support copy multi arch instance

copy/copy.go

@@ -92,8 +92,9 @@ type Options struct {
 	PreserveDigests bool
 	// manifest MIME type of image set by user. "" is default and means use the autodetection to the manifest MIME type
 	ForceManifestMIMEType string
-	ImageListSelection    ImageListSelection // set to either CopySystemImage (the default), CopyAllImages, or CopySpecificImages to control which instances we copy when the source reference is a list; ignored if the source reference is not a list
-	Instances             []digest.Digest    // if ImageListSelection is CopySpecificImages, copy only these instances and the list itself
+	ImageListSelection    ImageListSelection             // set to either CopySystemImage (the default), CopyAllImages, or CopySpecificImages to control which instances we copy when the source reference is a list; ignored if the source reference is not a list
+	ImageListPlatforms    []manifest.Schema2PlatformSpec // if ImageListSelection is CopySpecificImages, copy only these target platforms
+	Instances             []digest.Digest                // if ImageListSelection is CopySpecificImages, copy only these instances and the list itself, this is auto generated by ImageListPlatforms
 	// Give priority to pulling gzip images if multiple images are present when configured to OptionalBoolTrue,
 	// prefers the best compression if this is configured as OptionalBoolFalse. Choose automatically (and the choice may change over time)
 	// if this is set to OptionalBoolUndefined (which is the default behavior, and recommended for most callers).
@@ -325,6 +326,7 @@ func Image(ctx context.Context, policyContext *signature.PolicyContext, destRef,
 		if !supportsMultipleImages(c.dest) {
 			return nil, fmt.Errorf("copying multiple images: destination transport %q does not support copying multiple images as a group", destRef.Transport().Name())
 		}
+
 		// Copy some or all of the images.
 		switch c.options.ImageListSelection {
 		case CopyAllImages:

copy/multiple.go

@@ -60,8 +60,9 @@ func platformV1ToPlatformComparable(platform *imgspecv1.Platform) platformCompar
 	}
 	osFeatures := slices.Clone(platform.OSFeatures)
 	sort.Strings(osFeatures)
-	return platformComparable{architecture: platform.Architecture,
-		os: platform.OS,
+	return platformComparable{
+		architecture: platform.Architecture,
+		os:           platform.OS,
 		// This is strictly speaking ambiguous, fields of OSFeatures can contain a ','. Probably good enough for now.
 		osFeatures: strings.Join(osFeatures, ","),
 		osVersion:  platform.OSVersion,
@@ -98,8 +99,65 @@ func validateCompressionVariantExists(input []OptionCompressionVariant) error {
 	return nil
 }
 
+func isPlatformSupported(list internalManifest.List, platform manifest.Schema2PlatformSpec) (digest.Digest, bool) {
+	for _, instanceDigest := range list.Instances() {
+		instance, err := list.Instance(instanceDigest)
+		if err != nil {
+			return "", false
+		}
+
+		if instance.ReadOnly.Platform == nil {
+			continue
+		}
+
+		if instance.ReadOnly.Platform.OS == platform.OS &&
+			instance.ReadOnly.Platform.Architecture == platform.Architecture {
+			return instanceDigest, true
+		}
+	}
+
+	return "", false
+}
+
+func filterInstancesByPlatforms(list internalManifest.List, platforms []manifest.Schema2PlatformSpec) ([]digest.Digest, error) {
+	missingPlatforms := []manifest.Schema2PlatformSpec{}
+	supportedInstance := []digest.Digest{}
+	// Check each requested platform
+	for _, platform := range platforms {
+		if digest, ok := isPlatformSupported(list, platform); !ok {
+			missingPlatforms = append(missingPlatforms, platform)
+		} else {
+			supportedInstance = append(supportedInstance, digest)
+		}
+	}
+
+	if len(missingPlatforms) > 0 {
+		var platformStrings []string
+		for _, p := range missingPlatforms {
+			platformStr := fmt.Sprintf("%s/%s", p.OS, p.Architecture)
+			if p.Variant != "" {
+				platformStr += "/" + p.Variant
+			}
+			platformStrings = append(platformStrings, platformStr)
+		}
+		return nil, fmt.Errorf("requested platforms not found in image: %s", strings.Join(platformStrings, ", "))
+	}
+
+	if len(platforms) == 0 {
+		supportedInstance = list.Instances()
+	}
+
+	return supportedInstance, nil
+}
+
 // prepareInstanceCopies prepares a list of instances which needs to copied to the manifest list.
 func prepareInstanceCopies(list internalManifest.List, instanceDigests []digest.Digest, options *Options) ([]instanceCopy, error) {
+	filteredInstanceDigests, err := filterInstancesByPlatforms(list, options.ImageListPlatforms)
+	if err != nil {
+		return nil, err
+	}
+	options.Instances = filteredInstanceDigests
+
 	res := []instanceCopy{}
 	if options.ImageListSelection == CopySpecificImages && len(options.EnsureCompressionVariantsExist) > 0 {
 		// List can already contain compressed instance for a compression selected in `EnsureCompressionVariantsExist`
@@ -109,7 +167,8 @@ func prepareInstanceCopies(list internalManifest.List, instanceDigests []digest.
 		// We might define the semantics and implement this in the future.
 		return res, fmt.Errorf("EnsureCompressionVariantsExist is not implemented for CopySpecificImages")
 	}
-	err := validateCompressionVariantExists(options.EnsureCompressionVariantsExist)
+
+	err = validateCompressionVariantExists(options.EnsureCompressionVariantsExist)
 	if err != nil {
 		return res, err
 	}
@@ -252,15 +311,17 @@ func (c *copier) copyMultipleImages(ctx context.Context) (copiedManifest []byte,
 				UpdateDigest:                updated.manifestDigest,
 				UpdateSize:                  int64(len(updated.manifest)),
 				UpdateCompressionAlgorithms: updated.compressionAlgorithms,
-				UpdateMediaType:             updated.manifestMIMEType})
+				UpdateMediaType:             updated.manifestMIMEType,
+			})
 		case instanceCopyClone:
 			logrus.Debugf("Replicating instance %s (%d/%d)", instance.sourceDigest, i+1, len(instanceCopyList))
 			c.Printf("Replicating image %s (%d/%d)\n", instance.sourceDigest, i+1, len(instanceCopyList))
 			unparsedInstance := image.UnparsedInstance(c.rawSource, &instanceCopyList[i].sourceDigest)
 			updated, err := c.copySingleImage(ctx, unparsedInstance, &instanceCopyList[i].sourceDigest, copySingleImageOptions{
 				requireCompressionFormatMatch: true,
 				compressionFormat:             &instance.cloneCompressionVariant.Algorithm,
-				compressionLevel:              instance.cloneCompressionVariant.Level})
+				compressionLevel:              instance.cloneCompressionVariant.Level,
+			})
 			if err != nil {
 				return nil, fmt.Errorf("replicating image %d/%d from manifest list: %w", i+1, len(instanceCopyList), err)
 			}
@@ -285,6 +346,21 @@ func (c *copier) copyMultipleImages(ctx context.Context) (copiedManifest []byte,
 		return nil, fmt.Errorf("updating manifest list: %w", err)
 	}
 
