do not mask NotImplementedError exceptions

[Armando Migliaccio]

Currently NotImplementedError exceptions raised by Neutron plugins are masked and returned to the client as 500 (HTTP Internal Server error). In my opinion this does more damage than good, as a client should be intelligent enough to handle the fact that a plugin implementation may be incomplete or unable to honor an API extension fully.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/35423

[yong sheng gong (gongysh)]

I think it is related to security. we may not want to expose it. client should be intelligent to know it.

[Mark McClain (markmcclain)]

@gongysh How is changing the response code from 500 to 501 a security issue? Both are errors that the client needs to handle.

[yong sheng gong (gongysh)]

@markmcclain: notimplemented is kind of internal implementation. regarding the comment in patch ' extension may or may not be implemented, if it is not implemented, the URL will not be there. anyway, I can go with it.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/35423
Committed: http://github.com/openstack/quantum/commit/6ab8dd80f6c11e1e2def99bdba62b5cf706bf47e
Submitter: Jenkins
Branch: master

commit 6ab8dd80f6c11e1e2def99bdba62b5cf706bf47e
Author: armando-migliaccio <email address hidden>
Date: Tue Jul 2 17:52:39 2013 -0700

    Do not mask NotImplementedError exceptions

    With this patch we avoid masking NotImplementedError(s).
    Previously, a catch-all clause returned 500, and it makes
    sense to distinguish between genuine 500 errors (i.e. a bug),
    versus 501 ones.

    This opens up the issue of keeping the server behavior
    consistent from one release to another, but one might argue
    that this was bad design decision in the first place.

    Fixes bug 1197200

    Change-Id: I2d81cba5ee9e5fbe8e865378381790b5b467d255