fix(oci): bad parse oci_ref when used with custom registry

cmd/rc-steering/rc-steering.go

@@ -27,7 +27,7 @@ var (
 func main() {
 	var mqttBroker, username, password, clientId string
 	var cameraTopic, steeringTopic string
-	var modelPath, modelsDir, ociRef string
+	var modelPath, modelsDir, ociRegistry, ociRepository, ociTag string
 	var edgeVerbosity int
 	var imgWidth, imgHeight, horizon int
 
@@ -37,7 +37,9 @@ func main() {
 	cli.InitMqttFlags(DefaultClientId, &mqttBroker, &username, &password, &clientId, &mqttQos, &mqttRetain)
 
 	flag.StringVar(&modelPath, "model", "", "path to model file")
-	flag.StringVar(&ociRef, "oci-model", "", "oci image to pull")
+	flag.StringVar(&ociRegistry, "oci-model-registry", "", "oci registry where to fetch model")
+	flag.StringVar(&ociRepository, "oci-model-repository", "", "oci repository where to fetch model")
+	flag.StringVar(&ociTag, "oci-model-tag", "", "oci tag name for model to pull")
 	flag.StringVar(&modelsDir, "models-dir", "/tmp/robocar/models", "path where to store model file")
 	flag.StringVar(&steeringTopic, "mqtt-topic-road", os.Getenv("MQTT_TOPIC_STEERING"), "Mqtt topic to publish road detection result, use MQTT_TOPIC_STEERING if args not set")
 	flag.StringVar(&cameraTopic, "mqtt-topic-camera", os.Getenv("MQTT_TOPIC_CAMERA"), "Mqtt topic that contains camera frame values, use MQTT_TOPIC_CAMERA if args not set")
@@ -68,12 +70,12 @@ func main() {
 
 	cleanup := metrics.Init(context.Background())
 	defer cleanup()
-	if modelPath == "" && ociRef == "" {
+	if modelPath == "" && ociRepository == "" {
 		zap.L().Error("model path or oci image is mandatory")
 		flag.PrintDefaults()
 		os.Exit(1)
 	}
-	if modelPath != "" && ociRef != "" {
+	if modelPath != "" && ociRepository != "" {
 		zap.L().Error("model path and oci image are exclusives")
 		flag.PrintDefaults()
 		os.Exit(1)
@@ -88,7 +90,8 @@ func main() {
 			zap.S().Panicf("bad model name '%v', unable to detect configuration from name pattern: %v", modelPath, err)
 		}
 	} else {
-		modelPath, modelType, width, height, horizonFromName, err = oci.PullOciImage(ociRef, modelsDir)
+		ctx := context.Background()
+		modelPath, modelType, width, height, horizonFromName, err = oci.PullOciImage(ctx, ociRegistry, ociRepository, ociTag, modelsDir)
 		if err != nil {
 			zap.S().Panicf("bad model name '%v', unable to detect configuration from name pattern: %v", modelPath, err)
 		}
@@ -110,10 +113,10 @@ func main() {
 		os.Exit(1)
 	}
 
-	if ociRef == "" {
+	if ociRepository == "" {
 		zap.S().Infof("model path            : %v", modelPath)
 	} else {
-		zap.S().Infof("oci image model       : %v", ociRef)
+		zap.S().Infof("oci image model       : %v/%v:%v", ociRegistry, ociRepository, ociTag)
 	}
 	zap.S().Infof("model type            : %v", modelType)
 	zap.S().Infof("model for image width : %v", imgWidth)

go.mod

@@ -14,7 +14,7 @@ require (
 	go.opentelemetry.io/otel/sdk/metric v0.30.0
 	go.uber.org/zap v1.21.0
 	google.golang.org/protobuf v1.28.1
-	oras.land/oras-go/v2 v2.0.2
+	oras.land/oras-go/v2 v2.2.0
 )
 
 require (
@@ -31,7 +31,7 @@ require (
 	go.uber.org/multierr v1.6.0 // indirect
 	golang.org/x/image v0.0.0-20220601225756-64ec528b34cd // indirect
 	golang.org/x/net v0.8.0 // indirect
-	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sync v0.2.0 // indirect
 	golang.org/x/sys v0.6.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )

