portainer/app/directives/widget-footer.js

angular
.module('uifordocker')
.directive('rdWidgetFooter', function rdWidgetFooter() {
  var directive = {
    requires: '^rdWidget',
    transclude: true,
    template: '<div class="widget-footer" ng-transclude></div>',
    restrict: 'E'
  };
  return directive;
});