feat: use --artifact-type to change the media type of the config blob (…

…#482)

Signed-off-by: Haoliang Yue <yuehaoliang@microsoft.com>

cmd/oras/push.go

@@ -17,6 +17,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -40,6 +41,7 @@ type pushOptions struct {
 
 	targetRef         string
 	manifestConfigRef string
+	artifactType      string
 }
 
 func pushCmd() *cobra.Command {
@@ -58,6 +60,9 @@ Example - Push file "hi.txt" with the custom "application/vnd.me.hi" media type:
 Example - Push multiple files with different media types:
   oras push localhost:5000/hello:latest hi.txt:application/vnd.me.hi bye.txt:application/vnd.me.bye
 
+Example - Push file "hi.txt" with "application/vnd.me.config" as config type:
+  oras push --artifact-type application/vnd.me.config localhost:5000/hello:latest hi.txt
+
 Example - Push file "hi.txt" with the custom manifest config "config.json" of the custom "application/vnd.me.config" media type:
   oras push --manifest-config config.json:application/vnd.me.config localhost:5000/hello:latest hi.txt
 
@@ -69,6 +74,9 @@ Example - Push file to the HTTP registry:
 `,
 		Args: cobra.MinimumNArgs(1),
 		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if opts.artifactType != "" && opts.manifestConfigRef != "" {
+				return errors.New("--artifact-type and --manifest-config cannot both be provided")
+			}
 			return opts.ReadPassword()
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -79,6 +87,7 @@ Example - Push file to the HTTP registry:
 	}
 
 	cmd.Flags().StringVarP(&opts.manifestConfigRef, "manifest-config", "", "", "manifest config file")
+	cmd.Flags().StringVarP(&opts.artifactType, "artifact-type", "", "", "media type of config or manifest")
 
 	option.ApplyFlags(&opts, cmd.Flags())
 	return cmd
@@ -132,6 +141,9 @@ func packManifest(ctx context.Context, store *file.Store, annotations map[string
 	packOpts.ConfigAnnotations = annotations[annotationConfig]
 	packOpts.ManifestAnnotations = annotations[annotationManifest]
 
+	if opts.artifactType != "" {
+		packOpts.ConfigMediaType = opts.artifactType
+	}
 	if opts.manifestConfigRef != "" {
 		path, mediatype := parseFileReference(opts.manifestConfigRef, oras.MediaTypeUnknownConfig)
 		desc, err := store.Add(ctx, annotationConfig, mediatype, path)