attempt

Signed-off-by: Xiaoxuan Wang <[email protected]>

cmd/oras/internal/option/spec.go

@@ -27,6 +27,7 @@ import (
 const (
 	ImageSpecV1_1 = "v1.1"
 	ImageSpecV1_0 = "v1.0"
+	ImageSpecAuto = "auto"
 )
 
 const (
@@ -36,15 +37,15 @@ const (
 
 // ImageSpec option struct which implements pflag.Value interface.
 type ImageSpec struct {
-	flag        string
+	Flag        string
 	PackVersion oras.PackManifestVersion
 }
 
 // Set validates and sets the flag value from a string argument.
 func (is *ImageSpec) Set(value string) error {
-	is.flag = value
+	is.Flag = value
 	switch value {
-	case ImageSpecV1_1:
+	case ImageSpecV1_1, ImageSpecAuto:
 		is.PackVersion = oras.PackManifestVersion1_1
 	case ImageSpecV1_0:
 		is.PackVersion = oras.PackManifestVersion1_0
@@ -67,19 +68,20 @@ func (is *ImageSpec) Options() string {
 	return strings.Join([]string{
 		ImageSpecV1_1,
 		ImageSpecV1_0,
+		ImageSpecAuto,
 	}, ", ")
 }
 
 // String returns the string representation of the flag.
 func (is *ImageSpec) String() string {
-	return is.flag
+	return is.Flag
 }
 
 // ApplyFlags applies flags to a command flag set.
 func (is *ImageSpec) ApplyFlags(fs *pflag.FlagSet) {
-	// default to v1.1-rc.4
+	// default to auto
 	is.PackVersion = oras.PackManifestVersion1_1
-	defaultFlag := ImageSpecV1_1
+	defaultFlag := ImageSpecAuto
 	fs.Var(is, "image-spec", fmt.Sprintf(`[Experimental] specify manifest type for building artifact. Options: %s (default %q)`, is.Options(), defaultFlag))
 }
 

cmd/oras/root/push.go

@@ -109,12 +109,13 @@ Example - Push file "hi.txt" into an OCI image layout folder 'layout-dir' with t
 				return err
 			}
 
-			// if --config is not used, image spec version is automatically set
-			// to 1.0; otherwise the version is set to 1.1.
-			if opts.manifestConfigRef == "" {
-				opts.PackVersion = oras.PackManifestVersion1_0
-			} else {
-				opts.PackVersion = oras.PackManifestVersion1_1
+			if opts.manifestConfigRef != "" && opts.artifactType == "" {
+				switch opts.Flag {
+				case option.ImageSpecAuto:
+					opts.PackVersion = oras.PackManifestVersion1_0
+				case option.ImageSpecV1_1:
+					return errors.New("--artifact-type must be set for 1.1 OCI image")
+				}
 			}
 
 			switch opts.PackVersion {
@@ -125,8 +126,6 @@ Example - Push file "hi.txt" into an OCI image layout folder 'layout-dir' with t
 			case oras.PackManifestVersion1_1:
 				if opts.manifestConfigRef == "" && opts.artifactType == "" {
 					opts.artifactType = oras.MediaTypeUnknownArtifact
-				} else if opts.artifactType == "" {
-					return errors.New("--artifact-type must be set for 1.1 OCI image")
 				}
 			}
 			return nil