Create database from models for SQLite

Alembic does not support SQLite, and we don't recommend to use SQLite
in production deployments, so migrations are rarely needed for SQLite.
So we don't bother about working around SQLite limitations, and create
database from models when it is in use. Of course, we still use
alembic to migrate schema on 'real' databases.

Change-Id: I8237a29c7bf5b60136bb1b72fd029fe9ce1abe1f

taskflow/persistence/backends/impl_sqlalchemy.py

@@ -92,7 +92,7 @@ POSTGRES_GONE_WAY_AWAY_ERRORS = (
 )
 
 # These connection urls mean sqlite is being used as an in-memory DB
-SQLITE_IN_MEMORY = ("sqlite://", 'sqlite:///:memory:')
+SQLITE_IN_MEMORY = ('sqlite://', 'sqlite:///', 'sqlite:///:memory:')
 
 
 def _in_any(reason, err_haystack):
@@ -290,7 +290,16 @@ class Connection(base.Connection):
     def upgrade(self):
         try:
             with contextlib.closing(self._engine.connect()) as conn:
-                migration.db_sync(conn)
+                # NOTE(imelnikov): Alembic does not support SQLite,
+                # and we don't recommend to use SQLite in production
+                # deployments, so migrations are rarely needed
+                # for SQLite. So we don't bother about working around
+                # SQLite limitations, and create database from models
+                # when it is in use.
+                if 'sqlite' in self._engine.url.drivername:
+                    models.BASE.metadata.create_all(conn)
+                else:
+                    migration.db_sync(conn)
         except sa_exc.SQLAlchemyError as e:
             raise exc.StorageError("Failed upgrading database version: %s" % e,
                                    e)