
##### SUMMARY

RDS services can auto-allocate storage. So you can start with the lowest ebs volume and don't care anymore about growing data in der database.  
The boto3 parameter to activate this feature is `MaxAllocatedStorage` (integer) 

>  The upper limit to which Amazon RDS can automatically scale the storage of the DB instance.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
rds_instance


state = module.params['state']
    skip_final_snapshot = module.params['skip_final_snapshot']
    snapshot_id = module.params['final_db_snapshot_identifier']
    modified_id = module.params['new_db_instance_identifier']
    engine = module.params['engine']
    tde_options = bool(module.params['tde_credential_password'] or module.params['tde_credential_arn'])
    read_replica = module.params['read_replica']
    creation_source = module.params['creation_source']
    source_instance = module.params['source_db_instance_identifier']
    if module.params['source_region'] is not None:
        same_region = bool(module.params['source_region'] == module.params['region'])
    else:
        same_region = True
    if modified_id:
        modified_instance = get_instance(client, module, modified_id)
    else:
        modified_instance = {}
    if modified_id and instance and modified_instance:
        module.fail_json(msg='A new instance ID {0} was provided but it already exists'.format(modified_id))
    if modified_id and not instance and modified_instance:
        module.fail_json(msg='A new instance ID {0} was provided but the instance to be renamed does not exist'.format(modified_id))
    if state in ('absent', 'terminated') and instance and not skip_final_snapshot and snapshot_id is None:
        module.fail_json(msg='skip_final_snapshot is false but all of the following are missing: final_db_snapshot_identifier')
    if engine is not None and not (engine.startswith('mysql') or engine.startswith('oracle')) and tde_options:
        module.fail_json(msg='TDE is available for MySQL and Oracle DB instances')
    if read_replica is True and not instance and creation_source not in [None, 'instance']:
        module.fail_json(msg='Cannot create a read replica from {0}. You must use a source DB instance'.format(creation_source))
    if read_replica is True and not instance and not source_instance:
        module.fail_json(msg='read_replica is true and the instance does not exist yet but all of the following are missing: source_db_instance_identifier')
def update_instance(client, module, instance, instance_id):