Add basic import and export handlers

Signed-off-by: Derek McGowan <derek@mcg.dev>

pkg/transfer/archive/exporter.go

@@ -0,0 +1,87 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package archive
+
+import (
+	"context"
+	"io"
+
+	transferapi "github.com/containerd/containerd/api/types/transfer"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/pkg/streaming"
+	tstreaming "github.com/containerd/containerd/pkg/transfer/streaming"
+	"github.com/containerd/typeurl"
+)
+
+// NewImageImportStream returns a image importer via tar stream
+// TODO: Add import options
+func NewImageExportStream(stream io.WriteCloser) *ImageExportStream {
+	return &ImageExportStream{
+		stream: stream,
+	}
+}
+
+type ImageExportStream struct {
+	stream io.WriteCloser
+}
+
+func (iis *ImageExportStream) ExportStream(context.Context) (io.WriteCloser, error) {
+	return iis.stream, nil
+}
+
+func (iis *ImageExportStream) MarshalAny(ctx context.Context, sm streaming.StreamManager) (typeurl.Any, error) {
+	// TODO: Unique stream ID
+	sid := "randomid"
+	// TODO: Should this API be create instead of get
+	stream, err := sm.Get(ctx, sid)
+	if err != nil {
+		return nil, err
+	}
+
+	// Receive stream and copy to writer
+	go func() {
+		if _, err := io.Copy(iis.stream, tstreaming.ReceiveStream(ctx, stream)); err != nil {
+			log.G(ctx).WithError(err).WithField("streamid", sid).Errorf("error copying stream")
+		}
+		iis.stream.Close()
+	}()
+
+	s := &transferapi.ImageExportStream{
+		Stream: sid,
+	}
+
+	return typeurl.MarshalAny(s)
+}
+
+func (iis *ImageExportStream) UnmarshalAny(ctx context.Context, sm streaming.StreamManager, any typeurl.Any) error {
+	var s transferapi.ImageExportStream
+	if err := typeurl.UnmarshalTo(any, &s); err != nil {
+		return err
+	}
+
+	stream, err := sm.Get(ctx, s.Stream)
+	if err != nil {
+		return err
+	}
+
+	r, w := io.Pipe()
+
+	tstreaming.SendStream(ctx, r, stream)
+	iis.stream = w
+
+	return nil
+}

pkg/transfer/archive/importer.go

@@ -0,0 +1,76 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package archive
+
+import (
+	"context"
+	"io"
+
+	transferapi "github.com/containerd/containerd/api/types/transfer"
+	"github.com/containerd/containerd/pkg/streaming"
+	tstreaming "github.com/containerd/containerd/pkg/transfer/streaming"
+	"github.com/containerd/typeurl"
+)
+
+// NewImageImportStream returns a image importer via tar stream
+// TODO: Add import options
+func NewImageImportStream(stream io.Reader) *ImageImportStream {
+	return &ImageImportStream{
+		stream: stream,
+	}
+}
+
+type ImageImportStream struct {
+	stream io.Reader
+}
+
+func (iis *ImageImportStream) ImportStream(context.Context) (io.Reader, error) {
+	return iis.stream, nil
+}
+
+func (iis *ImageImportStream) MarshalAny(ctx context.Context, sm streaming.StreamManager) (typeurl.Any, error) {
+	// TODO: Unique stream ID
+	sid := "randomid"
+	// TODO: Should this API be create instead of get
+	stream, err := sm.Get(ctx, sid)
+	if err != nil {
+		return nil, err
+	}
+	tstreaming.SendStream(ctx, iis.stream, stream)
+
+	s := &transferapi.ImageImportStream{
+		Stream: sid,
+	}
+
+	return typeurl.MarshalAny(s)
+}
+
+func (iis *ImageImportStream) UnmarshalAny(ctx context.Context, sm streaming.StreamManager, any typeurl.Any) error {
+	var s transferapi.ImageImportStream
+	if err := typeurl.UnmarshalTo(any, &s); err != nil {
+		return err
+	}
+
+	stream, err := sm.Get(ctx, s.Stream)
+	if err != nil {
+		return err
+	}
+
+	iis.stream = tstreaming.ReceiveStream(ctx, stream)
+
+	return nil
+}

pkg/transfer/transfer.go

@@ -50,6 +50,17 @@ type ImageStorer interface {
 	Store(context.Context, ocispec.Descriptor) (images.Image, error)
 }
 
+// ImageImportStreamer returns an import streamer based on OCI or
+// Docker image tar archives. The stream should be a raw tar stream
+// and without compression.
+type ImageImportStreamer interface {
+	ImportStream(context.Context) (io.Reader, error)
+}
+
+type ImageExportStreamer interface {
+	ExportStream(context.Context) (io.WriteCloser, error)
+}
+
 type ImageUnpacker interface {
 	// TODO: Or unpack options?
 	UnpackPlatforms() []unpack.Platform