Comment 8 for bug 1831315

Added debug in: oslo_db/sqlalchemy/enginefacade.py

 455 def _url_args_for_conf(self, conf):
 456 retval = self._args_for_conf(self._url_cfg, conf)
 457 print('DEBUG _url_args_for_conf: %s' % retval)
 458 return retval

 483 def _start(self, conf=False, connection=None, slave_connection=None):
 484 print('DEBUG _start conf: %s' % conf)
 485 with self._start_lock:
 486 # self._started has been checked on the outside
 487 # when _start() was called. Within the lock,
 488 # check the flag once more to detect the case where
 489 # the start process proceeded while this thread was waiting
 490 # for the lock.
 491 if self._started:
 492 return
 493 if conf is False:
 494 conf = cfg.CONF
 495
 496 # perform register_opts() local to actually using
 497 # the cfg.CONF to maintain exact compatibility with
 498 # the EngineFacade design. This can be changed if needed.
 499 if conf is not None:
 500 conf.register_opts(options.database_opts, 'database')
 501
 502 url_args = self._url_args_for_conf(conf)

DEBUG _start conf: False
DEBUG _url_args_for_conf: {'connection': 'mysql+pymysql://nova_api:LP1VoffTn36gPLU8tz67YYEV8@[fd12:3456:789a:1::3]/nova_api?read_default_group=tripleo&read_default_file=/etc/my.cnf.d/tripleo.cnf', 'slave_connection': None}

Found 2 cell mappings.
Skipping cell0 since it does not contain hosts.
Getting computes from cell 'default': 4165e8f0-6bbc-4b61-86c7-208ba08f0589

DEBUG _start conf: False
DEBUG _url_args_for_conf: {'connection': u'mysql+pymysql://nova:LP1VoffTn36gPLU8tz67YYEV8@fd12:3456:789a:1::3/nova?read_default_group=tripleo&read_default_file=/etc/my.cnf.d/tripleo.cnf', 'slave_connection': None}

An error has occurred:
Traceback (most recent call last):
 <--- snip --->

Something must be editing that config somewhere?