go.sum

@@ -84,8 +84,8 @@ golang.org/x/net v0.8.0 h1:Zrh2ngAOFYneWTAIAPethzeaQLuHwhuBkuV6ZiRnUaQ=
 golang.org/x/net v0.8.0/go.mod h1:QVkue5JL9kW//ek3r6jTKnTFis1tRmNAW2P1shuFdJc=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.2.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -119,5 +119,5 @@ gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
-oras.land/oras-go/v2 v2.0.2 h1:3aSQdJ7EUC0ft2e9PjJB9Jzastz5ojPA4LzZ3Q4YbUc=
+oras.land/oras-go/v2 v2.2.0 h1:E1fqITD56Eg5neZbxBtAdZVgDHD6wBabJo6xESTcQyo=
-oras.land/oras-go/v2 v2.0.2/go.mod h1:PWnWc/Kyyg7wUTUsDHshrsJkzuxXzreeMd6NrfdnFSo=
+oras.land/oras-go/v2 v2.2.0/go.mod h1:pXjn0+KfarspMHHNR3A56j3tgvr+mxArHuI8qVn59v8=

pkg/oci/models.go

@@ -6,26 +6,31 @@ import (
 	"fmt"
 	"github.com/cyrilix/robocar-steering-tflite-edgetpu/pkg/tools"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
+	"go.uber.org/zap"
+	"oras.land/oras-go/v2"
 	"oras.land/oras-go/v2/content"
+	"oras.land/oras-go/v2/content/file"
+	"oras.land/oras-go/v2/registry"
+	"oras.land/oras-go/v2/registry/remote"
 	"path"
 	"strconv"
-	"strings"
-
-	"oras.land/oras-go/v2"
-	"oras.land/oras-go/v2/content/file"
-	"oras.land/oras-go/v2/registry/remote"
 )
 
-func PullOciImage(ociRef string, modelsDir string) (modelPath string, modelType tools.ModelType, imgWidth, imgHeight int, horizon int, err error) {
+func PullOciImage(ctx context.Context, regName, repoName, tag, modelsDir string) (modelPath string, modelType tools.ModelType, imgWidth, imgHeight int, horizon int, err error) {
-	repository := strings.Split(ociRef, ":")[0]
-	tag := strings.Split(ociRef, ":")[1]
 
-	manifest, err := fetchManifest(repository, tag)
+	repo, err := getRepository(ctx, regName, repoName)
 	if err != nil {
-		err = fmt.Errorf("unable to fetch manifest '%s': %w", ociRef, err)
+		err = fmt.Errorf("unable to fetch oci artifact from '%s/%s: %w", regName, repoName, err)
 		return
 	}
 
+	manifest, err := fetchManifest(ctx, repo, tag)
+	if err != nil {
+		err = fmt.Errorf("unable to fetch manifest '%s/%s:%s': %w", regName, repoName, tag, err)
+		return
+	}
+	zap.S().Infof("Manifest: %v", manifest)
+
 	// 0. Create a file store
 	modelStore := path.Join(modelsDir, manifest.Annotations["category"])
 	fs, err := file.New(modelStore)
@@ -34,14 +39,7 @@ func PullOciImage(ociRef string, modelsDir string) (modelPath string, modelType
 	}
 	defer fs.Close()
 
-	// 1. Connect to a remote repository
+	// 2. Copy from the remote repoName to the file store
-	ctx := context.Background()
-	repo, err := remote.NewRepository(repository)
-	if err != nil {
-		return
-	}
-
-	// 2. Copy from the remote repository to the file store
 	_, err = oras.Copy(ctx, repo, tag, fs, tag, oras.DefaultCopyOptions)
 	if err != nil {
 		return
@@ -70,31 +68,60 @@ func PullOciImage(ociRef string, modelsDir string) (modelPath string, modelType
 	return
 }
 
-func fetchManifest(repository string, tag string) (*v1.Manifest, error) {
+func getRepository(ctx context.Context, registryName string, repoName string) (registry.Repository, error) {
-	repo, err := remote.NewRepository(repository)
+
+	reg, err := remote.NewRegistry(registryName)
 	if err != nil {
-		panic(err)
+		return nil, fmt.Errorf("bad registry '%v': %w", registryName, err)
 	}
-	ctx := context.Background()
+	reg.RepositoryOptions.PlainHTTP = true
+
+	// For debug
+	//reg.Repositories(ctx, "", func(repos []string) error {
+	//	for _, r := range repos {
+	//		zap.S().Debugf("found repo %v", r)
+	//	}
+	//	return nil
+	//})
+
+	repo, err := reg.Repository(ctx, repoName)
+	if err != nil {
+		return nil, fmt.Errorf("unable to instanciate new repository: %w", err)
+	}
+
+	// For debug
+	/*
+		repo.Tags(ctx, "", func(tags []string) error {
+			for _, t := range tags {
+				zap.S().Debugf("found tag '%v'", t)
+			}
+			return nil
+		})
+	*/
+	return repo, nil
+}
+
+func fetchManifest(ctx context.Context, repo registry.Repository, tag string) (*v1.Manifest, error) {
 
