How to override default root URL of plugin? how can I override default root URL behavior via routes? I did following but not working:

'pluginname/' =&gt; array('action' =&gt; 'pluginName/Controller/actionName');


my template file name is index
This works for me:

public function registerCpRoutes()
{
    return array(
        'settings/plugins/pluginname/index' =&gt; 'pluginname/index'
    );
}