feat: support nydus image format

internal/image/oci.go

@@ -292,6 +292,8 @@ func (m *manifestOCI1) convertToManifestSchema2(_ context.Context, options *type
 		case ociencspec.MediaTypeLayerEnc, ociencspec.MediaTypeLayerGzipEnc, ociencspec.MediaTypeLayerZstdEnc,
 			ociencspec.MediaTypeLayerNonDistributableEnc, ociencspec.MediaTypeLayerNonDistributableGzipEnc, ociencspec.MediaTypeLayerNonDistributableZstdEnc:
 			return nil, fmt.Errorf("during manifest conversion: encrypted layers (%q) are not supported in docker images", layers[idx].MediaType)
+		case manifest.NydusBootstrapLayerMediaType, manifest.NydusBlobLayerMediaType:
+			layers[idx].MediaType = manifest.DockerV2Schema2ForeignLayerMediaType
 		default:
 			return nil, fmt.Errorf("Unknown media type during manifest conversion: %q", layers[idx].MediaType)
 		}

internal/manifest/manifest.go

@@ -32,6 +32,10 @@ const (
 	DockerV2Schema2ForeignLayerMediaType = "application/vnd.docker.image.rootfs.foreign.diff.tar"
 	// DockerV2Schema2ForeignLayerMediaType is the MIME type used for gzipped schema 2 foreign layers.
 	DockerV2Schema2ForeignLayerMediaTypeGzip = "application/vnd.docker.image.rootfs.foreign.diff.tar.gzip"
+	// NydusBootstrapLayerMediaType is the MIME type used for Nydus bootstrap layers.
+	NydusBootstrapLayerMediaType = "application/vnd.containers.image.nydus.bootstrap.v1+json"
+	// NydusBlobLayerMediaType is the MIME type used for Nydus data blob layers.
+	NydusBlobLayerMediaType = "application/vnd.containers.image.nydus.blob.v1"
 )
 
 // GuessMIMEType guesses MIME type of a manifest and returns it _if it is recognized_, or "" if unknown or unrecognized.

manifest/manifest.go

@@ -32,6 +32,10 @@ const (
 	DockerV2Schema2ForeignLayerMediaType = manifest.DockerV2Schema2ForeignLayerMediaType
 	// DockerV2Schema2ForeignLayerMediaType is the MIME type used for gzipped schema 2 foreign layers.
 	DockerV2Schema2ForeignLayerMediaTypeGzip = manifest.DockerV2Schema2ForeignLayerMediaTypeGzip
+	// NydusBootstrapLayerMediaType is the MIME type used for Nydus bootstrap layers.
+	NydusBootstrapLayerMediaType = manifest.NydusBootstrapLayerMediaType
+	// NydusBlobLayerMediaType is the MIME type used for Nydus data blob layers.
+	NydusBlobLayerMediaType = manifest.NydusBlobLayerMediaType
 )
 
 // NonImageArtifactError (detected via errors.As) is used when asking for an image-specific operation

manifest/oci.go

@@ -47,7 +47,8 @@ func SupportedOCI1MediaType(m string) error {
 		imgspecv1.MediaTypeImageLayerNonDistributable, imgspecv1.MediaTypeImageLayerNonDistributableGzip, imgspecv1.MediaTypeImageLayerNonDistributableZstd, //nolint:staticcheck // NonDistributable layers are deprecated, but we want to continue to support manipulating pre-existing images.
 		imgspecv1.MediaTypeImageManifest,
 		imgspecv1.MediaTypeLayoutHeader,
-		ociencspec.MediaTypeLayerEnc, ociencspec.MediaTypeLayerGzipEnc:
+		ociencspec.MediaTypeLayerEnc, ociencspec.MediaTypeLayerGzipEnc,
+		manifest.NydusBootstrapLayerMediaType, manifest.NydusBlobLayerMediaType:
 		return nil
 	default:
 		return fmt.Errorf("unsupported OCIv1 media type: %q", m)
@@ -142,9 +143,18 @@ func (m *OCI1) UpdateLayerInfos(layerInfos []types.BlobInfo) error {
 			}
 			mimeType = decMimeType
 		}
-		mimeType, err := updatedMIMEType(oci1CompressionMIMETypeSets, mimeType, info)
-		if err != nil {
-			return fmt.Errorf("preparing updated manifest, layer %q: %w", info.Digest, err)
+		// Nydus layer types don't support compression/decompression operations
+		// They should only be preserved as-is
+		if mimeType == manifest.NydusBootstrapLayerMediaType || mimeType == manifest.NydusBlobLayerMediaType {
+			if info.CompressionOperation != types.PreserveOriginal {
+				return fmt.Errorf("preparing updated manifest, layer %q: Nydus layer types (%q) do not support compression or decompression operations", info.Digest, mimeType)
+			}
+		} else {
+			var err error
+			mimeType, err = updatedMIMEType(oci1CompressionMIMETypeSets, mimeType, info)
+			if err != nil {
+				return fmt.Errorf("preparing updated manifest, layer %q: %w", info.Digest, err)
+			}
 		}
 		if info.CryptoOperation == types.Encrypt {
 			encMediaType, err := getEncryptedMediaType(mimeType)