Network UPS Tools Script Assistance - raspberry-pi

Question

I've been trying to get the timing and sequencing ironed out in the upssched-cmd script, but I just can't seem to find the right path. I have a RPi3b+ running Raspbian OS that is operating as a Controller for my Unifi network and I also have an EdgeRouter Pro. I can SSH into both systems, but I cannot (or maybe too afraid to) install the NUT program on the EdgeRouter. Since I can ssh into each device, I had planed to simply deliver the halt command to the pi and shutdown command to the ER when the DietPi running as a NUT server detected the UPS moving from OnBattery to LowBattery. I could then set a timer for say 60 sec prior to the FSD being initiated and killing the DietPi and eventually rebooting the UPS prior to it going completely dead. I set the LowBattery point to 4 mins and/or 33%, so hopefully I would have plenty of time. I've never written a script before, so I have only copied from other examples and attempted to determine what it's doing:
#! /bin/sh
# SSH connection settings
ssh_host1='ControllerUser#ControllerIP'
ssh_host2='RouterUser#RouterIP'
# Misc logging
UPS="apc"
STATUS=$( upsc $UPS ups.status )
CHARGE=$( upsc $UPS battery.charge )
CHMSG="[$STATUS]:$CHARGE%"
logger -i -t upssched-cmd Calling upssched-cmd $1
case $1 in
onbatt)
message="Power Failure on UPS ${UPSNAME}!"
echo -e "Warning: UPS $UPSNAME experienced a power failure and is now running on battery!" \
| mail -s"Warning: $message" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
online)
message="Power restored on UPS $UPSNAME"
echo -e "Power on UPS $UPSNAME has been restored." \
| mail -s"$message" root
remote_cmd="log info message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
lowbatt)
message="Low battery on UPS ${UPSNAME}!"
echo -e "Warning: UPS $UPSNAME is low on battery! All connected Systems will be shut down soon." \
| mail -s"Warning: $message" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
fsd)
message="Forced Shutdown from UPS ${UPSNAME}!"
echo -e "Warning: All Systems connected to UPS $UPSNAME will be shut down now!" \
| mail -s"Warning: $message" root
remote_cmd="log error message=\"${message}\" ; beep 0.5 ; delay 4000ms ; beep 0.5 ; system shutdown!"
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 'sudo halt'
ssh $ssh_host2 'sudo shutdown'
ssh $ssh_host1 $remote_cmd
;;
commok)
message="Communications restored with UPS $UPSNAME"
echo -e "Communications with UPS $UPSNAME have been restored." \
| mail -s"$message" root
remote_cmd="log info message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
commbad)
message=""
echo -e "Warning: Lost communications with UPS ${UPSNAME}!" \
| mail -s"Warning: Lost communications with UPS ${UPSNAME}!" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
shutdown)
message="System $HOST is shutting down now!"
echo -e "Warning: System $HOST is shutting down now!" \
| mail -s"Warning: $message" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 'sudo halt'
ssh $ssh_host2 'sudo shutdown'
ssh $ssh_host1 $remote_cmd
;;
replbatt)
message="Replace battery on UPS ${UPSNAME}!"
echo -e "Warning: The UPS $UPSNAME needs to have its battery replaced!" \
| mail -s"Warning: $message" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
nocomm)
message="The UPS $UPSNAME can’t be contacted for monitoring!"
echo -e "Warning: The UPS $UPSNAME can’t be contacted for monitoring!" \
| mail -s"Warning: $message" root
remote_cmd="log warning message=\"${message}\""
#ssh $SSH_HOST -l $SSH_USER -i $SSH_KEY $remote_cmd
ssh $ssh_host1 $remote_cmd
;;
*)
logger -t upssched-cmd "Unrecognized command: $1"
;;
esac
logger -i -t upssched-cmd $message
Any guidance would be greatly appreciated!!
Thanks in advance!

Answer 1

I am not quite sure what question you are asking, however at a quick glance, that script looks like it will work.
I would suggest making a copy of the script, removing all of the shutdown and reboot commands and replacing them with a simple command for debugging (touch a file, echo to the remote terminal tty, etc), then setup everything and start doing testing.
The only way you will find out if it works or not is to test it.
I am looking at doing something similar with a raspberry pi as a NUT-server to monitor a couple UPS units and using it to shutdown some VMware ESXi servers and other network attacked equipment.
If it is alright with you, I may take some ideas from your script for my solution.