- `format` (string) - Either ovf or ova, this specifies the output format of the exported virtual machine. This defaults to ovf. - `export_opts` ([]string) - Additional options to pass to the [VBoxManage export](https://www.virtualbox.org/manual/ch09.html#vboxmanage-export). This can be useful for passing product information to include in the resulting appliance file. Packer JSON configuration file example: In JSON: ```json { "type": "virtualbox-iso", "export_opts": [ "--manifest", "--vsys", "0", "--description", "{{user `vm_description`}}", "--version", "{{user `vm_version`}}" ], "format": "ova", } ``` In HCL2: ```hcl source "virtualbox-iso" "basic-example" { export_opts = [ "--manifest", "--vsys", "0", "--description", "{{user `vm_description`}}", "--version", "{{user `vm_version`}}" ] format = "ova" } ``` A VirtualBox [VM description](https://www.virtualbox.org/manual/ch09.html#vboxmanage-export-ovf) may contain arbitrary strings; the GUI interprets HTML formatting. However, the JSON format does not allow arbitrary newlines within a value. Add a multi-line description by preparing the string in the shell before the packer call like this (shell `>` continuation character snipped for easier copy & paste): ```shell vm_description='some multiline description' vm_version='0.2.0' packer build \ -var "vm_description=${vm_description}" \ -var "vm_version=${vm_version}" \ "packer_conf.json" ```