How to mount another EBS as /var on EC2 (ubuntu)

mount_ebs.sh

#!/bin/bash
#attach the EBS to /dev/sdf before running it

UPDATE=yes

while getopts d:u option
do
case "${option}"
in
d) DEVICE=${OPTARG};;
u) UPDATE=${OPTARG};;
esac
done

findroot=$(findmnt -n -o SOURCE --target /)
findvar=$(findmnt -n -o SOURCE --target /var)

if [ "$findroot" = "$findvar" ]; then
  echo we need to move /var
else
  echo var already separate partition
  exit
fi

echo "Using $DEVICE for /var"

#format EBS
mkfs -t ext4 $DEVICE

#copy original /var to $DEVICE
mkdir /mnt/new
mount $DEVICE /mnt/new
cd /var
cp -ax * /mnt/new
cd /
mv var var.old

#mount EBS as new /var
umount $DEVICE
mkdir /var
mount $DEVICE /var

if [ "$UPDATE" = "yes" ]
  ## Get ID for fstab entry
  # lsblk -o +UUID
  fs_uuid=$(lsblk -no UUID $DEVICE)

  #update fstab file to mount EBS on system startup
  echo "$fs_uuid /var ext4 noatime,nofail 0 0" >> /etc/fstab
else
  echo "CAUTION: Not updating /etc/fstab."
fi

Updated for new instance type.