def run(config):
etcd = Etcd(config["etcd"])
postgresql = Postgresql(config["postgresql"])
ha = Ha(postgresql, etcd)
atexit.register(stop_postgresql, postgresql)
signal.signal(signal.SIGTERM, signalhandler)
logging.info("Governor Starting up")
# is data directory empty?
if postgresql.data_directory_empty():
logging.info("Governor Starting up: Empty Data Dir")
# racing to initialize
wait_for_etcd("cannot initialize member without ETCD", etcd, postgresql)
if etcd.race("/initialize", postgresql.name):
logging.info("Governor Starting up: Initialisation Race ... WON!!!")
logging.info("Governor Starting up: Initialise Postgres")
postgresql.initialize()
logging.info("Governor Starting up: Initialise Complete")
etcd.take_leader(postgresql.name)
logging.info("Governor Starting up: Starting Postgres")
postgresql.start()
else:
logging.info("Governor Starting up: Initialisation Race ... LOST")
logging.info("Governor Starting up: Sync Postgres from Leader")
synced_from_leader = False
while not synced_from_leader:
leader = etcd.current_leader()
if not leader:
time.sleep(5)
continue
if postgresql.sync_from_leader(leader):
logging.info("Governor Starting up: Sync Completed")
postgresql.write_recovery_conf(leader)
logging.info("Governor Starting up: Starting Postgres")
postgresql.start()
synced_from_leader = True
else:
time.sleep(5)
else:
logging.info("Governor Starting up: Existing Data Dir")
postgresql.follow_no_leader()
logging.info("Governor Starting up: Starting Postgres")
postgresql.start()
wait_for_etcd("running in readonly mode; cannot participate in cluster HA without etcd", etcd, postgresql)
logging.info("Governor Running: Starting Running Loop")
while True:
try:
logging.info("Governor Running: %s" % ha.run_cycle())
# create replication slots
if postgresql.is_leader():
logging.info("Governor Running: I am the Leader")
for node in etcd.members():
member = node["hostname"]
if member != postgresql.name:
if postgresql.is_leader():
postgresql.ensure_replication_slot(
postgresql.replication_slot_name(member)
)
else:
postgresql.drop_replication_slot(
postgresql.replication_slot_name(member)
)
etcd.touch_member(postgresql.name, postgresql.connection_string)
time.sleep(config["loop_wait"])
except (urllib2.URLError, socket.timeout):
logging.info("Lost connection to etcd, setting no leader and waiting on etcd")
postgresql.follow_no_leader()
wait_for_etcd("running in readonly mode; cannot participate in cluster HA without etcd", etcd, postgresql)
