrently is not allowed.
+func NewAtomicFileWriter(filename string, perm os.FileMode) (io.WriteCloser, error) {
+	f, err := ioutil.TempFile(filepath.Dir(filename), ".tmp-"+filepath.Base(filename))
+	if err != nil {
+		return nil, err
+	}
+
+	abspath, err := filepath.Abs(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &atomicFileWriter{
+		f:    f,
+		fn:   abspath,
+		perm: perm,
+	}, nil
+}
+
+// AtomicWriteFile atomically writes data to a file named by filename.
+func AtomicWriteFile(filename string, data []byte, perm os.FileMode) error {
+	f, err := NewAtomicFileWriter(filename, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+		f.(*atomicFileWriter).writeErr = err
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+type atomicFileWriter struct {
+	f        *os.File
+	fn       string
+	writeErr error
+	perm     os.FileMode
+}
+
+func (w *atomicFileWriter) Write(dt []byte) (int, error) {
+	n, err := w.f.Write(dt)
+	if err != nil {
+		w.writeErr = err
+	}
+	return n, err
+}
+
+func (w *atomicFileWriter) Close() (retErr error) {
+	defer func() {
+		if retErr != nil || w.writeErr != nil {
+			os.Remove(w.f.Name())
+		}
+	}()
+	if err := w.f.Sync(); err != nil {
+		w.f.Close()
+		return err
+	}
+	if err := w.f.Close(); err != nil {
+		return err
+	}
+	if err := os.Chmod(w.f.Name(), w.perm); err != nil {
+		return err
+	}
+	if w.writeErr == nil {
+		return os.Rename(w.f.Name(), w.fn)
+	}
+	return nil
+}
+
+// AtomicWriteSet is used to atomically write a set
+// of files and ensure they are visible at the same time.
+// Must be committed to a new directory.
+type AtomicWriteSet struct {
+	root string
+}
+
+// NewAtomicWriteSet creates a new atomic write set to
+// atomically create a set of files. The given directory
+// is used as the base directory for storing files before
+// commit. If no temporary directory is given the system
+// default is used.
+func NewAtomicWriteSet(tmpDir string) (*AtomicWriteSet, error) {
+	td, err := ioutil.TempDir(tmpDir, "write-set-")
+	if err != nil {
+		return nil, err
+	}
+
+	return &AtomicWriteSet{
+		root: td,
+	}, nil
+}
+
+// WriteFile writes a file to the set, guaranteeing the file
+// has been synced.
+func (ws *AtomicWriteSet) WriteFile(filename string, data []byte, perm os.FileMode) error {
+	f, err := ws.FileWriter(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+type syncFileCloser struct {
+	*os.File
+}
+
+func (w syncFileCloser) Close() error {
+	err := w.File.Sync()
+	if err1 := w.File.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+// FileWriter opens a file writer inside the set. The file
+// should be synced and closed before calling commit.
+func (ws *AtomicWriteSet) FileWriter(name string, flag int, perm os.FileMode) (io.WriteCloser, error) {
+	f, err := os.OpenFile(filepath.Join(ws.root, name), flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	return syncFileCloser{f}, nil
+}
+
+// Cancel cancels the set and removes all temporary data
+// created in the set.
+func (ws *AtomicWriteSet) Cancel() error {
+	return os.RemoveAll(ws.root)
+}
+
+// Commit moves all created files to the target directory. The
+// target directory must not exist and the parent of the target
+// directory must exist.
+func (ws *AtomicWriteSet) Commit(target string) error {
+	return os.Rename(ws.root, target)
+}
+
+// String returns the location the set is writing to.
+func (ws *AtomicWriteSet) String() string {
+	return ws.root
+}

vendor/github.com/docker/docker/pkg/ioutils/readers.go

@@ -0,0 +1,154 @@
+package ioutils
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+
+	"golang.org/x/net/context"
+)
+
+type readCloserWrapper struct {
+	io.Reader
+	closer func() error
+}
+
+func (r *readCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewReadCloserWrapper returns a new io.ReadCloser.
+func NewReadCloserWrapper(r io.Reader, closer func() error) io.ReadCloser {
+	return &readCloserWrapper{
+		Reader: r,
+		closer: closer,
+	}
+}
+
+type readerErrWrapper struct {
+	reader io.Reader
+	closer func()
+}
+
+func (r *readerErrWrapper) Read(p []byte) (int, error) {
+	n, err := r.reader.Read(p)
+	if err != nil {
+		r.closer()
+	}
+	return n, err
+}
+
+// NewReaderErrWrapper returns a new io.Reader.
+func NewReaderErrWrapper(r io.Reader, closer func()) io.Reader {
+	return &readerErrWrapper{
+		reader: r,
+		closer: closer,
+	}
+}
+
+// HashData returns the sha256 sum of src.
+func HashData(src io.Reader) (string, error) {
+	h := sha256.New()
+	if _, err := io.Copy(h, src); err != nil {
+		return "", err
+	}
+	return "sha256:" + hex.EncodeToString(h.Sum(nil)), nil
+}
+
+// OnEOFReader wraps an io.ReadCloser and a function
+// the function will run at the end of file or close the file.
+type OnEOFReader struct {
+	Rc io.ReadCloser
+	Fn func()
+}
+
+func (r *OnEOFReader) Read(p []byte) (n int, err error) {
+	n, err = r.Rc.Read(p)
+	if err == io.EOF {
+		r.runFunc()
+	}
+	return
+}
+
+// Close closes the file and run the function.
+func (r *OnEOFReader) Close() error {
+	err := r.Rc.Close()
+	r.runFunc()
+	return err
+}
+
+func (r *OnEOFReader) runFunc() {
+	if fn := r.Fn; fn != nil {
+		fn()
+		r.Fn = nil
+	}
+}
+
+// cancelReadCloser wraps an io.ReadCloser with a context for cancelling read
+// operations.
+type cancelReadCloser struct {
+	cancel func()
+	pR     *io.PipeReader // Stream to read from
+	pW     *io.PipeWriter
+}
+
+// NewCancelReadCloser creates a wrapper that closes the ReadCloser when the
+// context is cancelled. The returned io.ReadCloser must be closed when it is
+// no longer needed.
+func NewCancelReadCloser(ctx context.Context, in io.ReadCloser) io.ReadCloser {
+	pR, pW := io.Pipe()
+
+	// Create a context used to signal when the pipe is closed
+	doneCtx, cancel := context.WithCancel(context.Background())
+
+	p := &cancelReadCloser{
+		cancel: cancel,
+		pR:     pR,
+		pW:     pW,
+	}
+
+	go func() {
+		_, err := io.Copy(pW, in)
+		select {
+		case <-ctx.Done():
+			// If the context was closed, p.closeWithError
+			// was already called. Calling it again would
+			// change the error that Read returns.
+		default:
+			p.closeWithError(err)
+		}
+		in.Close()
+	}()
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				p.closeWithError(ctx.Err())
+			case <-doneCtx.Done():
+				return
+			}
+		}
+	}()
+
+	return p
+}
+
+// Read wraps the Read method of the pipe that provides data from the wrapped
+// ReadCloser.
+func (p *cancelReadCloser) Read(buf []byte) (n int, err error) {
+	return p.pR.Read(buf)
+}
+
+// closeWithError closes the wrapper and its underlying reader. It will
+// cause future calls to Read to return err.
+func (p *cancelReadCloser) closeWithError(err error) {
+	p.pW.CloseWithError(err)
+	p.cancel()
+}
+
+// Close closes the wrapper its underlying reader. It will cause
+// future calls to Read to return io.EOF.
+func (p *cancelReadCloser) Close() error {
+	p.closeWithError(io.EOF)
+	return nil
+}

vendor/github.com/docker/docker/pkg/ioutils/temp_unix.go

@@ -0,0 +1,10 @@
+// +build !windows
+
+package ioutils
+
+import "io/ioutil"
+
+// TempDir on Unix systems is equivalent to ioutil.TempDir.
+func TempDir(dir, prefix string) (string, error) {
+	return ioutil.TempDir(dir, prefix)
+}

