Plugins: Fix manifest verification (#24573)

pkg/plugins/backendplugin/client.go

@@ -55,7 +55,7 @@ type PluginStartFuncs struct {
 	OnStart       StartFunc
 }
 
-// PluginDescriptor descriptor used for registering backend plugins.
+// PluginDescriptor is a descriptor used for registering backend plugins.
 type PluginDescriptor struct {
 	pluginID         string
 	executablePath   string
@@ -64,6 +64,11 @@ type PluginDescriptor struct {
 	startFns         PluginStartFuncs
 }
 
+// PluginID returns the plugin ID.
+func (pd PluginDescriptor) PluginID() string {
+	return pd.pluginID
+}
+
 // getV2PluginSet returns list of plugins supported on v2.
 func getV2PluginSet() goplugin.PluginSet {
 	return goplugin.PluginSet{