remotes: use mediatype helpers

Signed-off-by: Bjorn Neergaard <bjorn.neergaard@docker.com>

remotes/docker/converter.go

@@ -41,9 +41,7 @@ const LegacyConfigMediaType = "application/octet-stream"
 // 1. original manifest will be deleted by next gc round.
 // 2. don't cover manifest list.
 func ConvertManifest(ctx context.Context, store content.Store, desc ocispec.Descriptor) (ocispec.Descriptor, error) {
-	if !(desc.MediaType == images.MediaTypeDockerSchema2Manifest ||
-		desc.MediaType == ocispec.MediaTypeImageManifest) {
-
+	if !images.IsManifestType(desc.MediaType) {
 		log.G(ctx).Warnf("do nothing for media type: %s", desc.MediaType)
 		return desc, nil
 	}

remotes/docker/fetcher.go

@@ -94,10 +94,8 @@ func (r dockerFetcher) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.R
 		}
 
 		// Try manifests endpoints for manifests types
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, images.MediaTypeDockerSchema2ManifestList,
-			images.MediaTypeDockerSchema1Manifest,
-			ocispec.MediaTypeImageManifest, ocispec.MediaTypeImageIndex:
+		if images.IsManifestType(desc.MediaType) || images.IsIndexType(desc.MediaType) ||
+			desc.MediaType == images.MediaTypeDockerSchema1Manifest {
 
 			var firstErr error
 			for _, host := range r.hosts {

remotes/docker/pusher.go

@@ -103,12 +103,10 @@ func (p dockerPusher) push(ctx context.Context, desc ocispec.Descriptor, ref str
 		host       = hosts[0]
 	)
 
-	switch desc.MediaType {
-	case images.MediaTypeDockerSchema2Manifest, images.MediaTypeDockerSchema2ManifestList,
-		ocispec.MediaTypeImageManifest, ocispec.MediaTypeImageIndex:
+	if images.IsManifestType(desc.MediaType) || images.IsIndexType(desc.MediaType) {
 		isManifest = true
 		existCheck = getManifestPath(p.object, desc.Digest)
-	default:
+	} else {
 		existCheck = []string{"blobs", desc.Digest.String()}
 	}