loadbalancer/rackspace/list_balancers: add params

[raittes]

Load Balancer / Rackspace: allow params on listing load balancers

Description

Allow to set params to be submitted in the query string to API request.
By default, Rackspace API return a maximum of 100 items at a time.
This change allow to set "offset" in the params, to paginate requests.
Ex. list_balancers(ex_params={'offset': 100})

Status

• done, ready for review

Checklist

• Code linting
• Documentation
• Tests

[tonybaloney]

thanks for the contribution @raittes - libcloud convention is that any arguments which are not present in the base class methods are prepending with ex_.
Please could you rename the parameter to ex_params.

Ideally, there would be named keyword arguments for typical arguments, according to the docs https://developer.rackspace.com/docs/cloud-load-balancers/v1/developer-guide/#list-load-balancers they would include status, nodeaddress and changes-since.
With a simple dictionary param, it's leaving it to the developer consuming to have to read the API documentation.

[raittes]

Hi @tonybaloney, I've updated the PR, please check it out!
I've included the params for /loadbalancers, but also keep the ex_params, to allow setting general api params like limit and offset.
Thx!

[raittes]

@tonybaloney, something is missing?

[tonybaloney]

dict.iteritems() is not valid in Python 3, you must use items().

Which probably highlights that this code doesn't have a supporting unit test as TravisCI should have picked that up. please can you add a test.

[raittes]

Fixed!

Tests are ok, I forced push and TravisCI may have missed something.
Here another build: https://travis-ci.org/raittes/libcloud/jobs/140894397

======================================================================
ERROR: test_destroy_balancer (libcloud.test.loadbalancer.test_rackspace.RackspaceLBTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/raittes/projects/raittes/libcloud/libcloud/test/loadbalancer/test_rackspace.py", line 187, in test_destroy_balancer
    balancer = self.driver.list_balancers()[0]
  File "/home/raittes/projects/raittes/libcloud/libcloud/loadbalancer/drivers/rackspace.py", line 385, in list_balancers
    for key, value in ex_params.iteritems():
AttributeError: 'dict' object has no attribute 'iteritems'

[tonybaloney]

the commit came in after your comment, but the build passed now that the py3 compatibility issue was fixed up