 	descriptor, err := repo.Resolve(ctx, tag)
+	zap.S().Debugf("model descriptor: %#v", descriptor)
 	if err != nil {
-		panic(err)
+		return nil, fmt.Errorf("unexpected error on tag resolving: %w", err)
 	}
 	rc, err := repo.Fetch(ctx, descriptor)
 	if err != nil {
-		return nil, fmt.Errorf("unable to fetch manifest for image '%s:%s': %w", repository, tag, err)
+		return nil, fmt.Errorf("unable to fetch manifest for image '%s:%s': %w", repo, tag, err)
 	}
 	defer rc.Close() // don't forget to close
 	pulledBlob, err := content.ReadAll(rc, descriptor)
 	if err != nil {
-		return nil, fmt.Errorf("unable to read manifest content for image '%s:%s': %w", repository, tag, err)
+		return nil, fmt.Errorf("unable to read manifest content for image '%s:%s': %w", repo, tag, err)
 	}
 
 	var manifest v1.Manifest
 	err = json.Unmarshal(pulledBlob, &manifest)
 	if err != nil {
-		return nil, fmt.Errorf("unable to unmarsh json manifest content for image '%s:%s': %w", repository, tag, err)
+		return nil, fmt.Errorf("unable to unmarsh json manifest content for image '%s:%s': %w", repo, tag, err)
 	}
 	return &manifest, nil
 }

vendor/modules.txt

@@ -114,7 +114,7 @@ golang.org/x/image/tiff/lzw
 ## explicit; go 1.17
 golang.org/x/net/internal/socks
 golang.org/x/net/proxy
-# golang.org/x/sync v0.1.0
+# golang.org/x/sync v0.2.0
 ## explicit
 golang.org/x/sync/errgroup
 golang.org/x/sync/semaphore
@@ -154,7 +154,7 @@ google.golang.org/protobuf/runtime/protoimpl
 google.golang.org/protobuf/types/known/timestamppb
 # gopkg.in/yaml.v2 v2.4.0
 ## explicit; go 1.15
-# oras.land/oras-go/v2 v2.0.2
+# oras.land/oras-go/v2 v2.2.0
 ## explicit; go 1.19
 oras.land/oras-go/v2
 oras.land/oras-go/v2/content
@@ -173,6 +173,7 @@ oras.land/oras-go/v2/internal/platform
 oras.land/oras-go/v2/internal/registryutil
 oras.land/oras-go/v2/internal/resolver
 oras.land/oras-go/v2/internal/slices
+oras.land/oras-go/v2/internal/spec
 oras.land/oras-go/v2/internal/status
 oras.land/oras-go/v2/internal/syncutil
 oras.land/oras-go/v2/registry

vendor/oras.land/oras-go/v2/.gitignore

@@ -38,3 +38,4 @@ dist/
 *.tar.gz
 vendor/
 _dist/
+.cover

vendor/oras.land/oras-go/v2/README.md

@@ -1,6 +1,8 @@
 # ORAS Go library
 
-![ORAS](https://github.com/oras-project/oras-www/raw/main/docs/assets/images/oras.png)
+<p align="left">
+<a href="https://oras.land/"><img src="https://oras.land/img/oras.svg" alt="banner" width="100px"></a>
+</p>
 
 ## Project status
 
@@ -45,7 +47,7 @@ to use releases with major version `2` for new features.
 
 ## Docs
 
-- [oras.land/client_libraries/go](https://oras.land/client_libraries/0_go/): Documentation for the ORAS Go library
+- [oras.land/client_libraries/go](https://oras.land/docs/Client_Libraries/go): Documentation for the ORAS Go library
 - [Reviewing guide](https://github.com/oras-project/community/blob/main/REVIEWING.md): All reviewers must read the reviewing guide and agree to follow the project review guidelines.
 
