fix ctr image export not found error

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

cmd/ctr/commands/images/export.go

@@ -21,7 +21,7 @@ import (
 	"os"
 
 	"github.com/containerd/containerd/cmd/ctr/commands"
-	oci "github.com/containerd/containerd/images/oci"
+	"github.com/containerd/containerd/images/oci"
 	"github.com/containerd/containerd/reference"
 	digest "github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -52,6 +52,10 @@ Currently, only OCI format is supported.
 			Usage: "media type of manifest digest",
 			Value: ocispec.MediaTypeImageManifest,
 		},
+		cli.BoolFlag{
+			Name:  "all-platforms",
+			Usage: "exports content from all platforms",
+		},
 	},
 	Action: func(context *cli.Context) error {
 		var (
@@ -101,7 +105,14 @@ Currently, only OCI format is supported.
 				return nil
 			}
 		}
-		r, err := client.Export(ctx, &oci.V1Exporter{}, desc)
+
+		var (
+			exportOpts []oci.V1ExporterOpt
+		)
+
+		exportOpts = append(exportOpts, oci.WithAllPlatforms(context.Bool("all-platforms")))
+
+		r, err := client.Export(ctx, desc, exportOpts...)
 		if err != nil {
 			return err
 		}

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"))

export_test.go

@@ -21,8 +21,6 @@ import (
 	"io"
 	"runtime"
 	"testing"
-
-	"github.com/containerd/containerd/images/oci"
 )
 
 // TestOCIExport exports testImage as a tar stream
@@ -44,7 +42,7 @@ func TestOCIExport(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	exportedStream, err := client.Export(ctx, &oci.V1Exporter{}, pulled.Target)
+	exportedStream, err := client.Export(ctx, pulled.Target)
 	if err != nil {
 		t.Fatal(err)
 	}

images/oci/exporter.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/platforms"
 	ocispecs "github.com/opencontainers/image-spec/specs-go"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
@@ -37,6 +38,36 @@ import (
 //                    e.g. application/vnd.docker.image.rootfs.diff.tar.gzip
 //                         -> application/vnd.oci.image.layer.v1.tar+gzip
 type V1Exporter struct {
+	AllPlatforms bool
+}
+
+// V1ExporterOpt allows to set  additional options to a newly V1Exporter
+type V1ExporterOpt func(c *V1Exporter) error
+
+// DefaultV1Exporter return a default V1Exporter pointer
+func DefaultV1Exporter() *V1Exporter {
+	return &V1Exporter{
+		AllPlatforms: false,
+	}
+}
+
+// ResolveV1ExportOpt return a new V1Exporter with V1ExporterOpt
+func ResolveV1ExportOpt(opts ...V1ExporterOpt) (*V1Exporter, error) {
+	exporter := DefaultV1Exporter()
+	for _, o := range opts {
+		if err := o(exporter); err != nil {
+			return exporter, err
+		}
+	}
+	return exporter, nil
+}
+
+// WithAllPlatforms set V1Exporter`s AllPlatforms option
+func WithAllPlatforms(allPlatforms bool) V1ExporterOpt {
+	return func(c *V1Exporter) error {
+		c.AllPlatforms = allPlatforms
+		return nil
+	}
 }
 
 // Export implements Exporter.
@@ -56,8 +87,19 @@ func (oe *V1Exporter) Export(ctx context.Context, store content.Provider, desc o
 		return nil, nil
 	}
 
+	childrenHandler := images.ChildrenHandler(store)
+
+	if !oe.AllPlatforms {
+		// get local default platform to fetch image manifest
+		p, err := platforms.Parse(platforms.DefaultString())
+		if err != nil {
+			return errors.Wrapf(err, "invalid platform %s", platforms.DefaultString())
+		}
+		childrenHandler = images.FilterPlatforms(childrenHandler, platforms.Any(p))
+	}
+
 	handlers := images.Handlers(
-		images.ChildrenHandler(store),
+		childrenHandler,
 		images.HandlerFunc(exportHandler),
 	)
 

import_test.go

@@ -29,7 +29,6 @@ import (
 	"github.com/containerd/containerd/archive/tartest"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/images/archive"
-	"github.com/containerd/containerd/images/oci"
 	digest "github.com/opencontainers/go-digest"
 	specs "github.com/opencontainers/image-spec/specs-go"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -56,7 +55,7 @@ func TestOCIExportAndImport(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	exported, err := client.Export(ctx, &oci.V1Exporter{}, pulled.Target)
+	exported, err := client.Export(ctx, pulled.Target)
 	if err != nil {
 		t.Fatal(err)
 	}