this script can be used to auto-update your pi-hole docker instance

pi-hole-update.sh

#!/bin/bash

need_restart=no

# ---
function restart_pihole() {
  cd /root/pihole && {
    docker-compose --ansi never pull 2>&1
    docker-compose --ansi never stop && docker-compose --ansi never up -d
  }
}
# ---

# ---
function check_for_image() {
  cd /root/pihole &&
    docker-compose --ansi never pull 2>&1 | grep "is up to date" || need_restart=yes
}
# ---

# ---
# MAIN
# ---
check_for_image
[ "$need_restart" == "yes" ] && restart_pihole
# ---