mariadb: Add missing backup script

roles/mariadb/files/mariadb-backup.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+set -eu
+
+umask 077
+
+DESTDIR="/export/backup"
+DATE="$(date +%Y-%m-%d)"
+
+if [ ! -d "$DESTDIR" ]; then
+    echo "ERR: MariaDB backup directory [${DESTDIR}] does not exist" 1>&2
+    exit 1
+fi
+
+cd "$DESTDIR" && {
+    find . -xdev -mindepth 2 -maxdepth 2 -type f -mtime +7 \
+        -execdir rm -f -- {} \;
+    find . -xdev -depth -mindepth 1 -maxdepth 1 -type d -empty \
+        -execdir rmdir -- {} \;
+}
+
+DESTDIR="${DESTDIR}/${DATE}"
+mkdir -p "$DESTDIR"
+
+for db in $(mysql -e "show databases" -s) ; do
+    case "$db" in
+        Database|information_schema|performance_schema)
+            continue
+            ;;
+    esac
+    mysqldump -E --add-drop-table "$db" | gzip > "${DESTDIR}/${db}.${DATE}.gz"
+done