#!/usr/bin/env python3
# Author: Maurice Makaay, XS4ALL
# {{ ansible_managed }}
#
# This script is used to find out what the latest recorded transaction
# on this host is. It is used by the galera cluster bootstrapping
# script (which is available in /root/bootstrap_galera_cluster on the
# ansible host) to find out in what order to start the nodes in case
# of an unclean full shutdown of the cluster.
#
# DO NOT RUN FOR FUN! This script will bring down the mysql service
# when it is not already down. 
#

import subprocess
import re
import json
from sys import exit


subprocess.check_output(["service", "mysql", "stop"])
result = subprocess.check_output(
    ['mysqld', '--wsrep-recover'], stderr= subprocess.STDOUT)

info = re.compile('WSREP: Recovered position: (.+)\s*$')
for line in result.split("\n"):
    result = info.search(line)
    if result is not None:
        print(json.dumps(result.group(1)))
        exit(0)

print(json.dumps(None))