#!/bin/sh

set -eu

umask 027

DESTDIR="/srv/backup"
DATE="$(date +%Y-%m-%d)"

cd "$DESTDIR"
find . -xdev -mindepth 2 -maxdepth 2 -type f -mtime +30 \
    -execdir rm -f -- {} \;
find . -xdev -depth -mindepth 1 -maxdepth 1 -type d -empty \
    -execdir rmdir -- {} \;

mkdir -m 2770 "$DATE"
chgrp backup "$DATE"

for db in $(mysql -e "show databases" -s) ; do
    case "$db" in
        Database|information_schema|performance_schema)
            continue
            ;;
    esac
    mysqldump -E --add-drop-table "$db" | gzip > "${DATE}/${db}.${DATE}.gz"
done