vendor/github.com/docker/docker/pkg/ioutils/temp_windows.go

@@ -0,0 +1,18 @@
+// +build windows
+
+package ioutils
+
+import (
+	"io/ioutil"
+
+	"github.com/docker/docker/pkg/longpath"
+)
+
+// TempDir is the equivalent of ioutil.TempDir, except that the result is in Windows longpath format.
+func TempDir(dir, prefix string) (string, error) {
+	tempDir, err := ioutil.TempDir(dir, prefix)
+	if err != nil {
+		return "", err
+	}
+	return longpath.AddPrefix(tempDir), nil
+}

vendor/github.com/docker/docker/pkg/ioutils/writeflusher.go

@@ -0,0 +1,92 @@
+package ioutils
+
+import (
+	"io"
+	"sync"
+)
+
+// WriteFlusher wraps the Write and Flush operation ensuring that every write
+// is a flush. In addition, the Close method can be called to intercept
+// Read/Write calls if the targets lifecycle has already ended.
+type WriteFlusher struct {
+	w           io.Writer
+	flusher     flusher
+	flushed     chan struct{}
+	flushedOnce sync.Once
+	closed      chan struct{}
+	closeLock   sync.Mutex
+}
+
+type flusher interface {
+	Flush()
+}
+
+var errWriteFlusherClosed = io.EOF
+
+func (wf *WriteFlusher) Write(b []byte) (n int, err error) {
+	select {
+	case <-wf.closed:
+		return 0, errWriteFlusherClosed
+	default:
+	}
+
+	n, err = wf.w.Write(b)
+	wf.Flush() // every write is a flush.
+	return n, err
+}
+
+// Flush the stream immediately.
+func (wf *WriteFlusher) Flush() {
+	select {
+	case <-wf.closed:
+		return
+	default:
+	}
+
+	wf.flushedOnce.Do(func() {
+		close(wf.flushed)
+	})
+	wf.flusher.Flush()
+}
+
+// Flushed returns the state of flushed.
+// If it's flushed, return true, or else it return false.
+func (wf *WriteFlusher) Flushed() bool {
+	// BUG(stevvooe): Remove this method. Its use is inherently racy. Seems to
+	// be used to detect whether or a response code has been issued or not.
+	// Another hook should be used instead.
+	var flushed bool
+	select {
+	case <-wf.flushed:
+		flushed = true
+	default:
+	}
+	return flushed
+}
+
+// Close closes the write flusher, disallowing any further writes to the
+// target. After the flusher is closed, all calls to write or flush will
+// result in an error.
+func (wf *WriteFlusher) Close() error {
+	wf.closeLock.Lock()
+	defer wf.closeLock.Unlock()
+
+	select {
+	case <-wf.closed:
+		return errWriteFlusherClosed
+	default:
+		close(wf.closed)
+	}
+	return nil
+}
+
+// NewWriteFlusher returns a new WriteFlusher.
+func NewWriteFlusher(w io.Writer) *WriteFlusher {
+	var fl flusher
+	if f, ok := w.(flusher); ok {
+		fl = f
+	} else {
+		fl = &NopFlusher{}
+	}
+	return &WriteFlusher{w: w, flusher: fl, closed: make(chan struct{}), flushed: make(chan struct{})}
+}

vendor/github.com/docker/docker/pkg/ioutils/writers.go

@@ -0,0 +1,66 @@
+package ioutils
+
+import "io"
+
+// NopWriter represents a type which write operation is nop.
+type NopWriter struct{}
+
+func (*NopWriter) Write(buf []byte) (int, error) {
+	return len(buf), nil
+}
+
+type nopWriteCloser struct {
+	io.Writer
+}
+
+func (w *nopWriteCloser) Close() error { return nil }
+
+// NopWriteCloser returns a nopWriteCloser.
+func NopWriteCloser(w io.Writer) io.WriteCloser {
+	return &nopWriteCloser{w}
+}
+
+// NopFlusher represents a type which flush operation is nop.
+type NopFlusher struct{}
+
+// Flush is a nop operation.
+func (f *NopFlusher) Flush() {}
+
+type writeCloserWrapper struct {
+	io.Writer
+	closer func() error
+}
+
+func (r *writeCloserWrapper) Close() error {
+	return r.closer()
+}
+
+// NewWriteCloserWrapper returns a new io.WriteCloser.
+func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {
+	return &writeCloserWrapper{
+		Writer: r,
+		closer: closer,
+	}
+}
+
+// WriteCounter wraps a concrete io.Writer and hold a count of the number
+// of bytes written to the writer during a "session".
+// This can be convenient when write return is masked
+// (e.g., json.Encoder.Encode())
+type WriteCounter struct {
+	Count  int64
+	Writer io.Writer
+}
+
+// NewWriteCounter returns a new WriteCounter.
+func NewWriteCounter(w io.Writer) *WriteCounter {
+	return &WriteCounter{
+		Writer: w,
+	}
+}
+
+func (wc *WriteCounter) Write(p []byte) (count int, err error) {
+	count, err = wc.Writer.Write(p)
+	wc.Count += int64(count)
+	return
+}

vendor/github.com/docker/docker/pkg/pools/pools.go

@@ -0,0 +1,137 @@
+// Package pools provides a collection of pools which provide various
+// data types with buffers. These can be used to lower the number of
+// memory allocations and reuse buffers.
+//
+// New pools should be added to this package to allow them to be
+// shared across packages.
+//
+// Utility functions which operate on pools should be added to this
+// package to allow them to be reused.
+package pools
+
+import (
+	"bufio"
+	"io"
+	"sync"
+
+	"github.com/docker/docker/pkg/ioutils"
+)
+
+const buffer32K = 32 * 1024
+
+var (
+	// BufioReader32KPool is a pool which returns bufio.Reader with a 32K buffer.
+	BufioReader32KPool = newBufioReaderPoolWithSize(buffer32K)
+	// BufioWriter32KPool is a pool which returns bufio.Writer with a 32K buffer.
+	BufioWriter32KPool = newBufioWriterPoolWithSize(buffer32K)
+	buffer32KPool      = newBufferPoolWithSize(buffer32K)
+)
+
+// BufioReaderPool is a bufio reader that uses sync.Pool.
+type BufioReaderPool struct {
+	pool sync.Pool
+}
+
+// newBufioReaderPoolWithSize is unexported because new pools should be
+// added here to be shared where required.
+func newBufioReaderPoolWithSize(size int) *BufioReaderPool {
+	return &BufioReaderPool{
+		pool: sync.Pool{
+			New: func() interface{} { return bufio.NewReaderSize(nil, size) },
+		},
+	}
+}
+
+// Get returns a bufio.Reader which reads from r. The buffer size is that of the pool.
+func (bufPool *BufioReaderPool) Get(r io.Reader) *bufio.Reader {
+	buf := bufPool.pool.Get().(*bufio.Reader)
+	buf.Reset(r)
+	return buf
+}
+
+// Put puts the bufio.Reader back into the pool.
+func (bufPool *BufioReaderPool) Put(b *bufio.Reader) {
+	b.Reset(nil)
+	bufPool.pool.Put(b)
+}
+
+type bufferPool struct {
+	pool sync.Pool
+}
+
+func newBufferPoolWithSize(size int) *bufferPool {
+	return &bufferPool{
+		pool: sync.Pool{
+			New: func() interface{} { return make([]byte, size) },
+		},
+	}
+}
+
+func (bp *bufferPool) Get() []byte {
+	return bp.pool.Get().([]byte)
+}
+
+func (bp *bufferPool) Put(b []byte) {
+	bp.pool.Put(b)
+}
+
+// Copy is a convenience wrapper which uses a buffer to avoid allocation in io.Copy.
+func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
+	buf := buffer32KPool.Get()
+	written, err = io.CopyBuffer(dst, src, buf)
+	buffer32KPool.Put(buf)
+	return
+}
+
+// NewReadCloserWrapper returns a wrapper which puts the bufio.Reader back
+// into the pool and closes the reader if it's an io.ReadCloser.
+func (bufPool *BufioReaderPool) NewReadCloserWrapper(buf *bufio.Reader, r io.Reader) io.ReadCloser {
+	return ioutils.NewReadCloserWrapper(r, func() error {
+		if readCloser, ok := r.(io.ReadCloser); ok {
+			readCloser.Close()
+		}
+		bufPool.Put(buf)
+		return nil
+	})
+}
+
+// BufioWriterPool is a bufio writer that uses sync.Pool.
+type BufioWriterPool struct {
+	pool sync.Pool
+}
+
+// newBufioWriterPoolWithSize is unexported because new pools should be
+// added here to be shared where required.
+func newBufioWriterPoolWithSize(size int) *BufioWriterPool {
+	return &BufioWriterPool{
+		pool: sync.Pool{
+			New: func() interface{} { return bufio.NewWriterSize(nil, size) },
+		},
+	}
+}
+
+// Get returns a bufio.Writer which writes to w. The buffer size is that of the pool.
+func (bufPool *BufioWriterPool) Get(w io.Writer) *bufio.Writer {
+	buf := bufPool.pool.Get().(*bufio.Writer)
+	buf.Reset(w)
+	return buf
+}
+
+// Put puts the bufio.Writer back into the pool.
+func (bufPool *BufioWriterPool) Put(b *bufio.Writer) {
+	b.Reset(nil)
+	bufPool.pool.Put(b)
+}
+
+// NewWriteCloserWrapper returns a wrapper which puts the bufio.Writer back
+// into the pool and closes the writer if it's an io.Writecloser.
+func (bufPool *BufioWriterPool) NewWriteCloserWrapper(buf *bufio.Writer, w io.Writer) io.WriteCloser {
+	return ioutils.NewWriteCloserWrapper(w, func() error {
+		buf.Flush()
+		if writeCloser, ok := w.(io.WriteCloser); ok {
+			writeCloser.Close()
+		}
+		bufPool.Put(buf)
+		return nil
+	})
+}