 ## Code of Conduct

vendor/oras.land/oras-go/v2/content/graph.go

@@ -21,6 +21,7 @@ import (
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/internal/docker"
+	"oras.land/oras-go/v2/internal/spec"
 )
 
 // PredecessorFinder finds out the nodes directly pointing to a given node of a
@@ -86,13 +87,13 @@ func Successors(ctx context.Context, fetcher Fetcher, node ocispec.Descriptor) (
 			return nil, err
 		}
 		return index.Manifests, nil
-	case ocispec.MediaTypeArtifactManifest:
+	case spec.MediaTypeArtifactManifest:
 		content, err := FetchAll(ctx, fetcher, node)
 		if err != nil {
 			return nil, err
 		}
 
-		var manifest ocispec.Artifact
+		var manifest spec.Artifact
 		if err := json.Unmarshal(content, &manifest); err != nil {
 			return nil, err
 		}

vendor/oras.land/oras-go/v2/extendedcopy.go

@@ -29,6 +29,7 @@ import (
 	"oras.land/oras-go/v2/internal/copyutil"
 	"oras.land/oras-go/v2/internal/descriptor"
 	"oras.land/oras-go/v2/internal/docker"
+	"oras.land/oras-go/v2/internal/spec"
 	"oras.land/oras-go/v2/internal/status"
 	"oras.land/oras-go/v2/internal/syncutil"
 	"oras.land/oras-go/v2/registry"
@@ -255,7 +256,7 @@ func (opts *ExtendedCopyGraphOptions) FilterAnnotation(key string, regex *regexp
 				switch p.MediaType {
 				case docker.MediaTypeManifest, ocispec.MediaTypeImageManifest,
 					docker.MediaTypeManifestList, ocispec.MediaTypeImageIndex,
-					ocispec.MediaTypeArtifactManifest:
+					spec.MediaTypeArtifactManifest:
 					annotations, err := fetchAnnotations(ctx, src, p)
 					if err != nil {
 						return nil, err
@@ -345,7 +346,7 @@ func (opts *ExtendedCopyGraphOptions) FilterArtifactType(regex *regexp.Regexp) {
 				// if the artifact type is not present in the descriptors,
 				// fetch it from the manifest content.
 				switch p.MediaType {
-				case ocispec.MediaTypeArtifactManifest, ocispec.MediaTypeImageManifest:
+				case spec.MediaTypeArtifactManifest, ocispec.MediaTypeImageManifest:
 					artifactType, err := fetchArtifactType(ctx, src, p)
 					if err != nil {
 						return nil, err
@@ -370,8 +371,8 @@ func fetchArtifactType(ctx context.Context, src content.ReadOnlyGraphStorage, de
 	defer rc.Close()
 
 	switch desc.MediaType {
-	case ocispec.MediaTypeArtifactManifest:
+	case spec.MediaTypeArtifactManifest:
-		var manifest ocispec.Artifact
+		var manifest spec.Artifact
 		if err := json.NewDecoder(rc).Decode(&manifest); err != nil {
 			return "", err
 		}

vendor/oras.land/oras-go/v2/internal/descriptor/descriptor.go

@@ -19,6 +19,7 @@ import (
 	"github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/internal/docker"
+	"oras.land/oras-go/v2/internal/spec"
 )
 
 // DefaultMediaType is the media type used when no media type is specified.
@@ -70,7 +71,7 @@ func IsManifest(desc ocispec.Descriptor) bool {
 		docker.MediaTypeManifestList,
 		ocispec.MediaTypeImageManifest,
 		ocispec.MediaTypeImageIndex,
-		ocispec.MediaTypeArtifactManifest:
+		spec.MediaTypeArtifactManifest:
 		return true
 	default:
 		return false

vendor/oras.land/oras-go/v2/internal/spec/artifact.go

@@ -0,0 +1,49 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package spec
+
+import ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+
+// AnnotationReferrersFiltersApplied is the annotation key for the comma separated list of filters applied by the registry in the referrers listing.
+const AnnotationReferrersFiltersApplied = "org.opencontainers.referrers.filtersApplied"
+
+// MediaTypeArtifactManifest specifies the media type for a content descriptor.
+const MediaTypeArtifactManifest = "application/vnd.oci.artifact.manifest.v1+json"
+
+// Artifact describes an artifact manifest.
+// This structure provides `application/vnd.oci.artifact.manifest.v1+json` mediatype when marshalled to JSON.
+//
+// This manifest type was introduced in image-spec v1.1.0-rc1 and was removed in
+// image-spec v1.1.0-rc3. It is not part of the current image-spec and is kept
+// here for Go compatibility.
+//
+// Reference: https://github.com/opencontainers/image-spec/pull/999
+type Artifact struct {
+	// MediaType is the media type of the object this schema refers to.
+	MediaType string `json:"mediaType"`
+
+	// ArtifactType is the IANA media type of the artifact this schema refers to.
+	ArtifactType string `json:"artifactType"`
+
+	// Blobs is a collection of blobs referenced by this manifest.
+	Blobs []ocispec.Descriptor `json:"blobs,omitempty"`
+
+	// Subject (reference) is an optional link from the artifact to another manifest forming an association between the artifact and the other manifest.
+	Subject *ocispec.Descriptor `json:"subject,omitempty"`
+
+	// Annotations contains arbitrary metadata for the artifact manifest.
+	Annotations map[string]string `json:"annotations,omitempty"`
+}

