--limit can collide with query string on some commands

[Chris Dent]

Using the new 1.5.0 there is some inconsisten behavior on some commands when trying to (naively) mix the use of the --limit command with a limit query. Some examples:

* ceilometer event-list --limit=1 # returns one item
* ceilometer event-list -q limit=1 # returns an empty list

* ceilometer resource-list --limit=1 # returns one item
* ceilometer resource-list -q limit=1 # errors as follows

  get_resources() got multiple values for keyword argument 'limit' (HTTP 500) (Request-ID: req-79132b9a-505e-4a92-bd86-b094f455ee53)

* ceilometer meter-list --limit =1 # returns one item
* ceilometer meter-list -q limit=1 # errors the same way as resource-list

* ceilometer sample-list --limit =1 # returns one item
* ceilometer sample-list -q limit=1 # errors as follows

  Unknown argument: "limit": unrecognized field in query: [<Query u'limit' eq u'1' >], valid keys: ['message_id', 'meter', 'project', 'resource', 'search_offset', 'source', 'timestamp', 'user'] (HTTP 400) (Request-ID: req-9feebef4-3e38-4ed9-91ea-09a005f1733d)

There seem to be at least two bugs here:

* the client is not constructing the right query based on its input, or at least producing an error locally before going to the server
* the server is producing a 500 when it should be producing a 400 when it gets multiple limits

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/222169

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/222169
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=05f7ad3f8b65135381ffbb2fab5ed67487c05778
Submitter: Jenkins
Branch: master

commit 05f7ad3f8b65135381ffbb2fab5ed67487c05778
Author: Chris Dent <email address hidden>
Date: Thu Sep 10 12:36:56 2015 +0000

    Avoid 500 errors when duplicating limit queries

    If get_meters() or get_resources() gets >1 limit keyword arguments
    (due to query string processing) they cause a TypeError which
    reaches the user as 500 response code. This is no good, it should be
    a 400.

    Change-Id: I4621aa9c6d35f1545b75443983ba20845a85e170
    Closes-Bug: #1494245

[Rohit Jaiswal (rohit-jaiswal-3)]

Not sure if this affects ceilometerclient unless we want to pre-validate this in client before invoking the api. For all 3 - meters, samples and resources, using limit with -q leads to HTTP 400 error from the ceilometer-api, which means client does not validate anything.