vendor/github.com/docker/docker/pkg/promise/promise.go

@@ -0,0 +1,11 @@
+package promise
+
+// Go is a basic promise implementation: it wraps calls a function in a goroutine,
+// and returns a channel which will later return the function's return value.
+func Go(f func() error) chan error {
+	ch := make(chan error, 1)
+	go func() {
+		ch <- f()
+	}()
+	return ch
+}

vendor/github.com/docker/docker/pkg/reexec/README.md

@@ -0,0 +1,5 @@
+# reexec
+
+The `reexec` package facilitates the busybox style reexec of the docker binary that we require because 
+of the forking limitations of using Go.  Handlers can be registered with a name and the argv 0 of 
+the exec of the binary will be used to find and execute custom init paths.

vendor/github.com/docker/docker/pkg/reexec/command_linux.go

@@ -0,0 +1,28 @@
+// +build linux
+
+package reexec
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+// Self returns the path to the current process's binary.
+// Returns "/proc/self/exe".
+func Self() string {
+	return "/proc/self/exe"
+}
+
+// Command returns *exec.Cmd which has Path as current binary. Also it setting
+// SysProcAttr.Pdeathsig to SIGTERM.
+// This will use the in-memory version (/proc/self/exe) of the current binary,
+// it is thus safe to delete or replace the on-disk binary (os.Args[0]).
+func Command(args ...string) *exec.Cmd {
+	return &exec.Cmd{
+		Path: Self(),
+		Args: args,
+		SysProcAttr: &syscall.SysProcAttr{
+			Pdeathsig: syscall.SIGTERM,
+		},
+	}
+}

vendor/github.com/docker/docker/pkg/reexec/command_unix.go

@@ -0,0 +1,23 @@
+// +build freebsd solaris darwin
+
+package reexec
+
+import (
+	"os/exec"
+)
+
+// Self returns the path to the current process's binary.
+// Uses os.Args[0].
+func Self() string {
+	return naiveSelf()
+}
+
+// Command returns *exec.Cmd which has Path as current binary.
+// For example if current binary is "docker" at "/usr/bin/", then cmd.Path will
+// be set to "/usr/bin/docker".
+func Command(args ...string) *exec.Cmd {
+	return &exec.Cmd{
+		Path: Self(),
+		Args: args,
+	}
+}

vendor/github.com/docker/docker/pkg/reexec/command_unsupported.go

@@ -0,0 +1,12 @@
+// +build !linux,!windows,!freebsd,!solaris,!darwin
+
+package reexec
+
+import (
+	"os/exec"
+)
+
+// Command is unsupported on operating systems apart from Linux, Windows, Solaris and Darwin.
+func Command(args ...string) *exec.Cmd {
+	return nil
+}

vendor/github.com/docker/docker/pkg/reexec/command_windows.go

@@ -0,0 +1,23 @@
+// +build windows
+
+package reexec
+
+import (
+	"os/exec"
+)
+
+// Self returns the path to the current process's binary.
+// Uses os.Args[0].
+func Self() string {
+	return naiveSelf()
+}
+
+// Command returns *exec.Cmd which has Path as current binary.
+// For example if current binary is "docker.exe" at "C:\", then cmd.Path will
+// be set to "C:\docker.exe".
+func Command(args ...string) *exec.Cmd {
+	return &exec.Cmd{
+		Path: Self(),
+		Args: args,
+	}
+}

vendor/github.com/docker/docker/pkg/reexec/reexec.go

@@ -0,0 +1,47 @@
+package reexec
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+var registeredInitializers = make(map[string]func())
+
+// Register adds an initialization func under the specified name
+func Register(name string, initializer func()) {
+	if _, exists := registeredInitializers[name]; exists {
+		panic(fmt.Sprintf("reexec func already registered under name %q", name))
+	}
+
+	registeredInitializers[name] = initializer
+}
+
+// Init is called as the first part of the exec process and returns true if an
+// initialization function was called.
+func Init() bool {
+	initializer, exists := registeredInitializers[os.Args[0]]
+	if exists {
+		initializer()
+
+		return true
+	}
+	return false
+}
+
+func naiveSelf() string {
+	name := os.Args[0]
+	if filepath.Base(name) == name {
+		if lp, err := exec.LookPath(name); err == nil {
+			return lp
+		}
+	}
+	// handle conversion of relative paths to absolute
+	if absName, err := filepath.Abs(name); err == nil {
+		return absName
+	}
+	// if we couldn't get absolute name, return original
+	// (NOTE: Go only errors on Abs() if os.Getwd fails)
+	return name
+}

vendor/github.com/docker/docker/pkg/stringid/README.md

@@ -0,0 +1 @@
+This package provides helper functions for dealing with string identifiers

vendor/github.com/docker/docker/pkg/stringid/stringid.go

@@ -0,0 +1,99 @@
+// Package stringid provides helper functions for dealing with string identifiers
+package stringid
+
+import (
+	cryptorand "crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"math"
+	"math/big"
+	"math/rand"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const shortLen = 12
+
+var (
+	validShortID = regexp.MustCompile("^[a-f0-9]{12}$")
+	validHex     = regexp.MustCompile(`^[a-f0-9]{64}$`)
+)
+
+// IsShortID determines if an arbitrary string *looks like* a short ID.
+func IsShortID(id string) bool {
+	return validShortID.MatchString(id)
+}
+
+// TruncateID returns a shorthand version of a string identifier for convenience.
+// A collision with other shorthands is very unlikely, but possible.
+// In case of a collision a lookup with TruncIndex.Get() will fail, and the caller
+// will need to use a longer prefix, or the full-length Id.
+func TruncateID(id string) string {
+	if i := strings.IndexRune(id, ':'); i >= 0 {
+		id = id[i+1:]
+	}
+	if len(id) > shortLen {
+		id = id[:shortLen]
+	}
+	return id
+}
+
+func generateID(r io.Reader) string {
+	b := make([]byte, 32)
+	for {
+		if _, err := io.ReadFull(r, b); err != nil {
+			panic(err) // This shouldn't happen
+		}
+		id := hex.EncodeToString(b)
+		// if we try to parse the truncated for as an int and we don't have
+		// an error then the value is all numeric and causes issues when
+		// used as a hostname. ref #3869
+		if _, err := strconv.ParseInt(TruncateID(id), 10, 64); err == nil {
+			continue
+		}
+		return id
+	}
+}
+
+// GenerateRandomID returns a unique id.
+func GenerateRandomID() string {
+	return generateID(cryptorand.Reader)
+}
+
+// GenerateNonCryptoID generates unique id without using cryptographically
+// secure sources of random.
+// It helps you to save entropy.
+func GenerateNonCryptoID() string {
+	return generateID(readerFunc(rand.Read))
+}
+
+// ValidateID checks whether an ID string is a valid image ID.
+func ValidateID(id string) error {
+	if ok := validHex.MatchString(id); !ok {
+		return fmt.Errorf("image ID %q is invalid", id)
+	}
+	return nil
+}
+
+func init() {
+	// safely set the seed globally so we generate random ids. Tries to use a
+	// crypto seed before falling back to time.
+	var seed int64
+	if cryptoseed, err := cryptorand.Int(cryptorand.Reader, big.NewInt(math.MaxInt64)); err != nil {
+		// This should not happen, but worst-case fallback to time-based seed.
+		seed = time.Now().UnixNano()
+	} else {
+		seed = cryptoseed.Int64()
+	}
+
+	rand.Seed(seed)
+}
+
+type readerFunc func(p []byte) (int, error)
+
+func (fn readerFunc) Read(p []byte) (int, error) {
+	return fn(p)
+}