vendor/oras.land/oras-go/v2/pack.go

@@ -27,6 +27,7 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/content"
 	"oras.land/oras-go/v2/errdef"
+	"oras.land/oras-go/v2/internal/spec"
 )
 
 const (
@@ -93,8 +94,8 @@ func packArtifact(ctx context.Context, pusher content.Pusher, artifactType strin
 	if err != nil {
 		return ocispec.Descriptor{}, err
 	}
-	manifest := ocispec.Artifact{
+	manifest := spec.Artifact{
-		MediaType:    ocispec.MediaTypeArtifactManifest,
+		MediaType:    spec.MediaTypeArtifactManifest,
 		ArtifactType: artifactType,
 		Blobs:        blobs,
 		Subject:      opts.Subject,
@@ -104,7 +105,7 @@ func packArtifact(ctx context.Context, pusher content.Pusher, artifactType strin
 	if err != nil {
 		return ocispec.Descriptor{}, fmt.Errorf("failed to marshal manifest: %w", err)
 	}
-	manifestDesc := content.NewDescriptorFromBytes(ocispec.MediaTypeArtifactManifest, manifestJSON)
+	manifestDesc := content.NewDescriptorFromBytes(spec.MediaTypeArtifactManifest, manifestJSON)
 	// populate ArtifactType and Annotations of the manifest into manifestDesc
 	manifestDesc.ArtifactType = manifest.ArtifactType
 	manifestDesc.Annotations = manifest.Annotations

vendor/oras.land/oras-go/v2/registry/remote/auth/client.go

@@ -56,6 +56,12 @@ var defaultClientID = "oras-go"
 
 // StaticCredential specifies static credentials for the given host.
 func StaticCredential(registry string, cred Credential) func(context.Context, string) (Credential, error) {
+	if registry == "docker.io" {
+		// it is expected that traffic targeting "docker.io" will be redirected
+		// to "registry-1.docker.io"
+		// reference: https://github.com/moby/moby/blob/v24.0.0-beta.2/registry/config.go#L25-L48
+		registry = "registry-1.docker.io"
+	}
 	return func(_ context.Context, target string) (Credential, error) {
 		if target == registry {
 			return cred, nil

vendor/oras.land/oras-go/v2/registry/remote/manifest.go

@@ -20,6 +20,7 @@ import (
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/internal/docker"
+	"oras.land/oras-go/v2/internal/spec"
 )
 
 // defaultManifestMediaTypes contains the default set of manifests media types.
@@ -28,7 +29,7 @@ var defaultManifestMediaTypes = []string{
 	docker.MediaTypeManifestList,
 	ocispec.MediaTypeImageManifest,
 	ocispec.MediaTypeImageIndex,
-	ocispec.MediaTypeArtifactManifest,
+	spec.MediaTypeArtifactManifest,
 }
 
 // defaultManifestAcceptHeader is the default set in the `Accept` header for

vendor/oras.land/oras-go/v2/registry/remote/referrers.go

@@ -22,6 +22,7 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/v2/content"
 	"oras.land/oras-go/v2/internal/descriptor"
+	"oras.land/oras-go/v2/internal/spec"
 )
 
 // zeroDigest represents a digest that consists of zeros. zeroDigest is used
@@ -68,6 +69,38 @@ var (
 	errNoReferrerUpdate = errors.New("no referrer update")
 )
 
