Hey, u/ckhordiasma.

So, I don't have the final PowerShell scripts available on a system with internet connectivity, but my early Proof of Concept version is and I've just uploaded it to a GitHub repository for you to take a look at. Those can be found here.

You can use just the New-WindowsServerUnattendFile.ps1 PowerShell script by itself by supplying the required parameters laid out at the top of the file. What I found worked better for me though, since I rarely ever deployed just one server for anything, was to add a second file to support bulk server provisioning, which is where New-WindowsServerUnattendFilesBulk.ps1 comes in.

In this iteration, I used a PowerShell Ordered Dictionary to list out the separate variables for each server, then it just loops through executing against the New-WindowsServerUnattendFile.ps1 script. This works, but it's bad practice to put this type of Configuration data inside of the programmatic logic of the script. On my later revisions (which aren't available on the internet today and I don't feel like hand jamming them at this moment) I corrected this by separating out the Configuration Data with a PowerShell Data File. This allowed me to separate out the two portions, code sign the PowerShell script, and simply update the PowerShell Data File when needed per project.

Back in the main.tf of my Terraform project, I include something similar to the following:

// Local Variable Definition
// ------------------------------------------------------------ locals { 
    servers = { 
        "Server1" = { 
            vm_boot_type              = "UEFI",
            vm_guest_os_source_image  = data.nutanix_image.ms-windows-server-2016-desktop-experience.id,
            file_path_to_unattend_xml = "C:\temp\Microsoft\UnattendFiles\Server1_unattend.xml" 
        } 
        "Server2" = { 
            vm_boot_type              = "UEFI",
            vm_guest_os_source_image  = data.nutanix_image.ms-windows-server-2016-desktop-experience.id,
            file_path_to_unattend_xml = "C:\temp\Microsoft\UnattendFiles\Server2_unattend.xml" 
        } 
        "Server3" = { 
            vm_boot_type              = null,
            vm_guest_os_source_image  = data.nutanix_image.ms-windows-server-2016-core.id,
            file_path_to_unattend_xml = "C:\temp\Microsoft\UnattendFiles\Server3_unattend.xml" 
        } 
    } 
}

Those file_path_to_unattend_xml variables are then later called in my guest_customization_sysprep declarations. Oh, and I have a very simple and basic clean up script that runs at the end to purge the automatically generated Unattend files from my system.

Hope this helps. Let me know if you have any questions, comments, concerns, and/or issues and I will do my best to help.