Incorrectly specifying an aggregate function when requesting statistics causes 500 instead of the correct 400

[Chris Dent]

When requesting statistics from the ceilometer api and asking for just one aggregate function, if you make the request wrongly and state "aggregate=max" instead of "aggregate.func=max" a 500 is raised from an untrapped AttributeError. Note that if you specify a completely unknown parameter (such as "moo=cow") a 400 is raised. A 400 is what we would expect when any parameter is wrong.

    - name: get sample statistics select aggregate bad format
      desc: causes 500 with uncaught AttributeError
      xfail: true
      url: /v2/meters/apples/statistics?aggregate=max
      status: 400

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/208467

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/208467
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=d7428b7c3873bb47683c4f4d547fce138b79a74b
Submitter: Jenkins
Branch: master

commit d7428b7c3873bb47683c4f4d547fce138b79a74b
Author: Mehdi Abaakouk <email address hidden>
Date: Mon Aug 3 14:41:42 2015 +0200

    Update tests to reflect WSME 0.8 fixes

    All these bugs are now fixed in wsme 0.8.0

    Closes-bug: #1424642
    Closes-bug: #1423634
    Closes-bug: #1419110
    Closes-bug: #1428185
    Closes-bug: #1428628
    Closes-bug: #1428658
    Closes-bug: #1428624

    Change-Id: Iea8507ebc54f42786a44bfcd96246b88dd998bf0