Introducing Installomator

As a System Engineer at an Enterprise Reseller, I have to manage and create many Jamf Pro instances.

Some of them are tightly managed and require version control on the OS and the apps. But, many of them are managed less stringently and often the requirement for applications is “install the latest version.”

This is not a statement which management strategy is ‘better.’ There are pros and cons for each. There are situations where either is really not appropriate. You will likely have to use a mixed approach for different pieces of software. When you are doing the first, more controlled deployment strategy, you really want to use AutoPkg and not this script. You can stop reading here.

Apple’s vision of deployment with ‘Automated App Installation’ through MDM (formerly known as VPP) is similar to the ‘less controlled’ strategy. When you install Mac App Store through MDM commands, then you will get the latest version available.

Not all applications are available on the Mac App Store. And even when they are available, installing applications with VPP is still unreliable and hard to debug, or retry when it fails.

If you are managing with the “just install the latest version” philosophy, then you probably have one or more scripts that will download and install the latest version of some software from the vendor’s website. This avoids the overhead work of having to download, repackage and manage every new update in the management system. (This can be automated with AutoPkg, but if you can avoid it entirely…)

When I started thinking about this, we had at least four different scripts. Most of them were internal, but William Smith’s installer script for Microsoft applications was a huge inspiration. it made me thing that you could generalize much of this.

Security Considerations

The main danger when downloading application archives and installers directly from the vendor is that a malicious actor might intercept the traffic or even hijack the servers and replace the download with a manipulated software that contains and or installs malware. Since management processes run with root privileges, we have to extra careful which files and processes are installed.

For user driven installation, Apple introduced GateKeeper, signed applications and Notarization as a way to verify downloaded software before execution. When you download software with a script, then you are bypassing GateKeeper. This is usually considered a benefit, because in a managed deployment we don’t want to scare and annoy a user with the warning dialogs.

But we can use the GateKeeper verification process in our script to verify that the archive, application, or installer is signed and notarized. With the spctl command, we can run the verification from the script without the user interaction.

We can even go one step further than GateKeeper. GateKeeper is happy when a software is signed and notarized with any Apple Developer ID. Since this script is working with a curated list of software, we can verify that the application is actually signed with the expected vendor’s Developer ID.

This will catch situations where someone creates or steals a Developer ID to sign and notarize a manipulated application. Apple can and will eventually block that Developer ID, but there will be a window where the manipulated application may be downloaded and installed. This is not theoretical, but has happened already. (more than once)

Installomator

With these ideas in mind, I started working on a script to unify all these installer scripts. (‘The one to rule them all.’) I may have gone a little overboard, but it turned into Installomator.

You can run Installomator from the command line or from your management system.

> ./Installomator.sh desktoppr

The script requires a single argument. The argument is a label that chooses which application to download and install. (As of now, Installomator can handle 56 applications, you can see a list of applications in the repository.

Please read the readme in the GitHub repository for more details.

Jamf or not

I have tried to keep Installomator generic enough that it can be used with platforms other than Jamf Pro.

However, we will use it with Jamf Pro, and thus I took the opportunity to add some workflows that Jamf is missing.

Drag’n Drop installations

“Drag this app to the Applications folder” is a common instruction found on downloaded dmg or zip archives for the Mac. The fact that Jamf Pro has always required repackaging and cannot directly handle application dmgs or zips is mystifying. Also, highly ironic, since Jamf delivers their own management applications in a disk image.

Nevertheless, Installomator can deal with apps that are downloaded in zip, tbz, and dmg archives.

Blocking Processes

Jamf will also happily attempt to install over a running application. So, Installomator will check for blocking processes and either stop the installation at that time or prompt the user and give them a chance to quit the application. (Yes, this is inspired by the behavior of Munki.)

Vendor update processes

Since Installomator will download and install the latest version of the application from the vendor website, it can be used for updates as well as first installations.

If an application has a built-in update process that can be triggered by the script, This can be used instead for updates. So, for Microsoft applications, when the script detects that the app is already installed, it will run msupdate instead of downloading a full installer. This way the update process will use Microsoft’s optimized thin updates. (Credit to Isaac Ordonez, Mann consulting for the idea and first implementation.)

So far, this is only implemented for Microsoft applications and Google Chrome. (and quite experimental)

Extensible

So far, the script can install 56 different applications or application suites. More application descriptions can be added fairly easily, by adding the proper variables. You can find more detailed explanations in the ReadMe, and of course, the existing applications serve as examples.

Not all applications are suitable to be installed with Installomator. To be able to install an application, the download URL must be accessible without requiring a login, and there must be some, fairly simple process to determine the URL for the latest version.

Installomator will only install the application itself, it will not configure any settings. You will have to use profiles, or additional scripts and installers for that.

When you add an application for your own workflow, please contribute as an issue or pull request! Thank you!

Installomator and AutoPkg

Obviously, much of Installomator’s workflow has been heavily inspired by AutoPkg. I have been using AutoPkg for a long time and provide a repository of recipes. And I plan to continue to use AutoPkg.

As mentioned before, Installomator is not suitable for every type of deployment. If you require control over the versions of the software deployed, then you need to download, re-package and manage the packages in your management system. This is obviously what AutoPkg was designed for.

Also, not every software can be installed with Installomator, mostly because the installer is not available as a direct download. In these cases, AutoPkg will be useful to automate the management and deployment, even when you management style is less controlling.

Going Forward

We have been using Installomator for the past few weeks in our own deployment and with one customer. We are now at a point, where we believe it is stable enough to share it and get feedback from other MacAdmins. (I have already shared it with a few, and many thanks to those that have given valuable feedback.)

We have been using this script with two smaller deployments and want to roll it out to more of our customers. But we probably haven’t hit all the weird edge cases yet. So, proceed with caution.

Consider this a beta release.

(Sidenote: I have tested the script with 10.14.6 and 10.15.x. Because it uses the notarization verification which is available in 10.14.4 and higher it will probably not run well on older macOS versions. Might be possible to adapt it though.)

If you are as excited about the script as we are, please start testing in your environment and provide feedback. But please, as with anything MacAdmin, don’t just go and push the script to hundreds or thousands of devices, but test, test, test first.

Then please provide any enhancements back on the GitHub repository. I have also created an #installomator channel on the MacAdmin Slack for discussion and questions.

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