Returns a list of resources (for example, DB instances) that have atleast one pending maintenance action.Show details from next link. https://docs.aws.amazon.com/ja_jp/cli/latest/reference/rds/describe-pending-maintenance-actions.html
| aws rds describe-pending-maintenance-actions \ |
| RDS OS update | the gabriellephant : http://gorthx.wordpress.com/2016/02/03/rds-os-update/ |