Jamf script template to install or remove a specified homebrew formula as part of a policy

macOS-BrewFormula-Template.sh

#!/bin/bash

# Script template to install or remove an installed homebrew
# formula.

# Variable to supply as part of the assigned Jamf policy to
# install or remove the specified brew formula
BREW_ITEM="$4"
# Comment out the undesired BREW_ACTION
BREW_ACTION="install"
#BREW_ACTION="remove"
# Custom trigger to install Homebrew if not installed
BREW_INSTALL_TRIGGER="<your custom trigger>"
# Get logged-in user
CURRENT_USER=$(echo "show State:/Users/ConsoleUser" | scutil | awk '/Name :/ { print $3 }')

brewCheck() {
	BREW_PATH=$(which brew)
}

brewInstall() {
	/bin/echo "Brew not installed. Installing..."
	
	# Install brew
	jamf policy -event "$BREW_INSTALL_TRIGGER"
}

brewProcessFormula() {
	# Process the brew item
	/usr/bin/su - "$CURRENT_USER" -c "\"${BREW_PATH}\" ${BREW_ACTION} ${BREW_ITEM}"
	exitcode=$(/bin/echo $?)

	if [ "$exitcode" = 0 ]; then
		
		if [ "$BREW_ACTION" = "install" ]; then
			ACTION="installed"
		elif [ "$BREW_ACTION" = "remove" ]; then
			ACTION="removed"
		fi

		/bin/echo "Successfully ${ACTION} ${BREW_ITEM} for user ${CURRENT_USER}!"
		exit 0
	else
		/bin/echo "Failed to ${BREW_ACTION} ${BREW_ITEM} for user ${CURRENT_USER}."
		exit 1
	fi
}

brewUpgradeFormula () {
	# Update the brew item
	/bin/echo "Brew formula ${BREW_ITEM} already installed. Attempting to upgrade..."
	/usr/bin/su - "$CURRENT_USER" -c "\"${BREW_PATH}\" upgrade ${BREW_ITEM}"
}

# Make sure we have a brew item to process
if [ -z "$BREW_ITEM" ]; then
	/bin/echo "'$4' is empty. Need to specify an item to ${BREW_ACTION}."
fi

brewCheck

# Make sure brew is installed
if [ -z "$BREW_PATH" ]; then
	
	brewInstall
	
	brewCheck
	
	# Make sure we have brew now
	if [ ! -z "$BREW_PATH" ]; then
		/bin/echo "Successfully installed brew. Continuing with ${BREW_ACTION} of ${BREW_ITEM}..."
	else
		/bin/echo "Failed to install brew. Exiting..."
		exit 1
	fi
fi

# Make sure not already installed, grep exact match
BREW_ITEM_CHECK=$(/usr/bin/su - "$CURRENT_USER" -c "\"${BREW_PATH}\" list | /usr/bin/grep -w \"^${BREW_ITEM}$\"")

if [ "$BREW_ACTION" = "install" ] && [ -z "$BREW_ITEM_CHECK" ]; then
	brewProcessFormula
elif [ "$BREW_ACTION" = "install" ] && [ ! -z "$BREW_ITEM_CHECK" ] ; then
	brewUpgradeFormula
elif [ "$BREW_ACTION" = "remove" ] && [ ! -z "$BREW_ITEM_CHECK" ]; then
	brewProcessFormula
else
	/bin/echo "ERROR: Unaccounted for logic or unique issue."
	exit 1
fi