Validator: add file-exists as replacement to Vyatta check_file_in_config_dir
Validator: add file-exists as replacement to Vyatta check_file_in_config_dir

Verify if a file exists or not on the system. Can be called by:
<constraint>
  <validator name="file-exists" argument="--directory /config/auth"/>
</constraint>

The --directory option is used to ensure a given file path lies under this
(mandatory) directory. A directory can be mandatory when the optional argument
-e, --error is used. This will return '1' instead of '0'.

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x