Merge pull request #1880 from AkihiroSuda/refactor-importer

importer: refactor and fix GC

client.go

@@ -30,7 +30,6 @@ import (
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/plugin"
-	"github.com/containerd/containerd/reference"
 	"github.com/containerd/containerd/remotes"
 	"github.com/containerd/containerd/remotes/docker"
 	"github.com/containerd/containerd/remotes/docker/schema1"
@@ -503,95 +502,27 @@ func (c *Client) Version(ctx context.Context) (Version, error) {
 	}, nil
 }
 
-type imageFormat string
-
-const (
-	ociImageFormat imageFormat = "oci"
-)
-
 type importOpts struct {
-	format    imageFormat
-	refObject string
-	labels    map[string]string
 }
 
 // ImportOpt allows the caller to specify import specific options
 type ImportOpt func(c *importOpts) error
 
-// WithImportLabel sets a label to be associated with an imported image
-func WithImportLabel(key, value string) ImportOpt {
-	return func(opts *importOpts) error {
-		if opts.labels == nil {
-			opts.labels = make(map[string]string)
-		}
-
-		opts.labels[key] = value
-		return nil
-	}
-}
-
-// WithImportLabels associates a set of labels to an imported image
-func WithImportLabels(labels map[string]string) ImportOpt {
-	return func(opts *importOpts) error {
-		if opts.labels == nil {
-			opts.labels = make(map[string]string)
-		}
-
-		for k, v := range labels {
-			opts.labels[k] = v
-		}
-		return nil
-	}
-}
-
-// WithOCIImportFormat sets the import format for an OCI image format
-func WithOCIImportFormat() ImportOpt {
-	return func(c *importOpts) error {
-		if c.format != "" {
-			return errors.New("format already set")
-		}
-		c.format = ociImageFormat
-		return nil
-	}
-}
-
-// WithRefObject specifies the ref object to import.
-// If refObject is empty, it is copied from the ref argument of Import().
-func WithRefObject(refObject string) ImportOpt {
-	return func(c *importOpts) error {
-		c.refObject = refObject
-		return nil
-	}
-}
-
-func resolveImportOpt(ref string, opts ...ImportOpt) (importOpts, error) {
+func resolveImportOpt(opts ...ImportOpt) (importOpts, error) {
 	var iopts importOpts
 	for _, o := range opts {
 		if err := o(&iopts); err != nil {
 			return iopts, err
 		}
 	}
-	// use OCI as the default format
-	if iopts.format == "" {
-		iopts.format = ociImageFormat
-	}
-	// if refObject is not explicitly specified, use the one specified in ref
-	if iopts.refObject == "" {
-		refSpec, err := reference.Parse(ref)
-		if err != nil {
-			return iopts, err
-		}
-		iopts.refObject = refSpec.Object
-	}
 	return iopts, nil
 }
 
 // Import imports an image from a Tar stream using reader.
-// OCI format is assumed by default.
-//
-// Note that unreferenced blobs are imported to the content store as well.
-func (c *Client) Import(ctx context.Context, ref string, reader io.Reader, opts ...ImportOpt) (Image, error) {
-	iopts, err := resolveImportOpt(ref, opts...)
+// Caller needs to specify importer. Future version may use oci.v1 as the default.
+// Note that unreferrenced blobs may be imported to the content store as well.
+func (c *Client) Import(ctx context.Context, importer images.Importer, reader io.Reader, opts ...ImportOpt) ([]Image, error) {
+	_, err := resolveImportOpt(opts...) // unused now
 	if err != nil {
 		return nil, err
 	}
@@ -602,58 +533,66 @@ func (c *Client) Import(ctx context.Context, ref string, reader io.Reader, opts
 	}
 	defer done()
 
-	switch iopts.format {
-	case ociImageFormat:
-		return c.importFromOCITar(ctx, ref, reader, iopts)
-	default:
-		return nil, errors.Errorf("unsupported format: %s", iopts.format)
+	imgrecs, err := importer.Import(ctx, c.ContentStore(), reader)
+	if err != nil {
+		// is.Update() is not called on error
+		return nil, err
 	}
+
+	is := c.ImageService()
+	var images []Image
+	for _, imgrec := range imgrecs {
+		if updated, err := is.Update(ctx, imgrec, "target"); err != nil {
+			if !errdefs.IsNotFound(err) {
+				return nil, err
+			}
+
+			created, err := is.Create(ctx, imgrec)
+			if err != nil {
+				return nil, err
+			}
+
+			imgrec = created
+		} else {
+			imgrec = updated
+		}
+
+		images = append(images, &image{
+			client: c,
+			i:      imgrec,
+		})
+	}
+	return images, nil
 }
 
 type exportOpts struct {
-	format imageFormat
 }
 
-// ExportOpt allows callers to set export options
+// ExportOpt allows the caller to specify export-specific options
 type ExportOpt func(c *exportOpts) error
 
-// WithOCIExportFormat sets the OCI image format as the export target
-func WithOCIExportFormat() ExportOpt {
-	return func(c *exportOpts) error {
-		if c.format != "" {
-			return errors.New("format already set")
+func resolveExportOpt(opts ...ExportOpt) (exportOpts, error) {
+	var eopts exportOpts
+	for _, o := range opts {
+		if err := o(&eopts); err != nil {
+			return eopts, err
 		}
-		c.format = ociImageFormat
-		return nil
 	}
+	return eopts, nil
 }
 
-// TODO: add WithMediaTypeTranslation that transforms media types according to the format.
-// e.g. application/vnd.docker.image.rootfs.diff.tar.gzip
-//      -> application/vnd.oci.image.layer.v1.tar+gzip
-
 // Export exports an image to a Tar stream.
 // OCI format is used by default.
 // It is up to caller to put "org.opencontainers.image.ref.name" annotation to desc.
-func (c *Client) Export(ctx context.Context, desc ocispec.Descriptor, opts ...ExportOpt) (io.ReadCloser, error) {
-	var eopts exportOpts
-	for _, o := range opts {
-		if err := o(&eopts); err != nil {
-			return nil, err
-		}
-	}
-	// use OCI as the default format
-	if eopts.format == "" {
-		eopts.format = ociImageFormat
+// TODO(AkihiroSuda): support exporting multiple descriptors at once to a single archive stream.
+func (c *Client) Export(ctx context.Context, exporter images.Exporter, desc ocispec.Descriptor, opts ...ExportOpt) (io.ReadCloser, error) {
+	_, err := resolveExportOpt(opts...) // unused now
+	if err != nil {
+		return nil, err
 	}
 	pr, pw := io.Pipe()
-	switch eopts.format {
-	case ociImageFormat:
-		go func() {
-			pw.CloseWithError(c.exportToOCITar(ctx, desc, pw, eopts))
-		}()
-	default:
-		return nil, errors.Errorf("unsupported format: %s", eopts.format)
-	}
+	go func() {
+		pw.CloseWithError(exporter.Export(ctx, c.ContentStore(), desc, pw))
+	}()
 	return pr, nil
 }