vendor/github.com/docker/docker/pkg/tarsum/builder_context.go

@@ -0,0 +1,21 @@
+package tarsum
+
+// BuilderContext is an interface extending TarSum by adding the Remove method.
+// In general there was concern about adding this method to TarSum itself
+// so instead it is being added just to "BuilderContext" which will then
+// only be used during the .dockerignore file processing
+// - see builder/evaluator.go
+type BuilderContext interface {
+	TarSum
+	Remove(string)
+}
+
+func (bc *tarSum) Remove(filename string) {
+	for i, fis := range bc.sums {
+		if fis.Name() == filename {
+			bc.sums = append(bc.sums[:i], bc.sums[i+1:]...)
+			// Note, we don't just return because there could be
+			// more than one with this name
+		}
+	}
+}

vendor/github.com/docker/docker/pkg/tarsum/fileinfosums.go

@@ -0,0 +1,126 @@
+package tarsum
+
+import "sort"
+
+// FileInfoSumInterface provides an interface for accessing file checksum
+// information within a tar file. This info is accessed through interface
+// so the actual name and sum cannot be melded with.
+type FileInfoSumInterface interface {
+	// File name
+	Name() string
+	// Checksum of this particular file and its headers
+	Sum() string
+	// Position of file in the tar
+	Pos() int64
+}
+
+type fileInfoSum struct {
+	name string
+	sum  string
+	pos  int64
+}
+
+func (fis fileInfoSum) Name() string {
+	return fis.name
+}
+func (fis fileInfoSum) Sum() string {
+	return fis.sum
+}
+func (fis fileInfoSum) Pos() int64 {
+	return fis.pos
+}
+
+// FileInfoSums provides a list of FileInfoSumInterfaces.
+type FileInfoSums []FileInfoSumInterface
+
+// GetFile returns the first FileInfoSumInterface with a matching name.
+func (fis FileInfoSums) GetFile(name string) FileInfoSumInterface {
+	for i := range fis {
+		if fis[i].Name() == name {
+			return fis[i]
+		}
+	}
+	return nil
+}
+
+// GetAllFile returns a FileInfoSums with all matching names.
+func (fis FileInfoSums) GetAllFile(name string) FileInfoSums {
+	f := FileInfoSums{}
+	for i := range fis {
+		if fis[i].Name() == name {
+			f = append(f, fis[i])
+		}
+	}
+	return f
+}
+
+// GetDuplicatePaths returns a FileInfoSums with all duplicated paths.
+func (fis FileInfoSums) GetDuplicatePaths() (dups FileInfoSums) {
+	seen := make(map[string]int, len(fis)) // allocate earl. no need to grow this map.
+	for i := range fis {
+		f := fis[i]
+		if _, ok := seen[f.Name()]; ok {
+			dups = append(dups, f)
+		} else {
+			seen[f.Name()] = 0
+		}
+	}
+	return dups
+}
+
+// Len returns the size of the FileInfoSums.
+func (fis FileInfoSums) Len() int { return len(fis) }
+
+// Swap swaps two FileInfoSum values if a FileInfoSums list.
+func (fis FileInfoSums) Swap(i, j int) { fis[i], fis[j] = fis[j], fis[i] }
+
+// SortByPos sorts FileInfoSums content by position.
+func (fis FileInfoSums) SortByPos() {
+	sort.Sort(byPos{fis})
+}
+
+// SortByNames sorts FileInfoSums content by name.
+func (fis FileInfoSums) SortByNames() {
+	sort.Sort(byName{fis})
+}
+
+// SortBySums sorts FileInfoSums content by sums.
+func (fis FileInfoSums) SortBySums() {
+	dups := fis.GetDuplicatePaths()
+	if len(dups) > 0 {
+		sort.Sort(bySum{fis, dups})
+	} else {
+		sort.Sort(bySum{fis, nil})
+	}
+}
+
+// byName is a sort.Sort helper for sorting by file names.
+// If names are the same, order them by their appearance in the tar archive
+type byName struct{ FileInfoSums }
+
+func (bn byName) Less(i, j int) bool {
+	if bn.FileInfoSums[i].Name() == bn.FileInfoSums[j].Name() {
+		return bn.FileInfoSums[i].Pos() < bn.FileInfoSums[j].Pos()
+	}
+	return bn.FileInfoSums[i].Name() < bn.FileInfoSums[j].Name()
+}
+
+// bySum is a sort.Sort helper for sorting by the sums of all the fileinfos in the tar archive
+type bySum struct {
+	FileInfoSums
+	dups FileInfoSums
+}
+
+func (bs bySum) Less(i, j int) bool {
+	if bs.dups != nil && bs.FileInfoSums[i].Name() == bs.FileInfoSums[j].Name() {
+		return bs.FileInfoSums[i].Pos() < bs.FileInfoSums[j].Pos()
+	}
+	return bs.FileInfoSums[i].Sum() < bs.FileInfoSums[j].Sum()
+}
+
+// byPos is a sort.Sort helper for sorting by the sums of all the fileinfos by their original order
+type byPos struct{ FileInfoSums }
+
+func (bp byPos) Less(i, j int) bool {
+	return bp.FileInfoSums[i].Pos() < bp.FileInfoSums[j].Pos()
+}

