Remaining issues encountered when running with SQLAlchemy 2.0 for real:
* Never call str() on a URL and expect it to be meaningful anymore.
The password is aggressively obfuscated now (users absolultely
wouldn't let us leave it as is)
* More utilities and fixtures that were calling begin() within a
block that would have already begun
* isnot is now called is_not; mocking "isnot" leads into too many
weird compat layers
* ORM InstrumentedAttribute and internals use __slots__ now, mock
seems to not be able to patch methods. Ideally these tests would use
a comparator subclass or something
* Connection.connection.connection is now called driver_connection,
SQLAlchemy keeps the old name available however oslo.db test suite
does not appear to tolerate the deprecation warning emitted,
so add a compat layer
* mapper() is fully removed from 2.0, not sure if there is another
not-yet-committed gerrit that removes mapper()
[1] https://docs.sqlalchemy.org/en/20/core/engines.html#sqlalchemy.create_engine.params.pool_pre_ping
[2] https://docs.sqlalchemy.org/en/20/changelog/changelog_20.html#change-2fe37eaf2295cebd3bb4ee8e5b8c575c
[3] https://github.com/sqlalchemy/sqlalchemy/issues/5648
Change-Id: Ifaca67c07f008d8bc0febeecd3e200cc7ee7a4b0
1f003bcb0b