+const (
+	// opDeleteReferrersIndex represents the operation for deleting a
+	// referrers index.
+	opDeleteReferrersIndex = "DeleteReferrersIndex"
+)
+
+// ReferrersError records an error and the operation and the subject descriptor.
+type ReferrersError struct {
+	// Op represents the failing operation.
+	Op string
+	// Subject is the descriptor of referenced artifact.
+	Subject ocispec.Descriptor
+	// Err is the entity of referrers error.
+	Err error
+}
+
+// Error returns error msg of IgnorableError.
+func (e *ReferrersError) Error() string {
+	return e.Err.Error()
+}
+
+// Unwrap returns the inner error of IgnorableError.
+func (e *ReferrersError) Unwrap() error {
+	return errors.Unwrap(e.Err)
+}
+
+// IsIndexDelete tells if e is kind of error related to referrers
+// index deletion.
+func (e *ReferrersError) IsReferrersIndexDelete() bool {
+	return e.Op == opDeleteReferrersIndex
+}
+
 // buildReferrersTag builds the referrers tag for the given manifest descriptor.
 // Format: <algorithm>-<digest>
 // Reference: https://github.com/opencontainers/distribution-spec/blob/v1.1.0-rc1/spec.md#unavailable-referrers-api
@@ -80,7 +113,7 @@ func buildReferrersTag(desc ocispec.Descriptor) string {
 // isReferrersFilterApplied checks annotations to see if requested is in the
 // applied filter list.
 func isReferrersFilterApplied(annotations map[string]string, requested string) bool {
-	applied := annotations[ocispec.AnnotationReferrersFiltersApplied]
+	applied := annotations[spec.AnnotationReferrersFiltersApplied]
 	if applied == "" || requested == "" {
 		return false
 	}

vendor/oras.land/oras-go/v2/registry/remote/repository.go

@@ -39,6 +39,7 @@ import (
 	"oras.land/oras-go/v2/internal/ioutil"
 	"oras.land/oras-go/v2/internal/registryutil"
 	"oras.land/oras-go/v2/internal/slices"
+	"oras.land/oras-go/v2/internal/spec"
 	"oras.land/oras-go/v2/internal/syncutil"
 	"oras.land/oras-go/v2/registry"
 	"oras.land/oras-go/v2/registry/remote/auth"
@@ -213,6 +214,19 @@ func (r *Repository) Push(ctx context.Context, expected ocispec.Descriptor, cont
 	return r.blobStore(expected).Push(ctx, expected, content)
 }
 
+// Mount makes the blob with the given digest in fromRepo
+// available in the repository signified by the receiver.
+//
+// This avoids the need to pull content down from fromRepo only to push it to r.
+//
+// If the registry does not implement mounting, getContent will be used to get the
+// content to push. If getContent is nil, the content will be pulled from the source
+// repository. If getContent returns an error, it will be wrapped inside the error
+// returned from Mount.
+func (r *Repository) Mount(ctx context.Context, desc ocispec.Descriptor, fromRepo string, getContent func() (io.ReadCloser, error)) error {
+	return r.Blobs().(registry.Mounter).Mount(ctx, desc, fromRepo, getContent)
+}
+
 // Exists returns true if the described content exists.
 func (r *Repository) Exists(ctx context.Context, target ocispec.Descriptor) (bool, error) {
 	return r.blobStore(target).Exists(ctx, target)
@@ -659,6 +673,73 @@ func (s *blobStore) Fetch(ctx context.Context, target ocispec.Descriptor) (rc io
 	}
 }
 
