No validation for session-persistance when creating a VIP.

[Roman Prykhodchenko]

LBaaS API specification contains wrong validation rule for VIPs' session-persistence:

    'session_persistence': {'allow_post': True, 'allow_put': True,
                            'default': {},
                            'validate': {'type:dict': None},
                            'is_visible': True}

The rule specifies the only constraint for a supplied value to be a dictionary. However, the schema of the database defines strict constraints for SessionPersistence objects:

    type = sa.Column(sa.Enum("SOURCE_IP",
                             "HTTP_COOKIE",
                             "APP_COOKIE",
                             name="sesssionpersistences_type")

According to the constraint above 'type' is mandatory for SessionPersistence objects and it has to be equal to "SOURCE_IP", "HTTP_COOKIE" or "APP_COOKIE". The extension, however, does not check whether type is specified in the request and is equal to one of the allowed values. This causes an IntergityError to be thrown by the database and a user gets an Internal server error, if wrong type was specified.

[Avishay Balderman (avishayb)]

If those constaraints could be defined ONLY ONCE we could skip this bug and more bugs from this 'family' in the future.

[Roman Prykhodchenko (romcheg)]

I have prepaired a patch for advanced validation of dict values for the API. I think it's reasonable to use it to fix this issue.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/20487

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/20487
Committed: http://github.com/openstack/quantum/commit/a5c101da4bd6371fdc116690ef0c354868a571b0
Submitter: Jenkins
Branch: master

commit a5c101da4bd6371fdc116690ef0c354868a571b0
Author: Roman Prykhodchenko <email address hidden>
Date: Fri Jan 25 17:44:21 2013 +0200

    Support advanced validation of dictionaries in the API.

    This change allows to specify constraints for individual keys in
    dictionaries in the specification of the API resources.

    Introduces type:dict_or_none validator that allows to skip
    validation of a dictionary if a None value was supplied.

    Adds constraints for session persistance parameters to the API.

    Disables specifying cookie_name for session persistence, if
    the type is set to HTTP_COOKIE or SOURCE_IP.

    Fixes: bug #1104110

    Change-Id: I62068deed449967949eaba9259028c88dd6974f8