+	if len(c.options.Instances) > 0 {
+		deletedInstanceDigests := []internalManifest.ListEdit{}
+		for _, instanceDigest := range updatedList.Instances() {
+			if !slices.Contains(c.options.Instances, instanceDigest) {
+				deletedInstanceDigests = append(deletedInstanceDigests, internalManifest.ListEdit{
+					ListOperation:   internalManifest.ListOpRemove,
+					UpdateOldDigest: instanceDigest,
+				})
+			}
+		}
+		if err = updatedList.EditInstances(deletedInstanceDigests); err != nil {
+			return nil, fmt.Errorf("updating manifest list: %w", err)
+		}
+	}
+
 	// Iterate through supported list types, preferred format first.
 	c.Printf("Writing manifest list to image destination\n")
 	var errs []string

internal/manifest/docker_schema2_list.go

@@ -82,7 +82,8 @@ func (index *Schema2ListPublic) UpdateInstances(updates []ListUpdate) error {
 			UpdateDigest:    instance.Digest,
 			UpdateSize:      instance.Size,
 			UpdateMediaType: instance.MediaType,
-			ListOperation:   ListOpUpdate})
+			ListOperation:   ListOpUpdate,
+		})
 	}
 	return index.editInstances(editInstances)
 }
@@ -128,6 +129,14 @@ func (index *Schema2ListPublic) editInstances(editInstances []ListEdit) error {
 				},
 				schema2PlatformSpecFromOCIPlatform(*editInstance.AddPlatform),
 			})
+		case ListOpRemove:
+			targetIndex := slices.IndexFunc(index.Manifests, func(m Schema2ManifestDescriptor) bool {
+				return m.Digest == editInstance.UpdateOldDigest
+			})
+			if targetIndex == -1 {
+				return fmt.Errorf("Schema2List.EditInstances: digest %s not found", editInstance.UpdateOldDigest)
+			}
+			index.Manifests = append(index.Manifests[:targetIndex], index.Manifests[targetIndex+1:]...)
 		default:
 			return fmt.Errorf("internal error: invalid operation: %d", editInstance.ListOperation)
 		}

internal/manifest/list.go

@@ -83,6 +83,7 @@ const (
 	listOpInvalid ListOp = iota
 	ListOpAdd
 	ListOpUpdate
+	ListOpRemove
 )
 
 // ListEdit includes the fields which a List's EditInstances() method will modify.

internal/manifest/oci_index.go

@@ -79,7 +79,8 @@ func (index *OCI1IndexPublic) UpdateInstances(updates []ListUpdate) error {
 			UpdateDigest:    instance.Digest,
 			UpdateSize:      instance.Size,
 			UpdateMediaType: instance.MediaType,
-			ListOperation:   ListOpUpdate})
+			ListOperation:   ListOpUpdate,
+		})
 	}
 	return index.editInstances(editInstances)
 }
@@ -166,6 +167,15 @@ func (index *OCI1IndexPublic) editInstances(editInstances []ListEdit) error {
 				Platform:     editInstance.AddPlatform,
 				Annotations:  annotations,
 			})
+		case ListOpRemove:
+			targetIndex := slices.IndexFunc(index.Manifests, func(m imgspecv1.Descriptor) bool {
+				return m.Digest == editInstance.UpdateOldDigest
+			})
+
+			if targetIndex == -1 {
+				return fmt.Errorf("OCI1Index.EditInstances: digest %s not found", editInstance.UpdateOldDigest)
+			}
+			index.Manifests = append(index.Manifests[:targetIndex], index.Manifests[targetIndex+1:]...)
 		default:
 			return fmt.Errorf("internal error: invalid operation: %d", editInstance.ListOperation)
 		}