+// Mount mounts the given descriptor from fromRepo into s.
+func (s *blobStore) Mount(ctx context.Context, desc ocispec.Descriptor, fromRepo string, getContent func() (io.ReadCloser, error)) error {
+	// pushing usually requires both pull and push actions.
+	// Reference: https://github.com/distribution/distribution/blob/v2.7.1/registry/handlers/app.go#L921-L930
+	ctx = registryutil.WithScopeHint(ctx, s.repo.Reference, auth.ActionPull, auth.ActionPush)
+
+	// We also need pull access to the source repo.
+	fromRef := s.repo.Reference
+	fromRef.Repository = fromRepo
+	ctx = registryutil.WithScopeHint(ctx, fromRef, auth.ActionPull)
+
+	url := buildRepositoryBlobMountURL(s.repo.PlainHTTP, s.repo.Reference, desc.Digest, fromRepo)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := s.repo.client().Do(req)
+	if err != nil {
+		return err
+	}
+	if resp.StatusCode == http.StatusCreated {
+		defer resp.Body.Close()
+		// Check the server seems to be behaving.
+		return verifyContentDigest(resp, desc.Digest)
+	}
+	if resp.StatusCode != http.StatusAccepted {
+		defer resp.Body.Close()
+		return errutil.ParseErrorResponse(resp)
+	}
+	resp.Body.Close()
+	// From the [spec]:
+	//
+	// "If a registry does not support cross-repository mounting
+	// or is unable to mount the requested blob,
+	// it SHOULD return a 202.
+	// This indicates that the upload session has begun
+	// and that the client MAY proceed with the upload."
+	//
+	// So we need to get the content from somewhere in order to
+	// push it. If the caller has provided a getContent function, we
+	// can use that, otherwise pull the content from the source repository.
+	//
+	// [spec]: https://github.com/opencontainers/distribution-spec/blob/main/spec.md#mounting-a-blob-from-another-repository
+
+	var r io.ReadCloser
+	if getContent != nil {
+		r, err = getContent()
+	} else {
+		r, err = s.sibling(fromRepo).Fetch(ctx, desc)
+	}
+	if err != nil {
+		return fmt.Errorf("cannot read source blob: %w", err)
+	}
+	defer r.Close()
+	return s.completePushAfterInitialPost(ctx, req, resp, desc, r)
+}
+
+// sibling returns a blob store for another repository in the same
+// registry.
+func (s *blobStore) sibling(otherRepoName string) *blobStore {
+	otherRepo := *s.repo
+	otherRepo.Reference.Repository = otherRepoName
+	return &blobStore{
+		repo: &otherRepo,
+	}
+}
+
 // Push pushes the content, matching the expected descriptor.
 // Existing content is not checked by Push() to minimize the number of out-going
 // requests.
@@ -679,11 +760,8 @@ func (s *blobStore) Push(ctx context.Context, expected ocispec.Descriptor, conte
 	if err != nil {
 		return err
 	}
-	reqHostname := req.URL.Hostname()
-	reqPort := req.URL.Port()
 
-	client := s.repo.client()
+	resp, err := s.repo.client().Do(req)
-	resp, err := client.Do(req)
 	if err != nil {
 		return err
 	}
@@ -693,7 +771,15 @@ func (s *blobStore) Push(ctx context.Context, expected ocispec.Descriptor, conte
 		return errutil.ParseErrorResponse(resp)
 	}
 	resp.Body.Close()
+	return s.completePushAfterInitialPost(ctx, req, resp, expected, content)
+}
 
