fix ctr image export not found error

Signed-off-by: Jie Zhang <iamkadisi@163.com>

export.go

@@ -20,36 +20,23 @@ import (
 	"context"
 	"io"
 
-	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/images/oci"
+
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 )
 
-type exportOpts struct {
-}
-
-// ExportOpt allows the caller to specify export-specific options
-type ExportOpt func(c *exportOpts) error
-
-func resolveExportOpt(opts ...ExportOpt) (exportOpts, error) {
-	var eopts exportOpts
-	for _, o := range opts {
-		if err := o(&eopts); err != nil {
-			return eopts, err
-		}
-	}
-	return eopts, nil
-}
-
 // 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.
 // 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
+func (c *Client) Export(ctx context.Context, desc ocispec.Descriptor, opts ...oci.V1ExporterOpt) (io.ReadCloser, error) {
+
+	exporter, err := oci.ResolveV1ExportOpt(opts...)
 	if err != nil {
 		return nil, err
 	}
+
 	pr, pw := io.Pipe()
 	go func() {
 		pw.CloseWithError(errors.Wrap(exporter.Export(ctx, c.ContentStore(), desc, pw), "export failed"))