Perform linux maintenance across multiple boxes with ease using screens

linuxmaintenance.sh

#!/bin/bash
# linuxmaintenance.sh
# Authored Sep 7 2018 by Jim
# Optimized Jan 4 2019 by Jeffery Grantham
# You must have a file named hosts.txt containing each hostname or FDQN for the boxes of which maintenance will be performed
# Hosts/FQDNs must have 1 listed per line for the script to execute properly
# run-updates script must be on target boxes and included in the PATH for the root user

# Checking if screen is installed. If not, apt will install it.
if [[ $(which screen) != "/usr/bin/screen" ]]; then 
  apt install screen -y
fi

# Proceeding with screen creation for each host
for HOST in `cat ~/bin/hosts.txt`
do
echo $HOST
screen -d -m -S $HOST ssh root@$HOST
screen -r $HOST -p0 -X stuff "$(echo -ne '\001\013') { run-updates.sh && exit ; } $(echo -ne '\015')"
done

# Resume each screen in sequential order in the same window. E.g. exit ; screen -r (nextscreen)
for line in `screen -ls | grep Detached |  awk '{print $1}'`
do `screen -r $line`
done