vendor/github.com/docker/docker/pkg/tarsum/tarsum.go

@@ -0,0 +1,295 @@
+// Package tarsum provides algorithms to perform checksum calculation on
+// filesystem layers.
+//
+// The transportation of filesystems, regarding Docker, is done with tar(1)
+// archives. There are a variety of tar serialization formats [2], and a key
+// concern here is ensuring a repeatable checksum given a set of inputs from a
+// generic tar archive. Types of transportation include distribution to and from a
+// registry endpoint, saving and loading through commands or Docker daemon APIs,
+// transferring the build context from client to Docker daemon, and committing the
+// filesystem of a container to become an image.
+//
+// As tar archives are used for transit, but not preserved in many situations, the
+// focus of the algorithm is to ensure the integrity of the preserved filesystem,
+// while maintaining a deterministic accountability. This includes neither
+// constraining the ordering or manipulation of the files during the creation or
+// unpacking of the archive, nor include additional metadata state about the file
+// system attributes.
+package tarsum
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"crypto"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"hash"
+	"io"
+	"path"
+	"strings"
+)
+
+const (
+	buf8K  = 8 * 1024
+	buf16K = 16 * 1024
+	buf32K = 32 * 1024
+)
+
+// NewTarSum creates a new interface for calculating a fixed time checksum of a
+// tar archive.
+//
+// This is used for calculating checksums of layers of an image, in some cases
+// including the byte payload of the image's json metadata as well, and for
+// calculating the checksums for buildcache.
+func NewTarSum(r io.Reader, dc bool, v Version) (TarSum, error) {
+	return NewTarSumHash(r, dc, v, DefaultTHash)
+}
+
+// NewTarSumHash creates a new TarSum, providing a THash to use rather than
+// the DefaultTHash.
+func NewTarSumHash(r io.Reader, dc bool, v Version, tHash THash) (TarSum, error) {
+	headerSelector, err := getTarHeaderSelector(v)
+	if err != nil {
+		return nil, err
+	}
+	ts := &tarSum{Reader: r, DisableCompression: dc, tarSumVersion: v, headerSelector: headerSelector, tHash: tHash}
+	err = ts.initTarSum()
+	return ts, err
+}
+
+// NewTarSumForLabel creates a new TarSum using the provided TarSum version+hash label.
+func NewTarSumForLabel(r io.Reader, disableCompression bool, label string) (TarSum, error) {
+	parts := strings.SplitN(label, "+", 2)
+	if len(parts) != 2 {
+		return nil, errors.New("tarsum label string should be of the form: {tarsum_version}+{hash_name}")
+	}
+
+	versionName, hashName := parts[0], parts[1]
+
+	version, ok := tarSumVersionsByName[versionName]
+	if !ok {
+		return nil, fmt.Errorf("unknown TarSum version name: %q", versionName)
+	}
+
+	hashConfig, ok := standardHashConfigs[hashName]
+	if !ok {
+		return nil, fmt.Errorf("unknown TarSum hash name: %q", hashName)
+	}
+
+	tHash := NewTHash(hashConfig.name, hashConfig.hash.New)
+
+	return NewTarSumHash(r, disableCompression, version, tHash)
+}
+
+// TarSum is the generic interface for calculating fixed time
+// checksums of a tar archive.
+type TarSum interface {
+	io.Reader
+	GetSums() FileInfoSums
+	Sum([]byte) string
+	Version() Version
+	Hash() THash
+}
+
+// tarSum struct is the structure for a Version0 checksum calculation.
+type tarSum struct {
+	io.Reader
+	tarR               *tar.Reader
+	tarW               *tar.Writer
+	writer             writeCloseFlusher
+	bufTar             *bytes.Buffer
+	bufWriter          *bytes.Buffer
+	bufData            []byte
+	h                  hash.Hash
+	tHash              THash
+	sums               FileInfoSums
+	fileCounter        int64
+	currentFile        string
+	finished           bool
+	first              bool
+	DisableCompression bool              // false by default. When false, the output gzip compressed.
+	tarSumVersion      Version           // this field is not exported so it can not be mutated during use
+	headerSelector     tarHeaderSelector // handles selecting and ordering headers for files in the archive
+}
+
+func (ts tarSum) Hash() THash {
+	return ts.tHash
+}
+
+func (ts tarSum) Version() Version {
+	return ts.tarSumVersion
+}
+
+// THash provides a hash.Hash type generator and its name.
+type THash interface {
+	Hash() hash.Hash
+	Name() string
+}
+
+// NewTHash is a convenience method for creating a THash.
+func NewTHash(name string, h func() hash.Hash) THash {
+	return simpleTHash{n: name, h: h}
+}
+
+type tHashConfig struct {
+	name string
+	hash crypto.Hash
+}
+
+var (
+	// NOTE: DO NOT include MD5 or SHA1, which are considered insecure.
+	standardHashConfigs = map[string]tHashConfig{
+		"sha256": {name: "sha256", hash: crypto.SHA256},
+		"sha512": {name: "sha512", hash: crypto.SHA512},
+	}
+)
+
+// DefaultTHash is default TarSum hashing algorithm - "sha256".
+var DefaultTHash = NewTHash("sha256", sha256.New)
+
+type simpleTHash struct {
+	n string
+	h func() hash.Hash
+}
+
+func (sth simpleTHash) Name() string    { return sth.n }
+func (sth simpleTHash) Hash() hash.Hash { return sth.h() }
+
+func (ts *tarSum) encodeHeader(h *tar.Header) error {
+	for _, elem := range ts.headerSelector.selectHeaders(h) {
+		if _, err := ts.h.Write([]byte(elem[0] + elem[1])); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (ts *tarSum) initTarSum() error {
+	ts.bufTar = bytes.NewBuffer([]byte{})
+	ts.bufWriter = bytes.NewBuffer([]byte{})
+	ts.tarR = tar.NewReader(ts.Reader)
+	ts.tarW = tar.NewWriter(ts.bufTar)
+	if !ts.DisableCompression {
+		ts.writer = gzip.NewWriter(ts.bufWriter)
+	} else {
+		ts.writer = &nopCloseFlusher{Writer: ts.bufWriter}
+	}
+	if ts.tHash == nil {
+		ts.tHash = DefaultTHash
+	}
+	ts.h = ts.tHash.Hash()
+	ts.h.Reset()
+	ts.first = true
+	ts.sums = FileInfoSums{}
+	return nil
+}
+
+func (ts *tarSum) Read(buf []byte) (int, error) {
+	if ts.finished {
+		return ts.bufWriter.Read(buf)
+	}
+	if len(ts.bufData) < len(buf) {
+		switch {
+		case len(buf) <= buf8K:
+			ts.bufData = make([]byte, buf8K)
+		case len(buf) <= buf16K:
+			ts.bufData = make([]byte, buf16K)
+		case len(buf) <= buf32K:
+			ts.bufData = make([]byte, buf32K)
+		default:
+			ts.bufData = make([]byte, len(buf))
+		}
+	}
+	buf2 := ts.bufData[:len(buf)]
+
+	n, err := ts.tarR.Read(buf2)
+	if err != nil {
+		if err == io.EOF {
+			if _, err := ts.h.Write(buf2[:n]); err != nil {
+				return 0, err
+			}
+			if !ts.first {
+				ts.sums = append(ts.sums, fileInfoSum{name: ts.currentFile, sum: hex.EncodeToString(ts.h.Sum(nil)), pos: ts.fileCounter})
+				ts.fileCounter++
+				ts.h.Reset()
+			} else {
+				ts.first = false
+			}
+
+			currentHeader, err := ts.tarR.Next()
+			if err != nil {
+				if err == io.EOF {
+					if err := ts.tarW.Close(); err != nil {
+						return 0, err
+					}
+					if _, err := io.Copy(ts.writer, ts.bufTar); err != nil {
+						return 0, err
+					}
+					if err := ts.writer.Close(); err != nil {
+						return 0, err
+					}
+					ts.finished = true
+					return n, nil
+				}
+				return n, err
+			}
+			ts.currentFile = path.Clean(currentHeader.Name)
+			if err := ts.encodeHeader(currentHeader); err != nil {
+				return 0, err
+			}
+			if err := ts.tarW.WriteHeader(currentHeader); err != nil {
+				return 0, err
+			}
+			if _, err := ts.tarW.Write(buf2[:n]); err != nil {
+				return 0, err
+			}
+			ts.tarW.Flush()
+			if _, err := io.Copy(ts.writer, ts.bufTar); err != nil {
+				return 0, err
+			}
+			ts.writer.Flush()
+
+			return ts.bufWriter.Read(buf)
+		}
+		return n, err
+	}
+
+	// Filling the hash buffer
+	if _, err = ts.h.Write(buf2[:n]); err != nil {
+		return 0, err
+	}
+
+	// Filling the tar writer
+	if _, err = ts.tarW.Write(buf2[:n]); err != nil {
+		return 0, err
+	}
+	ts.tarW.Flush()
+
+	// Filling the output writer
+	if _, err = io.Copy(ts.writer, ts.bufTar); err != nil {
+		return 0, err
+	}
+	ts.writer.Flush()
+
+	return ts.bufWriter.Read(buf)
+}
+
+func (ts *tarSum) Sum(extra []byte) string {
+	ts.sums.SortBySums()
+	h := ts.tHash.Hash()
+	if extra != nil {
+		h.Write(extra)
+	}
+	for _, fis := range ts.sums {
+		h.Write([]byte(fis.Sum()))
+	}
+	checksum := ts.Version().String() + "+" + ts.tHash.Name() + ":" + hex.EncodeToString(h.Sum(nil))
+	return checksum
+}
+
+func (ts *tarSum) GetSums() FileInfoSums {
+	return ts.sums
+}

