AutoDMG and High Sierra monolithic image?

[MKnight]

Hi all...we have been attempting to create a monolithic image of our new iMac Pro that came with High Sierra installed but are having no luck. I used the script here https://www.jamf.com/jamf-nation/discussions/27001/high-sierra-imaging-how-to to obtain the firmware package and then added that as a package component in AutoDMG, then dragged the high Sierra installer.app from the applications folder into AutoDMG to create the new image which I copied to an external USB. I then booted into internet recovery > launched Disk Utility and clicked on the APFS container and selected restore from my external USB. The imaging goes through but the computer will not boot, it gets stuck displaying a folder icon instead. What am I doing wrong here? I see that AutoDMG supports High Sierra so I am not why it is not working.
Should I create my image using Disk Utility instead of AutoDMG? or is there another recommended way of creating a High Sierra image?

[SDamianoINWK]

I honestly don't know much about Imaging and High Sierra, but I would be curious to know what state your iMac is in after imaging. Are you able to do a normal restore on it, or does it need to do a DFU restore via Apple Configurator? That is a recent change to the iMac Pro that in some cases, restore requires the iMac Pro to be in DFU and connected to another computer via Apple Configurator, due to the T2 coprocessor.

[RobertHammen]

Boy oh boy. Let me send you to this website...

iMac Pro has secure boot. I don't see any way you're going to get this working.

Better option, explore the 10.13.4 Install macOS High Sierra.app's version of startosinstall. Particularly, the --eraseinstall option.

"In the 10.13.4 installer, startosinstall gets a new --eraseinstall option. You must be using the 10.13.4 installer and using an APFS disk. Creates a temp partition, copies the installation assets to it and restarts, and erases the primary volume. This allows for automated workflows where you can wipe and re-install macOS, add a few custom packages to the installation process with --installpackage arguments, which configure your management system. Then after first boot your management system takes over and installs/configures the rest.

It is important to note that startosinstall uses some APFS volume creation trickery to make --eraseinstall work. This means that you cannot run --eraseinstall on a Mac with a HFS+ system volume. You have to already be on a 10.13 system with APFS to use this option."

[hkabik]

I'm getting the same issue using Jamf Imaging with a 10.13.4 image made from autodmg on all Machines MBP, MBA, etc. DEP is fine for the machines we've purchased but I need to be able to image machines we acquire through company acquisition. At the moment, I cannot with the latest OS. :/

[bradtchapman]

Hey @MKnight and others...

The iMac Pro comes with Full Security enabled right out of the box. Full Security requires that the operating system and all software updates are signed / sealed / blessed by Apple at the time of installation. Your AutoDMG disk certainly would not be recognized. As far as I can tell, this setting can only be changed from recovery mode after a user account has been created on the system.

I tried to work around it, but no such luck. Launching the "Startup Security Utility" from Recovery Mode will prompt for the password of some local administrator. If none exists, the utility will not load.