#!/bin/bash

# in case the mysql db is located in docker container.
append_cli=$4
# For taking backup
backup_dir=/media/storage/backup/db_backup/
datestamp=$(date +%d-%m-%y-%H-%M)
db_user=backup
db_port=$2
db_pass=$3
host=$1

die() {
    echo >&2 "$@"
    exit 1
}

[ "$(id -u)" = 0 ] || die "Must be root to run script"
[ -n "$host" ] || die "host not passed."
[ -n "$db_port" ] || die "PORT not passed."

# remove backups older than $days_keep
days_keep=7
find ${backup_dir}* -mtime +$days_keep -exec rm -f {} \; 2> /dev/null
# create backups securely
umask 006
# list MySQL databases and dump each
IFS=$'\n' read -d '' -r -a db_list \
 < <($append_cli mysql -h $host -u $db_user -p"$db_pass" --batch --skip-column-names -e'show databases where `Database` not REGEXP "^mysql|^sys" AND `Database` not like "%_schema";')

echo "Listing databases"
echo ${db_list##Database}

for db in ${db_list[@]};

do
 FILENAME=${backup_dir}${db}-${datestamp}.${db_port}.gz
 echo "Initiating backup of $DB for ${host} on port ${db_port}"
 $append_cli mysqldump -h $host -P $db_port -u $db_user -p"$db_pass" $db --single-transaction | gzip > $FILENAME
 echo "Done backing up ${FILENAME}"
done