mirror of
https://github.com/outbackdingo/patroni.git
synced 2026-08-31 08:39:34 +00:00
Alexander Kukushkin
d202f72a42
Server always returns json which contains some status of postgres: * instance type: master/slave * xlog location for master * xlog received_location, replayed_location This server could be used by haproxy GET / returns 200 if there is postgres master behind governor. GET /slave returns 200 is there is postgres slave behind governor In all other cases it returns 503 Currently server always listening on 0.0.0.0:8080, but it should be configurable. In the next versions this rest api could also report some status of etcd and could be used by is_healthiest_node method
97 lines
2.7 KiB
Python
Executable File
97 lines
2.7 KiB
Python
Executable File
#!/usr/bin/env python
|
|
|
|
import logging
|
|
import os
|
|
import signal
|
|
import sys
|
|
import time
|
|
import yaml
|
|
|
|
from helpers.api import RestApiServer
|
|
from helpers.etcd import Etcd
|
|
from helpers.postgresql import Postgresql
|
|
from helpers.ha import Ha
|
|
|
|
|
|
def sigterm_handler(signo, stack_frame):
|
|
sys.exit()
|
|
|
|
|
|
# handle SIGCHILD, since we are the equivalent of the INIT process
|
|
def sigchld_handler(signo, stack_frame):
|
|
try:
|
|
while True:
|
|
ret = os.waitpid(-1, os.WNOHANG)
|
|
if ret == (0, 0):
|
|
break
|
|
except OSError:
|
|
pass
|
|
|
|
|
|
class Governor:
|
|
|
|
def __init__(self, config):
|
|
self.nap_time = config['loop_wait']
|
|
self.etcd = Etcd(config['etcd'])
|
|
self.postgresql = Postgresql(config['postgresql'])
|
|
self.ha = Ha(self.postgresql, self.etcd)
|
|
|
|
def touch_member(self):
|
|
return self.etcd.touch_member(self.postgresql.name, self.postgresql.connection_string)
|
|
|
|
def initialize(self):
|
|
# wait for etcd to be available
|
|
while not self.touch_member():
|
|
logging.info('waiting on etcd')
|
|
time.sleep(5)
|
|
|
|
# is data directory empty?
|
|
if self.postgresql.data_directory_empty():
|
|
# racing to initialize
|
|
if self.etcd.race('/initialize', self.postgresql.name):
|
|
self.postgresql.initialize()
|
|
self.etcd.take_leader(self.postgresql.name)
|
|
self.postgresql.start()
|
|
self.postgresql.create_replication_user()
|
|
else:
|
|
while True:
|
|
leader = self.etcd.current_leader()
|
|
if leader and self.postgresql.sync_from_leader(leader):
|
|
self.postgresql.write_recovery_conf(leader)
|
|
self.postgresql.start()
|
|
break
|
|
time.sleep(5)
|
|
elif self.postgresql.is_running():
|
|
self.postgresql.load_replication_slots()
|
|
|
|
def run(self):
|
|
while True:
|
|
self.touch_member()
|
|
logging.info(self.ha.run_cycle())
|
|
time.sleep(self.nap_time)
|
|
|
|
|
|
def main():
|
|
if len(sys.argv) < 2 or not os.path.isfile(sys.argv[1]):
|
|
print('Usage: {} config.yml'.format(sys.argv[0]))
|
|
return
|
|
|
|
with open(sys.argv[1], 'r') as f:
|
|
config = yaml.load(f)
|
|
|
|
governor = Governor(config)
|
|
try:
|
|
governor.initialize()
|
|
RestApiServer(governor).start()
|
|
governor.run()
|
|
finally:
|
|
governor.postgresql.stop()
|
|
governor.etcd.delete_leader(governor.postgresql.name)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=logging.INFO)
|
|
signal.signal(signal.SIGTERM, sigterm_handler)
|
|
signal.signal(signal.SIGCHLD, sigchld_handler)
|
|
main()
|