Tag: printers

I got something working recently, and I thought it was interesting enough that it’d be worth sharing.

Our MDM server is a SaaS instance of Workspace ONE UEM, and we have the AirWatch Cloud Connector installed in an on-prem VM to provide integration with Active Directory. Although WS1 bundles its own (modified) version of Munki, we don’t use it – we have a separate on-prem VM for our vanilla Munki server.

Unfortunately, this post is partially about printers (sorry). The challenge with setting up LPD printers on the macOS, is that the drivers need to be installed before the printer is added (or the printer is added with a generic driver, and must be removed and reinstalled). Munki is an excellent use case for this, as the requires and update_for pkginfo keys are perfect for setting up dependencies.

For several years, I used Graham Gilbert’s printer-pkginfo script to deploy printers with Munki. That, combined with my NoMAD group condition script, allowed me to deploy printers to only certain people’s devices – their user accounts in AD needed to be a member of a particular group.

With macOS 12.3 dropping Python 2 from the OS, I needed another solution. I landed on wyncomco’s fork of Nick McSpadden’s PrinterGenerator script. It works well, but with our move from NoMAD to Jamf Connect, how would we be able to leverage our AD groups to deploy these printers?

Thanks to the AirWatch Cloud Connector, I was able to add the AD security group to WS1 (in Accounts > User Groups > List View). The group in WS1 syncs periodically with AD, so users added to AD will appear in the WS1 group after a few hours.

In my case, though, I needed a Smart Group (sometimes called an “Assignment Group”) to actually make use of the user group. In Groups & Settings > Groups > Assignment Groups, add a new Smart Group where the first criteria is the Organization Group that contains your devices. Scroll down to User Group, and select the group you’re synching from AD. Name your Smart Group and click Save.

The last piece was how I’d get the printer to these users. Around the same time, VMware added the ability to run scripts through Workspace ONE. I had remembered Nick McSpadden’s post about Local-Only Manifests in Munki, which was perfect for this. I’d set up a separate manifest for WS1 to write to, and Munki would install the printer driver and the printer automatically.

First, in your Munki configuration profile, add this:

<key>LocalOnlyManifest</key>
<string>LocalOnlyManifest.plist</string>

This tells Munki to check this additional manifest for potential items to install. There’s no need to create the file – if it doesn’t exist, Munki proceeds as normal, without printing any warnings/errors.

Lastly, add this script to WS1 (in Resources > Scripts), and assign it to your Smart Group. Set the language to Bash, and the execution context to System.

#!/bin/bash

defaults="/usr/bin/defaults"
grep="/usr/bin/grep"

printer_installed=$(${defaults} read "/Library/Managed Installs/manifests/LocalOnlyManifest" managed_installs | ${grep} "MyPrinter")

if [ ! "${printer_installed}" ]; then
 ${defaults} write "/Library/Managed Installs/manifests/LocalOnlyManifest" managed_installs -array-add "MyPrinter"
else
    exit 0
fi

exit

In my case, I have it run immediately upon device enrollment, as well as when the network interface changes. The code runs a check to see if the Munki item MyPrinter is in the LocalOnlyManifest, and if not, it adds it. The next time Munki runs a background check, it will install the driver and printer automatically.

The end result is that when a user requires our printer, any AD admin can add the user to a particular group. Some time later, the user will receive the printer without needing to do anything. If the user already has our printer, but receives a new computer, the printer will be added as soon as the computer is set up – no additional admin work necessary.

I hope someone finds this useful for more than just printers!