Fix db management: don't autocreate db on start

We should use sahara-db-manage for db creation instead of auto created
db schema from metadata. This approach was applied by adding support for
alembic-based migrations and db autocreation code was removed in
I14a0602bb34bf09086428766cb681345191436fe, but it one more place where
we're autocreating db was missed, so, it's a fix for this issue.

Additionally, cleanup custom hacking check for sahara.db calls.
Docs already contains notes about need for using sahara-db-manage for
database creation.

Note: The main driver in fixing this right now is that if a user create
database from metadata, he will not be able to migrate from Icehouse to
Juno. Only databases created by alembic could be migrated to the later
version.

Closes-Bug: #1300190
Change-Id: I991aa3402f658999735ad9607544251a6ef0e122

sahara/cli/sahara_api.py

@@ -38,7 +38,6 @@ gettext.install('sahara', unicode=1)
 
 
 from sahara import config
-from sahara.db import api as db_api
 import sahara.main as server
 from sahara.openstack.common import log as logging
 
@@ -58,9 +57,6 @@ def main():
     config.parse_configs(sys.argv[1:], config_files)
     logging.setup("sahara")
 
-    if not db_api.setup_db():
-        raise RuntimeError('Failed to create database!')
-
     app = server.make_app()
 
     wsgi.server(eventlet.listen((cfg.CONF.host, cfg.CONF.port), backlog=500),

sahara/utils/hacking/checks.py

@@ -39,9 +39,7 @@ def import_db_only_in_conductor(logical_line, filename):
     if _any_in(filename,
                "sahara/conductor",
                "sahara/tests",
-               "sahara/db",
-               "sahara/main.py",
-               "sahara/cli"):
+               "sahara/db"):
         return
 
     if _starts_with_any(logical_line,