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On Aug 8, 2014, at 8:49 AM, Pendergrass, Eric <eric.pendergrass at hp.com> wrote:

> Hi,
>  
> We have been struggling to get a decorator working for proposed new RBAC functionality in ceilometer-api.  We’re hitting a problem where GET request query parameters are mucked up by our decorator.  Here’s an example call:
>  
> curl -H "X-Auth-Token:$TOKEN" 'http://localhost:8777/v2/meters?q.field=project_id&q.value=8c678720fb5b4e3bb18dee222d7d7933'
>  
> And here’s the decorator method (we’ve tried changing the kwargs, args, etc. with no luck):
>  
> _ENFORCER = None
>  
> def protected(controller_class):
>  
>     global _ENFORCER
>     if not _ENFORCER:
>         _ENFORCER = policy.Enforcer()
>  
>     def wrapper(f):
>         @functools.wraps(f)
>         def inner(self, **kwargs):
>             pdb.set_trace()
>             self._rbac_context = {}

You need to be careful saving request state on the controller. The controller may be shared by multiple requests (I see below that you’re creating a MeterController for each incoming request, but that won’t be the case for all controller types). It’s better to store the value in the pecan.request, which is a thread-safe request-specific object.

If you just need to store some values, and not test ACLs it in the decorator, you could use a Pecan hook [1] like we do with the configuration settings [2].

Doug

1 - http://pecan.readthedocs.org/en/latest/hooks.html
2 - http://git.openstack.org/cgit/openstack/ceilometer/tree/ceilometer/api/hooks.py#n27

>             if not _ENFORCER.enforce('context_is_admin',
>                                      {},
>                                      {'roles': pecan.request.headers.get('X-Roles', "").split(",")}):
>                 self._rbac_context['project_id'] = pecan.request.headers.get('X-Project-Id')
>                 self._rbac_context['user_id'] = pecan.request.headers.get('X-User-Id')
>             return f(self, **kwargs)
>         return inner
>     return wrapper
>  
> tried this too:
>  
> _ENFORCER = None
>  
> def protected(*args):
>  
>     controller_class = 'meter'
>     global _ENFORCER
>     if not _ENFORCER:
>         _ENFORCER = policy.Enforcer()
>  
>     def wrapper(f, *args):
>         def inner(self, *args):
>             pdb.set_trace()
> #            self._rbac_context = {}
> #            if not _ENFORCER.enforce('context_is_admin',
> #                                     {},
> #                                     {'roles': pecan.request.headers.get('X-Roles', "").split(",")}):
> #                self._rbac_context['project_id'] = pecan.request.headers.get('X-Project-Id')
> #                self._rbac_context['user_id'] = pecan.request.headers.get('X-User-Id')
>             #return f(*args)
>             f(self, *args)
>         return inner
>     return wrapper
>  
> and here’s how it’s used:
>  
> class MetersController(rest.RestController):
>     """Works on meters."""
>  
>     _rbac_context = {}
>     @pecan.expose()
>     def _lookup(self, meter_name, *remainder):
>         return MeterController(meter_name), remainder
>  
>     @wsme_pecan.wsexpose([Meter], [Query])
>     @rbac_validate.protected('meters')
>     def get_all(self, q=None):
>         """Return all known meters, based on the data recorded so far.
>  
>         :param q: Filter rules for the meters to be returned.
>         """
>         q = q or [] …
>  
>  
> but we get errors similar to below where the arg parser cannot find the query parameter because the decorator doesn’t take a q argument as MetersController.get_all does. 
>  
> Is there any way to get a decorator to work within the v2 API code and wsme framework or should we consider another approach?  Decorators would really simplify the RBAC idea we’re working on, which is mostly code-implemented save for this fairly major problem.
>  
> I have a WIP registered BP on this at https://blueprints.launchpad.net/ceilometer/+spec/ready-ceilometer-rbac-keystone-v3.
>  
> If I can provide more details I’ll be happy to.
>  
> Thanks
> Eric
>  
>   /usr/local/bin/ceilometer-api(10)<module>()
> -> sys.exit(api())
>   /opt/stack/ceilometer/ceilometer/cli.py(96)api()
> -> srv.serve_forever()
>   /usr/lib/python2.7/SocketServer.py(227)serve_forever()
> -> self._handle_request_noblock()
>   /usr/lib/python2.7/SocketServer.py(284)_handle_request_noblock()
> -> self.process_request(request, client_address)
>   /usr/lib/python2.7/SocketServer.py(310)process_request()
> -> self.finish_request(request, client_address)
>   /usr/lib/python2.7/SocketServer.py(323)finish_request()
> -> self.RequestHandlerClass(request, client_address, self)
>   /usr/lib/python2.7/SocketServer.py(638)__init__()
> -> self.handle()
>   /usr/lib/python2.7/wsgiref/simple_server.py(124)handle()
> -> handler.run(self.server.get_app())
>   /usr/lib/python2.7/wsgiref/handlers.py(85)run()
> -> self.result = application(self.environ, self.start_response)
>   /opt/stack/python-keystoneclient/keystoneclient/middleware/auth_token.py(663)__call__()
> -> return self.app(env, start_response)
>   /opt/stack/ceilometer/ceilometer/api/app.py(97)__call__()
> -> return self.v2(environ, start_response)
>   /usr/local/lib/python2.7/dist-packages/pecan/middleware/static.py(151)__call__()
> -> return self.app(environ, start_response)
>   /usr/local/lib/python2.7/dist-packages/pecan/middleware/debug.py(289)__call__()
> -> return self.app(environ, start_response)
>   /usr/local/lib/python2.7/dist-packages/pecan/middleware/recursive.py(56)__call__()
> -> return self.application(environ, start_response)
>   /opt/stack/ceilometer/ceilometer/api/middleware.py(83)__call__()
> -> app_iter = self.app(environ, replacement_start_response)
>   /usr/local/lib/python2.7/dist-packages/pecan/core.py(750)__call__()
> -> return super(Pecan, self).__call__(environ, start_response)
>   /usr/local/lib/python2.7/dist-packages/pecan/core.py(616)__call__()
> -> self.invoke_controller(controller, args, kwargs, state)
>   /usr/local/lib/python2.7/dist-packages/pecan/core.py(526)invoke_controller()
> -> result = controller(*args, **kwargs)
>   /usr/local/lib/python2.7/dist-packages/wsmeext/pecan.py(79)callfunction()
> -> pecan.request.body, pecan.request.content_type
>   /usr/local/lib/python2.7/dist-packages/wsme/rest/args.py(276)get_args()
> -> from_args = args_from_args(funcdef, args, kwargs)
> > /usr/local/lib/python2.7/dist-packages/wsme/rest/args.py(189)args_from_args()
> -> funcdef.get_arg(argname).datatype, value
>  
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