Update block lists in a dockerized version of PiHole

update_pihole_block_lists.sh

#!/bin/bash

# Update block lists in a dockerized version of PiHole
# the log file should be: update_pihole_block_lists.log
#
# run this script from cron each Saturday morning with this contab entry:
# 00 3 * * 6 /root/update_pihole_block_lists.sh

IMAGE=pihole
LENGTH=12
LOG="${0%.*}.log"
CONTAINER=$(docker ps --format "{{.ID}}" --filter name=${IMAGE})
if [ "${#CONTAINER}" -ne "${LENGTH}" ] ; then
        echo "No running container for image: ${IMAGE}"
        exit 1
fi

echo >> ${LOG}
echo >> ${LOG}
echo >> ${LOG}
echo "==============================================================" >> ${LOG}
date >> ${LOG}
echo "==============================================================" >> ${LOG}
docker exec -t ${CONTAINER} pihole updateGravity >> ${LOG} 2>&1