vendor/github.com/docker/docker/pkg/tarsum/versioning.go

@@ -0,0 +1,158 @@
+package tarsum
+
+import (
+	"archive/tar"
+	"errors"
+	"io"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Version is used for versioning of the TarSum algorithm
+// based on the prefix of the hash used
+// i.e. "tarsum+sha256:e58fcf7418d4390dec8e8fb69d88c06ec07039d651fedd3aa72af9972e7d046b"
+type Version int
+
+// Prefix of "tarsum"
+const (
+	Version0 Version = iota
+	Version1
+	// VersionDev this constant will be either the latest or an unsettled next-version of the TarSum calculation
+	VersionDev
+)
+
+// WriteV1Header writes a tar header to a writer in V1 tarsum format.
+func WriteV1Header(h *tar.Header, w io.Writer) {
+	for _, elem := range v1TarHeaderSelect(h) {
+		w.Write([]byte(elem[0] + elem[1]))
+	}
+}
+
+// VersionLabelForChecksum returns the label for the given tarsum
+// checksum, i.e., everything before the first `+` character in
+// the string or an empty string if no label separator is found.
+func VersionLabelForChecksum(checksum string) string {
+	// Checksums are in the form: {versionLabel}+{hashID}:{hex}
+	sepIndex := strings.Index(checksum, "+")
+	if sepIndex < 0 {
+		return ""
+	}
+	return checksum[:sepIndex]
+}
+
+// GetVersions gets a list of all known tarsum versions.
+func GetVersions() []Version {
+	v := []Version{}
+	for k := range tarSumVersions {
+		v = append(v, k)
+	}
+	return v
+}
+
+var (
+	tarSumVersions = map[Version]string{
+		Version0:   "tarsum",
+		Version1:   "tarsum.v1",
+		VersionDev: "tarsum.dev",
+	}
+	tarSumVersionsByName = map[string]Version{
+		"tarsum":     Version0,
+		"tarsum.v1":  Version1,
+		"tarsum.dev": VersionDev,
+	}
+)
+
+func (tsv Version) String() string {
+	return tarSumVersions[tsv]
+}
+
+// GetVersionFromTarsum returns the Version from the provided string.
+func GetVersionFromTarsum(tarsum string) (Version, error) {
+	tsv := tarsum
+	if strings.Contains(tarsum, "+") {
+		tsv = strings.SplitN(tarsum, "+", 2)[0]
+	}
+	for v, s := range tarSumVersions {
+		if s == tsv {
+			return v, nil
+		}
+	}
+	return -1, ErrNotVersion
+}
+
+// Errors that may be returned by functions in this package
+var (
+	ErrNotVersion            = errors.New("string does not include a TarSum Version")
+	ErrVersionNotImplemented = errors.New("TarSum Version is not yet implemented")
+)
+
+// tarHeaderSelector is the interface which different versions
+// of tarsum should use for selecting and ordering tar headers
+// for each item in the archive.
+type tarHeaderSelector interface {
+	selectHeaders(h *tar.Header) (orderedHeaders [][2]string)
+}
+
+type tarHeaderSelectFunc func(h *tar.Header) (orderedHeaders [][2]string)
+
+func (f tarHeaderSelectFunc) selectHeaders(h *tar.Header) (orderedHeaders [][2]string) {
+	return f(h)
+}
+
+func v0TarHeaderSelect(h *tar.Header) (orderedHeaders [][2]string) {
+	return [][2]string{
+		{"name", h.Name},
+		{"mode", strconv.FormatInt(h.Mode, 10)},
+		{"uid", strconv.Itoa(h.Uid)},
+		{"gid", strconv.Itoa(h.Gid)},
+		{"size", strconv.FormatInt(h.Size, 10)},
+		{"mtime", strconv.FormatInt(h.ModTime.UTC().Unix(), 10)},
+		{"typeflag", string([]byte{h.Typeflag})},
+		{"linkname", h.Linkname},
+		{"uname", h.Uname},
+		{"gname", h.Gname},
+		{"devmajor", strconv.FormatInt(h.Devmajor, 10)},
+		{"devminor", strconv.FormatInt(h.Devminor, 10)},
+	}
+}
+
+func v1TarHeaderSelect(h *tar.Header) (orderedHeaders [][2]string) {
+	// Get extended attributes.
+	xAttrKeys := make([]string, len(h.Xattrs))
+	for k := range h.Xattrs {
+		xAttrKeys = append(xAttrKeys, k)
+	}
+	sort.Strings(xAttrKeys)
+
+	// Make the slice with enough capacity to hold the 11 basic headers
+	// we want from the v0 selector plus however many xattrs we have.
+	orderedHeaders = make([][2]string, 0, 11+len(xAttrKeys))
+
+	// Copy all headers from v0 excluding the 'mtime' header (the 5th element).
+	v0headers := v0TarHeaderSelect(h)
+	orderedHeaders = append(orderedHeaders, v0headers[0:5]...)
+	orderedHeaders = append(orderedHeaders, v0headers[6:]...)
+
+	// Finally, append the sorted xattrs.
+	for _, k := range xAttrKeys {
+		orderedHeaders = append(orderedHeaders, [2]string{k, h.Xattrs[k]})
+	}
+
+	return
+}
+
+var registeredHeaderSelectors = map[Version]tarHeaderSelectFunc{
+	Version0:   v0TarHeaderSelect,
+	Version1:   v1TarHeaderSelect,
+	VersionDev: v1TarHeaderSelect,
+}
+
+func getTarHeaderSelector(v Version) (tarHeaderSelector, error) {
+	headerSelector, ok := registeredHeaderSelectors[v]
+	if !ok {
+		return nil, ErrVersionNotImplemented
+	}
+
+	return headerSelector, nil
+}

vendor/github.com/docker/docker/pkg/tarsum/writercloser.go

@@ -0,0 +1,22 @@
+package tarsum
+
+import (
+	"io"
+)
+
+type writeCloseFlusher interface {
+	io.WriteCloser
+	Flush() error
+}
+
+type nopCloseFlusher struct {
+	io.Writer
+}
+
+func (n *nopCloseFlusher) Close() error {
+	return nil
+}
+
+func (n *nopCloseFlusher) Flush() error {
+	return nil
+}

vendor/github.com/opencontainers/runc/libcontainer/user/lookup.go

@@ -0,0 +1,111 @@
+package user
+
+import (
+	"errors"
+
+	"golang.org/x/sys/unix"
+)
+
+var (
+	// The current operating system does not provide the required data for user lookups.
+	ErrUnsupported = errors.New("user lookup: operating system does not provide passwd-formatted data")
+	// No matching entries found in file.
+	ErrNoPasswdEntries = errors.New("no matching entries in passwd file")
+	ErrNoGroupEntries  = errors.New("no matching entries in group file")
+)
+
+func lookupUser(filter func(u User) bool) (User, error) {
+	// Get operating system-specific passwd reader-closer.
+	passwd, err := GetPasswd()
+	if err != nil {
+		return User{}, err
+	}
+	defer passwd.Close()
+
+	// Get the users.
+	users, err := ParsePasswdFilter(passwd, filter)
+	if err != nil {
+		return User{}, err
+	}
+
+	// No user entries found.
+	if len(users) == 0 {
+		return User{}, ErrNoPasswdEntries
+	}
+
+	// Assume the first entry is the "correct" one.
+	return users[0], nil
+}
+
+// CurrentUser looks up the current user by their user id in /etc/passwd. If the
+// user cannot be found (or there is no /etc/passwd file on the filesystem),
+// then CurrentUser returns an error.
+func CurrentUser() (User, error) {
+	return LookupUid(unix.Getuid())
+}
+
+// LookupUser looks up a user by their username in /etc/passwd. If the user
+// cannot be found (or there is no /etc/passwd file on the filesystem), then
+// LookupUser returns an error.
+func LookupUser(username string) (User, error) {
+	return lookupUser(func(u User) bool {
+		return u.Name == username
+	})
+}
+
+// LookupUid looks up a user by their user id in /etc/passwd. If the user cannot
+// be found (or there is no /etc/passwd file on the filesystem), then LookupId
+// returns an error.
+func LookupUid(uid int) (User, error) {
+	return lookupUser(func(u User) bool {
+		return u.Uid == uid
+	})
+}
+
+func lookupGroup(filter func(g Group) bool) (Group, error) {
+	// Get operating system-specific group reader-closer.
+	group, err := GetGroup()
+	if err != nil {
+		return Group{}, err
+	}
+	defer group.Close()
+
+	// Get the users.
+	groups, err := ParseGroupFilter(group, filter)
+	if err != nil {
+		return Group{}, err
+	}
+
+	// No user entries found.
+	if len(groups) == 0 {
+		return Group{}, ErrNoGroupEntries
+	}
+
+	// Assume the first entry is the "correct" one.
+	return groups[0], nil
+}
+
+// CurrentGroup looks up the current user's group by their primary group id's
+// entry in /etc/passwd. If the group cannot be found (or there is no
+// /etc/group file on the filesystem), then CurrentGroup returns an error.
+func CurrentGroup() (Group, error) {
+	return LookupGid(unix.Getgid())
+}
+
+// LookupGroup looks up a group by its name in /etc/group. If the group cannot
+// be found (or there is no /etc/group file on the filesystem), then LookupGroup
+// returns an error.
+func LookupGroup(groupname string) (Group, error) {
+	return lookupGroup(func(g Group) bool {
+		return g.Name == groupname
+	})
+}
+
+// LookupGid looks up a group by its group id in /etc/group. If the group cannot
+// be found (or there is no /etc/group file on the filesystem), then LookupGid
+// returns an error.
+func LookupGid(gid int) (Group, error) {
+	return lookupGroup(func(g Group) bool {
+		return g.Gid == gid
+	})
+}

vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unix.go

@@ -0,0 +1,30 @@
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package user
+
+import (
+	"io"
+	"os"
+)
+
+// Unix-specific path to the passwd and group formatted files.
+const (
+	unixPasswdPath = "/etc/passwd"
+	unixGroupPath  = "/etc/group"
+)
+
+func GetPasswdPath() (string, error) {
+	return unixPasswdPath, nil
+}
+
+func GetPasswd() (io.ReadCloser, error) {
+	return os.Open(unixPasswdPath)
+}
+
+func GetGroupPath() (string, error) {
+	return unixGroupPath, nil
+}
+
+func GetGroup() (io.ReadCloser, error) {
+	return os.Open(unixGroupPath)
+}

vendor/github.com/opencontainers/runc/libcontainer/user/lookup_unsupported.go

@@ -0,0 +1,21 @@
+// +build !darwin,!dragonfly,!freebsd,!linux,!netbsd,!openbsd,!solaris
+
+package user
+
+import "io"
+
+func GetPasswdPath() (string, error) {
+	return "", ErrUnsupported
+}
+
+func GetPasswd() (io.ReadCloser, error) {
+	return nil, ErrUnsupported
+}
+
+func GetGroupPath() (string, error) {
+	return "", ErrUnsupported
+}
+
+func GetGroup() (io.ReadCloser, error) {
+	return nil, ErrUnsupported
+}

