Backup MariaDB data running in a Docker container

backup-mariadb.sh

#!/bin/bash
BASE=`date -I`-mariabackup
CONT=mariadb
DEST=/home/matt/_gdrive/mariabackup/
MAGE=365
OWNER=matt:matt
TGZ=$DEST$BASE.tgz

# check if the container is running
if [ "$( docker container inspect -f '{{.State.Running}}' $CONT )" == "true" ]; then
        docker exec $CONT mariabackup --backup --target-dir=/var/lib/mysql/$BASE --user=root
        cd $DEST
        tar -c -C /var/lib/mysql/$BASE/ . | gzip --rsyncable > $TGZ
        chown $OWNER $TGZ
        rm -rf /var/lib/mysql/$BASE
#cleanup older than max age
        if [ "$(find $DEST -mtime +$MAGE | wc -l)" -ge 1 ]; then
                echo "Cleaning up backups older than $MAGE days..."
                find $DEST -mtime +$MAGE -delete -print
        fi 
else
        echo "$CONT is not running. Exiting."
        exit 1
fi