+// completePushAfterInitialPost implements step 2 of the push protocol. This can be invoked either by
+// Push or by Mount when the receiving repository does not implement the
+// mount endpoint.
+func (s *blobStore) completePushAfterInitialPost(ctx context.Context, req *http.Request, resp *http.Response, expected ocispec.Descriptor, content io.Reader) error {
+	reqHostname := req.URL.Hostname()
+	reqPort := req.URL.Port()
 	// monolithic upload
 	location, err := resp.Location()
 	if err != nil {
@@ -710,7 +796,7 @@ func (s *blobStore) Push(ctx context.Context, expected ocispec.Descriptor, conte
 	if reqPort == "443" && locationHostname == reqHostname && locationPort == "" {
 		location.Host = locationHostname + ":" + reqPort
 	}
-	url = location.String()
+	url := location.String()
 	req, err = http.NewRequestWithContext(ctx, http.MethodPut, url, content)
 	if err != nil {
 		return err
@@ -730,7 +816,7 @@ func (s *blobStore) Push(ctx context.Context, expected ocispec.Descriptor, conte
 	if auth := resp.Request.Header.Get("Authorization"); auth != "" {
 		req.Header.Set("Authorization", auth)
 	}
-	resp, err = client.Do(req)
+	resp, err = s.repo.client().Do(req)
 	if err != nil {
 		return err
 	}
@@ -946,7 +1032,7 @@ func (s *manifestStore) Delete(ctx context.Context, target ocispec.Descriptor) e
 // deleteWithIndexing removes the manifest content identified by the descriptor,
 // and indexes referrers for the manifest when needed.
 func (s *manifestStore) deleteWithIndexing(ctx context.Context, target ocispec.Descriptor) error {
-	if target.MediaType == ocispec.MediaTypeArtifactManifest || target.MediaType == ocispec.MediaTypeImageManifest {
+	if target.MediaType == spec.MediaTypeArtifactManifest || target.MediaType == ocispec.MediaTypeImageManifest {
 		if state := s.repo.loadReferrersState(); state == referrersStateSupported {
 			// referrers API is available, no client-side indexing needed
 			return s.repo.delete(ctx, target, true)
@@ -1155,7 +1241,7 @@ func (s *manifestStore) push(ctx context.Context, expected ocispec.Descriptor, c
 // and indexes referrers for the manifest when needed.
 func (s *manifestStore) pushWithIndexing(ctx context.Context, expected ocispec.Descriptor, r io.Reader, reference string) error {
 	switch expected.MediaType {
-	case ocispec.MediaTypeArtifactManifest, ocispec.MediaTypeImageManifest:
+	case spec.MediaTypeArtifactManifest, ocispec.MediaTypeImageManifest:
 		if state := s.repo.loadReferrersState(); state == referrersStateSupported {
 			// referrers API is available, no client-side indexing needed
 			return s.push(ctx, expected, r, reference)
@@ -1183,8 +1269,8 @@ func (s *manifestStore) pushWithIndexing(ctx context.Context, expected ocispec.D
 func (s *manifestStore) indexReferrersForPush(ctx context.Context, desc ocispec.Descriptor, manifestJSON []byte) error {
 	var subject ocispec.Descriptor
 	switch desc.MediaType {
-	case ocispec.MediaTypeArtifactManifest:
+	case spec.MediaTypeArtifactManifest:
-		var manifest ocispec.Artifact
+		var manifest spec.Artifact
 		if err := json.Unmarshal(manifestJSON, &manifest); err != nil {
 			return fmt.Errorf("failed to decode manifest: %s: %s: %w", desc.Digest, desc.MediaType, err)
 		}
@@ -1271,7 +1357,11 @@ func (s *manifestStore) updateReferrersIndex(ctx context.Context, subject ocispe
 		// 4. delete the dangling original referrers index
 		if !skipDelete {
 			if err := s.repo.delete(ctx, oldIndexDesc, true); err != nil {
-				return fmt.Errorf("failed to delete dangling referrers index %s for referrers tag %s: %w", oldIndexDesc.Digest.String(), referrersTag, err)
+				return &ReferrersError{
+					Op:      opDeleteReferrersIndex,
+					Err:     fmt.Errorf("failed to delete dangling referrers index %s for referrers tag %s: %w", oldIndexDesc.Digest.String(), referrersTag, err),
+					Subject: subject,
+				}
 			}
 		}
 		return nil

vendor/oras.land/oras-go/v2/registry/remote/url.go

@@ -20,6 +20,7 @@ import (
 	"net/url"
 	"strings"
 
+	"github.com/opencontainers/go-digest"
 	"oras.land/oras-go/v2/registry"
 )
 
@@ -87,6 +88,17 @@ func buildRepositoryBlobUploadURL(plainHTTP bool, ref registry.Reference) string
 	return buildRepositoryBaseURL(plainHTTP, ref) + "/blobs/uploads/"
 }
 
+// buildRepositoryBlobMountURLbuilds the URL for cross-repository mounting.
+// Format: <scheme>://<registry>/v2/<repository>/blobs/uploads/?mount=<digest>&from=<other_repository>
+// Reference: https://docs.docker.com/registry/spec/api/#blob
+func buildRepositoryBlobMountURL(plainHTTP bool, ref registry.Reference, d digest.Digest, fromRepo string) string {
+	return fmt.Sprintf("%s?mount=%s&from=%s",
+		buildRepositoryBlobUploadURL(plainHTTP, ref),
+		d,
+		fromRepo,
+	)
+}
+
 // buildReferrersURL builds the URL for querying the Referrers API.
 // Format: <scheme>://<registry>/v2/<repository>/referrers/<digest>?artifactType=<artifactType>
 // Reference: https://github.com/opencontainers/distribution-spec/blob/v1.1.0-rc1/spec.md#listing-referrers

vendor/oras.land/oras-go/v2/registry/repository.go

@@ -107,6 +107,19 @@ type TagLister interface {
 	Tags(ctx context.Context, last string, fn func(tags []string) error) error
 }
 
+// Mounter allows cross-repository blob mounts.
+// For backward compatibility reasons, this is not implemented by
+// BlobStore: use a type assertion to check availability.
+type Mounter interface {
+	// Mount makes the blob with the given descriptor in fromRepo
+	// available in the repository signified by the receiver.
+	Mount(ctx context.Context,
+		desc ocispec.Descriptor,
+		fromRepo string,
+		getContent func() (io.ReadCloser, error),
+	) error
+}
+
 // Tags lists the tags available in the repository.
 func Tags(ctx context.Context, repo TagLister) ([]string, error) {
 	var res []string