Merge pull request #3510 from tonistiigi/fix-mediatype-concurrency

imagetools: fix concurrent map write from containerd issue

Author: jsternberg

commands/imagetools/create.go

@@ -168,11 +168,6 @@ func runCreate(ctx context.Context, dockerCli command.Cli, in createOptions, arg
 		return errors.Wrapf(err, "failed to parse annotations")
 	}
 
-	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.oci.empty.v1+json", "empty")
-	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.artifact.sig.v1+json", "cosign")
-	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.simplesigning.v1+json", "simplesigning")
-	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.sigstore.bundle.v0.3+json", "sigstore-bundle")
-
 	dt, desc, manifests, err := r.Combine(ctx, srcs, annotations, in.preferIndex, platforms)
 	if err != nil {
 		return err
@@ -208,16 +203,19 @@ func runCreate(ctx context.Context, dockerCli command.Cli, in createOptions, arg
 	for _, t := range tags {
 		eg.Go(func() error {
 			return progress.Wrap(fmt.Sprintf("pushing %s", t.String()), pw.Write, func(sub progress.SubLogger) error {
+				baseCtx := ctx
 				eg2, _ := errgroup.WithContext(ctx)
 				for _, desc := range manifests {
 					eg2.Go(func() error {
+						ctx = withMediaTypeKeyPrefix(baseCtx)
 						sub.Log(1, fmt.Appendf(nil, "copying %s from %s to %s\n", desc.Digest.String(), desc.Source.Ref.String(), t.String()))
 						return r.Copy(ctx, desc.Source, t)
 					})
 				}
 				if err := eg2.Wait(); err != nil {
 					return err
 				}
+				ctx = withMediaTypeKeyPrefix(ctx) // because of containerd bug this needs to be called separately for each ctx/goroutine pair to avoid concurrent map write
 				sub.Log(1, fmt.Appendf(nil, "pushing %s to %s\n", desc.Digest.String(), t.String()))
 				return r.Push(ctx, t, desc, dt)
 			})
@@ -265,6 +263,14 @@ func parsePlatforms(in []string) ([]ocispecs.Platform, error) {
 	return out, nil
 }
 
+func withMediaTypeKeyPrefix(ctx context.Context) context.Context {
+	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.oci.empty.v1+json", "empty")
+	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.artifact.sig.v1+json", "cosign")
+	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.cosign.simplesigning.v1+json", "simplesigning")
+	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.dev.sigstore.bundle.v0.3+json", "sigstore-bundle")
+	return ctx
+}
+
 func parseRefs(in []string) ([]reference.Named, error) {
 	refs := make([]reference.Named, len(in))
 	for i, in := range in {