delete old containers

docker_clean_old.service

# /etc/systemd/system/docker_clean_old.service
[Unit]
Description=delete old containers

[Service]
CPUQuota=20%
TimeoutSec=3600
ExecStart=/bin/bash /root/opt/bin/docker_clean_old

docker_clean_old.sh

#|/bin/bash
echo "searching for old containers ..."

for c in $(docker ps -q)
do
        containerDate=$(docker inspect $c | jq '.[0].Created' | sed 's/"//g')
        untilSeconds=${containerDate%.*}
        asTimestamp=$(date -d $untilSeconds +%s)

        secondsDiff=$(($(date +%s) - $asTimestamp))

        if [ "$secondsDiff" -gt "7200" ]; then
                echo "deleting container $c, his lifetime was $secondsDiff seconds"
                docker rm -f $c
        fi
done

echo "finishing old containers' deleting ..."

docker_clean_old.timer

# /etc/systemd/system/docker_clean_old.timer
# systemctl start docker_clean_old.timer
# systemctl list-timers

[Unit]
Description=delete old containers every two hours

[Timer]
OnCalendar=0/2:00:00

[Install]
WantedBy=timers.target