Many classes lack @six.add_metaclass decoration

[John Perkins]

There are roughly a dozen classes in Neutron that define abstract methods or properties but are not decorated with @six.add_metaclass(abc.ABCMeta). Without this decoration, children can be created without defining the required methods or properties.

Decorating RBACColumns in db/rbac_db_models.py causes failures and will be reported separately.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/311930

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/311930
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=972cdef50cd32837b8328466e4d821bb36535130
Submitter: Jenkins
Branch: master

commit 972cdef50cd32837b8328466e4d821bb36535130
Author: John Perkins <email address hidden>
Date: Mon May 2 22:52:51 2016 -0600

    Classes lack metaclass decoration

    Add decorations where required.

    There are roughly a dozen classes in Neutron that define abstract
    methods or properties but are not decorated with
    @six.add_metaclass(abc.ABCMeta). Without this decoration, children
    can be created without defining the required methods or properties.

    Decorating RBACColumns in db/rbac_db_models.py causes failures and will
    be reported separately.

    Decorating unit tests is of dubious benifit and should be addressed
    separately (if at all).

    There are also several more places where metaclassing isn't correct, to
    be taken care of in follow-on patches.

    For example, BaseScheduler is using the fact the None doesn't have a
    filter_agents() method, which gives developers confusing error messages
    when they incorrectly implement the interface, and they won't see any
    error until schedule() is called. As an aside, the docstring for this
    base class is also incorrect.

    Change-Id: I2b2cce37d9b0d40559a715a7d510a969b8ba9963
    Closes-Bug: #1577648

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/neutron 9.0.0.0b1 development milestone.