Comment 1 for bug 1770343

The CLI options are optional because if not specified the values are pulled from the config file, which you can provide via the --config-file option, and so you don't have to write URLs with credentials into scripts. The fact it fails with "The specified transport_url and/or database_connection combination already exists for another cell with uuid" is because you're trying to create a cell using the same config as another cell that already exists, so I'm not sure that this is a bug.