Change config media type

Signed-off-by: Shiwei Zhang <shizh@microsoft.com>

pkg/registry/client.go

@@ -97,7 +97,8 @@ func (c *Client) PushChart(ref *Reference) error {
 	if err != nil {
 		return err
 	}
-	_, err = oras.Push(c.newContext(), c.resolver, ref.String(), c.cache.store, layers)
+	pushOpt := oras.WithConfig(c.cache.store.Add("", HelmChartConfigMediaType, []byte("{}")))
+	_, err = oras.Push(c.newContext(), c.resolver, ref.String(), c.cache.store, layers, pushOpt)
 	if err != nil {
 		return err
 	}

pkg/registry/constants.go

@@ -20,6 +20,9 @@ const (
 	// HelmChartDefaultTag is the default tag used when storing a chart reference with no tag
 	HelmChartDefaultTag = "latest"
 
+	// HelmChartConfigMediaType is the reserved media type for Helm chart config
+	HelmChartConfigMediaType = "application/vnd.cncf.helm.config.v1+json"
+
 	// HelmChartMetaMediaType is the reserved media type for Helm chart metadata
 	HelmChartMetaMediaType = "application/vnd.cncf.helm.chart.meta.v1+json"