add image load/save support

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

api/server/router/image/backend.go

@@ -30,9 +30,9 @@ type imageBackend interface {
 }
 
 type importExportBackend interface {
-	LoadImage(inTar io.ReadCloser, outStream io.Writer, quiet bool) error
+	LoadImage(ctx context.Context, inTar io.ReadCloser, outStream io.Writer, quiet bool) error
 	ImportImage(src string, repository string, platform *specs.Platform, tag string, msg string, inConfig io.ReadCloser, outStream io.Writer, changes []string) error
-	ExportImage(names []string, outStream io.Writer) error
+	ExportImage(ctx context.Context, names []string, outStream io.Writer) error
 }
 
 type registryBackend interface {

api/server/router/image/image_routes.go

@@ -137,7 +137,7 @@ func (s *imageRouter) getImagesGet(ctx context.Context, w http.ResponseWriter, r
 		names = r.Form["names"]
 	}
 
-	if err := s.backend.ExportImage(names, output); err != nil {
+	if err := s.backend.ExportImage(ctx, names, output); err != nil {
 		if !output.Flushed() {
 			return err
 		}
@@ -156,7 +156,7 @@ func (s *imageRouter) postImagesLoad(ctx context.Context, w http.ResponseWriter,
 
 	output := ioutils.NewWriteFlusher(w)
 	defer output.Close()
-	if err := s.backend.LoadImage(r.Body, output, quiet); err != nil {
+	if err := s.backend.LoadImage(ctx, r.Body, output, quiet); err != nil {
 		_, _ = output.Write(streamformatter.FormatError(err))
 	}
 	return nil

daemon/containerd/image_exporter.go

@@ -1,19 +1,42 @@
 package containerd
 
-import "io"
+import (
+	"context"
+	"io"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/images/archive"
+	"github.com/containerd/containerd/platforms"
+	"github.com/docker/distribution/reference"
+)
 
 // ExportImage exports a list of images to the given output stream. The
 // exported images are archived into a tar when written to the output
 // stream. All images with the given tag and all versions containing
 // the same tag are exported. names is the set of tags to export, and
 // outStream is the writer which the images are written to.
-func (i *ImageService) ExportImage(names []string, outStream io.Writer) error {
-	panic("not implemented")
+func (i *ImageService) ExportImage(ctx context.Context, names []string, outStream io.Writer) error {
+	opts := []archive.ExportOpt{
+		archive.WithPlatform(platforms.Ordered(platforms.DefaultSpec())),
+		archive.WithSkipNonDistributableBlobs(),
+	}
+	is := i.client.ImageService()
+	for _, imageRef := range names {
+		named, err := reference.ParseDockerRef(imageRef)
+		if err != nil {
+			return err
+		}
+		opts = append(opts, archive.WithImage(is, named.String()))
+	}
+	return i.client.Export(ctx, outStream, opts...)
 }
 
 // LoadImage uploads a set of images into the repository. This is the
 // complement of ExportImage.  The input stream is an uncompressed tar
 // ball containing images and metadata.
-func (i *ImageService) LoadImage(inTar io.ReadCloser, outStream io.Writer, quiet bool) error {
-	panic("not implemented")
+func (i *ImageService) LoadImage(ctx context.Context, inTar io.ReadCloser, outStream io.Writer, quiet bool) error {
+	_, err := i.client.Import(ctx, inTar,
+		containerd.WithImportPlatform(platforms.DefaultStrict()),
+	)
+	return err
 }

daemon/image_service.go

@@ -29,8 +29,8 @@ type ImageService interface {
 	PushImage(ctx context.Context, image, tag string, metaHeaders map[string][]string, authConfig *registry.AuthConfig, outStream io.Writer) error
 	CreateImage(config []byte, parent string) (builder.Image, error)
 	ImageDelete(ctx context.Context, imageRef string, force, prune bool) ([]types.ImageDeleteResponseItem, error)
-	ExportImage(names []string, outStream io.Writer) error
-	LoadImage(inTar io.ReadCloser, outStream io.Writer, quiet bool) error
+	ExportImage(ctx context.Context, names []string, outStream io.Writer) error
+	LoadImage(ctx context.Context, inTar io.ReadCloser, outStream io.Writer, quiet bool) error
 	Images(ctx context.Context, opts types.ImageListOptions) ([]*types.ImageSummary, error)
 	LogImageEvent(imageID, refName, action string)
 	LogImageEventWithAttributes(imageID, refName, action string, attributes map[string]string)

daemon/images/image_exporter.go

@@ -1,6 +1,7 @@
 package images // import "github.com/docker/docker/daemon/images"
 
 import (
+	"context"
 	"io"
 
 	"github.com/docker/docker/image/tarexport"
@@ -11,7 +12,7 @@ import (
 // stream. All images with the given tag and all versions containing
 // the same tag are exported. names is the set of tags to export, and
 // outStream is the writer which the images are written to.
-func (i *ImageService) ExportImage(names []string, outStream io.Writer) error {
+func (i *ImageService) ExportImage(ctx context.Context, names []string, outStream io.Writer) error {
 	imageExporter := tarexport.NewTarExporter(i.imageStore, i.layerStore, i.referenceStore, i)
 	return imageExporter.Save(names, outStream)
 }
@@ -19,7 +20,7 @@ func (i *ImageService) ExportImage(names []string, outStream io.Writer) error {
 // LoadImage uploads a set of images into the repository. This is the
 // complement of ExportImage.  The input stream is an uncompressed tar
 // ball containing images and metadata.
-func (i *ImageService) LoadImage(inTar io.ReadCloser, outStream io.Writer, quiet bool) error {
+func (i *ImageService) LoadImage(ctx context.Context, inTar io.ReadCloser, outStream io.Writer, quiet bool) error {
 	imageExporter := tarexport.NewTarExporter(i.imageStore, i.layerStore, i.referenceStore, i)
 	return imageExporter.Load(inTar, outStream, quiet)
 }