A customer pointed out to us that when a new version of TeamViewer was pushed to a client managed by Jamf Pro, the application would open during the installation of the package. That can be confusing to users, or badly timed.

Note: by TeamViewer I mean the full application that acts both as client and server. TeamViewer QuickSupport does not have this problem.

TeamViewer main window

TeamViewer provide their installer as a package. We use AutoPkg to obtain the package automatically, namely the TeamViewer.pkg recipe from autopkg/cgerke-recipes, which has as a parent recipe TeamViewer.download from autopkg/hjuutilainen-recipes. The .pkg recipe simply extracts the version and renames the package accordingly, but does not repackage. Our own internal .jss recipe uploads the package to our Jamf Pro distribution points.

I could not find any documentation on how to prevent the application opening, so had a look at the package using Suspicious Package, which revealed that a script named functions is sourced by the postinstall script within the package. In functions, a function restartService determines whether the application is opened or not based on the existence of ${pathToAppPath}.

TeamViewer in Suspicious Package

${pathToAppPath} is defined as a file path further up the functions file:

TeamViewer in Suspicious Package (2)

So all we need to do is ensure the file /tmp/tvPath exists before installing.

Chris Dietrich (@cdietrich on MacAdmins Slack) helpfully spotted that if the /tmp/tvPath file exists, the contents determine where TeamViewer will be installed, so we need to take care to add /Applications as the contents of the file:

## preinstall script

# Set TeamViewer to only restart the service on installation
# This is achieved by creating the following file
# before installing the package. the file should contain the
# path to which TeamViewer should be installed, as this is
# used elsewhere in the TeamViewer pkg postinstall script.
# (thanks to @cdietrich)

echo "/Applications" > /tmp/tvPath

TeamViewer Policy in Jamf Pro

We’ve added this as a preinstall script to our internal .jss recipe.