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https://github.com/outbackdingo/patroni.git
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103 lines
3.1 KiB
Python
Executable File
103 lines
3.1 KiB
Python
Executable File
#!/usr/bin/env python
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import logging
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import os
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import signal
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import sys
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import time
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import yaml
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from helpers.api import RestApiServer
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from helpers.etcd import Etcd
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from helpers.postgresql import Postgresql
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from helpers.ha import Ha
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def sigterm_handler(signo, stack_frame):
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sys.exit()
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# handle SIGCHILD, since we are the equivalent of the INIT process
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def sigchld_handler(signo, stack_frame):
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try:
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while True:
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ret = os.waitpid(-1, os.WNOHANG)
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if ret == (0, 0):
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break
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except OSError:
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pass
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class Governor:
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def __init__(self, config):
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self.nap_time = config['loop_wait']
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self.etcd = Etcd(config['etcd'])
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self.postgresql = Postgresql(config['postgresql'])
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self.ha = Ha(self.postgresql, self.etcd)
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host, port = config['restapi']['listen'].split(':')
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self.api = RestApiServer(self, config['restapi'])
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def touch_member(self, ttl=None):
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connection_string = self.postgresql.connection_string + '?application_name=' + self.api.connection_string
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return self.etcd.touch_member(self.postgresql.name, connection_string, ttl)
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def initialize(self):
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# wait for etcd to be available
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while not self.touch_member():
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logging.info('waiting on etcd')
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time.sleep(5)
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# is data directory empty?
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if self.postgresql.data_directory_empty():
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# racing to initialize
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if self.etcd.race('/initialize', self.postgresql.name):
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self.postgresql.initialize()
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self.etcd.take_leader(self.postgresql.name)
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self.postgresql.start()
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self.postgresql.create_replication_user()
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self.postgresql.create_connection_users()
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else:
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while True:
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leader = self.etcd.current_leader()
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if leader and self.postgresql.sync_from_leader(leader):
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self.postgresql.write_recovery_conf(leader)
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self.postgresql.start()
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break
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time.sleep(5)
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elif self.postgresql.is_running():
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self.postgresql.load_replication_slots()
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def run(self):
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self.api.start()
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while True:
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self.touch_member()
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logging.info(self.ha.run_cycle())
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time.sleep(self.nap_time)
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def main():
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logging.basicConfig(format='%(asctime)s %(levelname)s: %(message)s', level=logging.INFO)
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signal.signal(signal.SIGTERM, sigterm_handler)
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signal.signal(signal.SIGCHLD, sigchld_handler)
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if len(sys.argv) < 2 or not os.path.isfile(sys.argv[1]):
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print('Usage: {} config.yml'.format(sys.argv[0]))
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return
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with open(sys.argv[1], 'r') as f:
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config = yaml.load(f)
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governor = Governor(config)
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try:
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governor.initialize()
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governor.run()
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finally:
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governor.touch_member(300) # schedule member removal
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governor.postgresql.stop()
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governor.etcd.delete_leader(governor.postgresql.name)
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if __name__ == '__main__':
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main()
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