'st2ctl reload' bundled in packaging fails on first st2 install

In curl | bash script we configure mongo with specific username/password and permissions.

During the apt/yum install we automatically trigger st2ctl reload --register-runners --register-fail-on-failure via packaging postinst.

That fails, because when installing StackStorm for the first time, st2.conf is shipped with default values and so mongo user doesn't have needed permissions:

  Installing : st2-2.2.1-3.x86_64                                                                                                                                                 15/15 
Registering content...[flags = --register-runners --register-fail-on-failure]
2017-03-23 17:28:52,705 INFO [-] Connecting to database "st2" @ "0.0.0.0:27017" as user "None".
Traceback (most recent call last):
  File "/usr/bin/st2-register-content", line 22, in <module>
    sys.exit(content_loader.main(sys.argv[1:]))
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/content/bootstrap.py", line 384, in main
    setup(argv)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/content/bootstrap.py", line 376, in setup
    common_setup(config=config, setup_db=True, register_mq_exchanges=True)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/script_setup.py", line 86, in setup
    db_setup()
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/database_setup.py", line 43, in db_setup
    ssl_match_hostname=cfg.CONF.database.ssl_match_hostname)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/persistence/db_init.py", line 65, in db_setup_with_retry
    ssl_match_hostname=ssl_match_hostname)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/retrying.py", line 206, in call
    return attempt.get(self._wrap_exception)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/retrying.py", line 247, in get
    six.reraise(self.value[0], self.value[1], self.value[2])
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/retrying.py", line 200, in call
    attempt = Attempt(fn(*args, **kwargs), attempt_number, False)
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/models/db/__init__.py", line 94, in db_setup
    db_ensure_indexes()
  File "/opt/stackstorm/st2/lib/python2.7/site-packages/st2common/models/db/__init__.py", line 131, in db_ensure_indexes
    raise e
pymongo.errors.OperationFailure: not authorized on st2 to execute command { createIndexes: "user_d_b", indexes: [ { unique: true, background: false, sparse: false, key: { name: 1 }, name: "name_1" } ] }

Start with scripts/st2bootstrap-deb.sh at the Mongo configuration lines 228-250 and packages/st2/rpm/postinst_script.spec, then reproduce the first apt/yum installation and its st2ctl reload. Trace how the shipped st2.conf reaches the registration command and verify that a first install completes registration without the MongoDB authorization failure.