Here's my script, it's 1.5 years old and I've come a long way with bash since then, so it could be a lot cleaner and shorter (but it works). It's designed to provide local logs and echo results to the JSS policy logs as well. You will need to make sure you have a trigger policy set up that applies your FV configuration.
I also have a "reminder" policy that runs once per day for all systems that are in "deferred" mode, popping up a CocoaDialog reminder that encryption is required, please log out and enter your password, etc.
#!/bin/bash
#
# FV2 Enable
# Runs basic checks, if FV2 is not active or deferred and current user is not admin, enables FV2
log() {
if [ "$1" ]; then
echo $1>>$logPath
fi
}
DATESTAMP=`date`
logPath="/var/log/Deployments/FileVault2.log"
if [ ! -d "/var/log/Deployments" ]; then
mkdir "/var/log/Deployments"
fi
log "Running FV2 Enable - $DATESTAMP"
log "Computer name: `hostname`"
currentUser=`ls -l /dev/console | awk '{print $3}'`
isUserLoggedIn=`who | grep console | grep $currentUser`
# Quit out if administrator is logged in
if [ $currentUser = "administrator" ]; then
log "administrator logged on, exiting"
echo "administrator logged on, exiting"
exit 0
fi
FVStatus=`fdesetup status`
# If FV is already on, exit
isOn=`echo $FVStatus | grep "FileVault is On"`
if [ "$isOn" ]; then
log "FileVault is On. Exiting."
echo "FileVault is On. Exiting."
exit 0
fi
# If FV is in a deferred state already, exit
isDef=`fdesetup status | grep Deferred`
if [ "$isDef" ]; then
log "$isDef"
defUserResult=`echo $isDef | awk '{print $9}'`
strLen=`echo ${#defUserResult}`
defUsername=`echo "${defUserResult:1:$strLen-3}"`
log "$defUsername is already set as the deferred FV user. Exiting."
echo "$defUsername is already set as the deferred FV user. Exiting."
exit 0
fi
# if FV is encrypting, exit
isEnc=`echo $FVStatus | grep "Encryption in progress"`
if [ "$isEnc" ]; then
log "$FVStatus"
echo "$FVStatus"
exit 0
fi
# if FV is decrypting, exit
isDec=`echo $FVStatus | grep "Decryption in progress"`
if [ "$isDec" ]; then
log "$FVStatus"
echo "$FVStatus"
exit 0
fi
# Make sure user is logged on
if [ ! "$isUserLoggedIn" ]; then
log "Current console user is not logged on"
echo "Current console user is not logged on"
exit 0
fi
log "$currentUser currently logged in"
# All checks passed, enable FV2 for currently logged in user
log "Executing FV2 enable policy"
jamf policy -trigger enableFV2
sleep 5
FVStatus=`fdesetup status`
log "$FVStatus"
echo "$FVStatus"