vendor/github.com/opencontainers/runc/libcontainer/user/user.go

@@ -0,0 +1,441 @@
+package user
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	minId = 0
+	maxId = 1<<31 - 1 //for 32-bit systems compatibility
+)
+
+var (
+	ErrRange = fmt.Errorf("uids and gids must be in range %d-%d", minId, maxId)
+)
+
+type User struct {
+	Name  string
+	Pass  string
+	Uid   int
+	Gid   int
+	Gecos string
+	Home  string
+	Shell string
+}
+
+type Group struct {
+	Name string
+	Pass string
+	Gid  int
+	List []string
+}
+
+func parseLine(line string, v ...interface{}) {
+	if line == "" {
+		return
+	}
+
+	parts := strings.Split(line, ":")
+	for i, p := range parts {
+		// Ignore cases where we don't have enough fields to populate the arguments.
+		// Some configuration files like to misbehave.
+		if len(v) <= i {
+			break
+		}
+
+		// Use the type of the argument to figure out how to parse it, scanf() style.
+		// This is legit.
+		switch e := v[i].(type) {
+		case *string:
+			*e = p
+		case *int:
+			// "numbers", with conversion errors ignored because of some misbehaving configuration files.
+			*e, _ = strconv.Atoi(p)
+		case *[]string:
+			// Comma-separated lists.
+			if p != "" {
+				*e = strings.Split(p, ",")
+			} else {
+				*e = []string{}
+			}
+		default:
+			// Someone goof'd when writing code using this function. Scream so they can hear us.
+			panic(fmt.Sprintf("parseLine only accepts {*string, *int, *[]string} as arguments! %#v is not a pointer!", e))
+		}
+	}
+}
+
+func ParsePasswdFile(path string) ([]User, error) {
+	passwd, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer passwd.Close()
+	return ParsePasswd(passwd)
+}
+
+func ParsePasswd(passwd io.Reader) ([]User, error) {
+	return ParsePasswdFilter(passwd, nil)
+}
+
+func ParsePasswdFileFilter(path string, filter func(User) bool) ([]User, error) {
+	passwd, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer passwd.Close()
+	return ParsePasswdFilter(passwd, filter)
+}
+
+func ParsePasswdFilter(r io.Reader, filter func(User) bool) ([]User, error) {
+	if r == nil {
+		return nil, fmt.Errorf("nil source for passwd-formatted data")
+	}
+
+	var (
+		s   = bufio.NewScanner(r)
+		out = []User{}
+	)
+
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+
+		line := strings.TrimSpace(s.Text())
+		if line == "" {
+			continue
+		}
+
+		// see: man 5 passwd
+		//  name:password:UID:GID:GECOS:directory:shell
+		// Name:Pass:Uid:Gid:Gecos:Home:Shell
+		//  root:x:0:0:root:/root:/bin/bash
+		//  adm:x:3:4:adm:/var/adm:/bin/false
+		p := User{}
+		parseLine(line, &p.Name, &p.Pass, &p.Uid, &p.Gid, &p.Gecos, &p.Home, &p.Shell)
+
+		if filter == nil || filter(p) {
+			out = append(out, p)
+		}
+	}
+
+	return out, nil
+}
+
+func ParseGroupFile(path string) ([]Group, error) {
+	group, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	defer group.Close()
+	return ParseGroup(group)
+}
+
+func ParseGroup(group io.Reader) ([]Group, error) {
+	return ParseGroupFilter(group, nil)
+}
+
+func ParseGroupFileFilter(path string, filter func(Group) bool) ([]Group, error) {
+	group, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer group.Close()
+	return ParseGroupFilter(group, filter)
+}
+
+func ParseGroupFilter(r io.Reader, filter func(Group) bool) ([]Group, error) {
+	if r == nil {
+		return nil, fmt.Errorf("nil source for group-formatted data")
+	}
+
+	var (
+		s   = bufio.NewScanner(r)
+		out = []Group{}
+	)
+
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+
+		text := s.Text()
+		if text == "" {
+			continue
+		}
+
+		// see: man 5 group
+		//  group_name:password:GID:user_list
+		// Name:Pass:Gid:List
+		//  root:x:0:root
+		//  adm:x:4:root,adm,daemon
+		p := Group{}
+		parseLine(text, &p.Name, &p.Pass, &p.Gid, &p.List)
+
+		if filter == nil || filter(p) {
+			out = append(out, p)
+		}
+	}
+
+	return out, nil
+}
+
+type ExecUser struct {
+	Uid   int
+	Gid   int
+	Sgids []int
+	Home  string
+}
+
+// GetExecUserPath is a wrapper for GetExecUser. It reads data from each of the
+// given file paths and uses that data as the arguments to GetExecUser. If the
+// files cannot be opened for any reason, the error is ignored and a nil
+// io.Reader is passed instead.
+func GetExecUserPath(userSpec string, defaults *ExecUser, passwdPath, groupPath string) (*ExecUser, error) {
+	var passwd, group io.Reader
+
+	if passwdFile, err := os.Open(passwdPath); err == nil {
+		passwd = passwdFile
+		defer passwdFile.Close()
+	}
+
+	if groupFile, err := os.Open(groupPath); err == nil {
+		group = groupFile
+		defer groupFile.Close()
+	}
+
+	return GetExecUser(userSpec, defaults, passwd, group)
+}
+
+// GetExecUser parses a user specification string (using the passwd and group
+// readers as sources for /etc/passwd and /etc/group data, respectively). In
+// the case of blank fields or missing data from the sources, the values in
+// defaults is used.
+//
+// GetExecUser will return an error if a user or group literal could not be
+// found in any entry in passwd and group respectively.
+//
+// Examples of valid user specifications are:
+//     * ""
+//     * "user"
+//     * "uid"
+//     * "user:group"
+//     * "uid:gid
+//     * "user:gid"
+//     * "uid:group"
+//
+// It should be noted that if you specify a numeric user or group id, they will
+// not be evaluated as usernames (only the metadata will be filled). So attempting
+// to parse a user with user.Name = "1337" will produce the user with a UID of
+// 1337.
+func GetExecUser(userSpec string, defaults *ExecUser, passwd, group io.Reader) (*ExecUser, error) {
+	if defaults == nil {
+		defaults = new(ExecUser)
+	}
+
+	// Copy over defaults.
+	user := &ExecUser{
+		Uid:   defaults.Uid,
+		Gid:   defaults.Gid,
+		Sgids: defaults.Sgids,
+		Home:  defaults.Home,
+	}
+
+	// Sgids slice *cannot* be nil.
+	if user.Sgids == nil {
+		user.Sgids = []int{}
+	}
+
+	// Allow for userArg to have either "user" syntax, or optionally "user:group" syntax
+	var userArg, groupArg string
+	parseLine(userSpec, &userArg, &groupArg)
+
+	// Convert userArg and groupArg to be numeric, so we don't have to execute
+	// Atoi *twice* for each iteration over lines.
+	uidArg, uidErr := strconv.Atoi(userArg)
+	gidArg, gidErr := strconv.Atoi(groupArg)
+
+	// Find the matching user.
+	users, err := ParsePasswdFilter(passwd, func(u User) bool {
+		if userArg == "" {
+			// Default to current state of the user.
+			return u.Uid == user.Uid
+		}
+
+		if uidErr == nil {
+			// If the userArg is numeric, always treat it as a UID.
+			return uidArg == u.Uid
+		}
+
+		return u.Name == userArg
+	})
+
+	// If we can't find the user, we have to bail.
+	if err != nil && passwd != nil {
+		if userArg == "" {
+			userArg = strconv.Itoa(user.Uid)
+		}
+		return nil, fmt.Errorf("unable to find user %s: %v", userArg, err)
+	}
+
+	var matchedUserName string
+	if len(users) > 0 {
+		// First match wins, even if there's more than one matching entry.
+		matchedUserName = users[0].Name
+		user.Uid = users[0].Uid
+		user.Gid = users[0].Gid
+		user.Home = users[0].Home
+	} else if userArg != "" {
+		// If we can't find a user with the given username, the only other valid
+		// option is if it's a numeric username with no associated entry in passwd.
+
+		if uidErr != nil {
+			// Not numeric.
+			return nil, fmt.Errorf("unable to find user %s: %v", userArg, ErrNoPasswdEntries)
+		}
+		user.Uid = uidArg
+
+		// Must be inside valid uid range.
+		if user.Uid < minId || user.Uid > maxId {
+			return nil, ErrRange
+		}
+
+		// Okay, so it's numeric. We can just roll with this.
+	}
+
+	// On to the groups. If we matched a username, we need to do this because of
+	// the supplementary group IDs.
+	if groupArg != "" || matchedUserName != "" {
+		groups, err := ParseGroupFilter(group, func(g Group) bool {
+			// If the group argument isn't explicit, we'll just search for it.
+			if groupArg == "" {
+				// Check if user is a member of this group.
+				for _, u := range g.List {
+					if u == matchedUserName {
+						return true
+					}
+				}
+				return false
+			}
+
+			if gidErr == nil {
+				// If the groupArg is numeric, always treat it as a GID.
+				return gidArg == g.Gid
+			}
+
+			return g.Name == groupArg
+		})
+		if err != nil && group != nil {
+			return nil, fmt.Errorf("unable to find groups for spec %v: %v", matchedUserName, err)
+		}
+
+		// Only start modifying user.Gid if it is in explicit form.
+		if groupArg != "" {
+			if len(groups) > 0 {
+				// First match wins, even if there's more than one matching entry.
+				user.Gid = groups[0].Gid
+			} else {
+				// If we can't find a group with the given name, the only other valid
+				// option is if it's a numeric group name with no associated entry in group.
+
+				if gidErr != nil {
+					// Not numeric.
+					return nil, fmt.Errorf("unable to find group %s: %v", groupArg, ErrNoGroupEntries)
+				}
+				user.Gid = gidArg
+
+				// Must be inside valid gid range.
+				if user.Gid < minId || user.Gid > maxId {
+					return nil, ErrRange
+				}
+
+				// Okay, so it's numeric. We can just roll with this.
+			}
+		} else if len(groups) > 0 {
+			// Supplementary group ids only make sense if in the implicit form.
+			user.Sgids = make([]int, len(groups))
+			for i, group := range groups {
+				user.Sgids[i] = group.Gid
+			}
+		}
+	}
+
+	return user, nil
+}
+
+// GetAdditionalGroups looks up a list of groups by name or group id
+// against the given /etc/group formatted data. If a group name cannot
+// be found, an error will be returned. If a group id cannot be found,
+// or the given group data is nil, the id will be returned as-is
+// provided it is in the legal range.
+func GetAdditionalGroups(additionalGroups []string, group io.Reader) ([]int, error) {
+	var groups = []Group{}
+	if group != nil {
+		var err error
+		groups, err = ParseGroupFilter(group, func(g Group) bool {
+			for _, ag := range additionalGroups {
+				if g.Name == ag || strconv.Itoa(g.Gid) == ag {
+					return true
+				}
+			}
+			return false
+		})
+		if err != nil {
+			return nil, fmt.Errorf("Unable to find additional groups %v: %v", additionalGroups, err)
+		}
+	}
+
+	gidMap := make(map[int]struct{})
+	for _, ag := range additionalGroups {
+		var found bool
+		for _, g := range groups {
+			// if we found a matched group either by name or gid, take the
+			// first matched as correct
+			if g.Name == ag || strconv.Itoa(g.Gid) == ag {
+				if _, ok := gidMap[g.Gid]; !ok {
+					gidMap[g.Gid] = struct{}{}
+					found = true
+					break
+				}
+			}
+		}
+		// we asked for a group but didn't find it. let's check to see
+		// if we wanted a numeric group
+		if !found {
+			gid, err := strconv.Atoi(ag)
+			if err != nil {
+				return nil, fmt.Errorf("Unable to find group %s", ag)
+			}
+			// Ensure gid is inside gid range.
+			if gid < minId || gid > maxId {
+				return nil, ErrRange
+			}
+			gidMap[gid] = struct{}{}
+		}
+	}
+	gids := []int{}
+	for gid := range gidMap {
+		gids = append(gids, gid)
+	}
+	return gids, nil
+}
+
+// GetAdditionalGroupsPath is a wrapper around GetAdditionalGroups
+// that opens the groupPath given and gives it as an argument to
+// GetAdditionalGroups.
+func GetAdditionalGroupsPath(additionalGroups []string, groupPath string) ([]int, error) {
+	var group io.Reader
+
+	if groupFile, err := os.Open(groupPath); err == nil {
+		group = groupFile
+		defer groupFile.Close()
+	}
+	return GetAdditionalGroups(additionalGroups, group)
+}

vendor/github.com/stevvooe/continuity/LICENSE

@@ -0,0 +1,202 @@
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vendor/github.com/stevvooe/continuity/README.md

@@ -0,0 +1,19 @@
+# continuity
+
+[![GoDoc](https://godoc.org/github.com/containerd/continuity?status.svg)](https://godoc.org/github.com/containerd/continuity)
+[![Build Status](https://travis-ci.org/containerd/continuity.svg?branch=master)](https://travis-ci.org/containerd/continuity)
+
+A transport-agnostic, filesystem metadata manifest system
+
+This project is a staging area for experiments in providing transport agnostic
+metadata storage.
+
+Please see https://github.com/opencontainers/specs/issues/11 for more details.
+
+## Building Proto Package
+
+If you change the proto file you will need to rebuild the generated Go with `go generate`.
+
+```
+go generate ./proto
+```