Avoiding Munki install loops

One of the most frequent questions that comes up with new Munki admins is Munki successfully installed some software, but now each time Munki runs, it wants to install the software again. Why is this?

You will know exactly why an install loop happens (and how to fix it) if you read How Munki Decides What Needs To Be Installed

You’ve read both of those links, right?

If you use Munki to “install” a drag-and-drop .app bundle in a .dmg, you’re very unlikely to run into an install loop.

The two things you’re most likely to run into install loops with are .pkgs vendors badly package or nopkgs that you yourself create where the postinstall_script doesn’t change things to satisfy the installcheck_script.

Then, of course, you can also run into install loops if you accidentally make an OnDemand item a managed install (instead of an optional install).

While it’s entirely possible your school is using badly packaged .pkgs that no one else is using, chances are someone else has already dealt with the install loop item you’re dealing with, so definitely check to see if there’s an AutoPkg recipe for the item (the recipe maintainer will most likely have the .munki recipe create an installs array to prevent install loops). You can also check the Munki wiki for procedures for various special cases (for example, FileMaker Pro, Logger Pro, Adobe CC, Symantec Endpoint Protection).

If you can’t find an AutoPkg recipe or a Munki wiki page about a particular weird package, you can try just Googling for name of software Munki, and you might come across a handy blog entry about it. If you still can’t figure it out, don’t be afraid to ask for help on the #munki channel on the MacAdmins Slack or on the Munki Discuss mailing list.

Note: In 2025, I gave a talk at MacDevOpsYVR about avoiding Munki install loops.