- `sources` ([]string) - A list of sources to upload. This can be used in place of the `source` option if you have several files that you want to upload to the same place. Note that the destination must be a directory with a trailing slash, and that all files listed in `sources` will be uploaded to the same directory with their file names preserved. - `direction` (string) - The direction of the file transfer. This defaults to "upload". If it is set to "download" then the file "source" in the machine will be downloaded locally to "destination" - `generated` (bool) - For advanced users only. If true, check the file existence only before uploading, rather than upon pre-build validation. This allows users to upload files created on-the-fly. This defaults to false. We don't recommend using this feature, since it can cause Packer to become dependent on system state. We would prefer you generate your files before the Packer run, but realize that there are situations where this may be unavoidable.