tree d1802bfb69c2a8051e3fc5362b30fb70ba86bb0e
parent ad75393a990e0bd6cfa694d554b43136216db03b
author Felipe Monteiro <felipe.monteiro@att.com> 1498075507 +0100
committer Felipe Monteiro <felipe.monteiro@att.com> 1504229855 +0100

Add compare header version function to tempest.lib

The motivation for this commit is that some API responses like
backing up a server image return the location of the image_id
in either the response body or the response header depending
on the microversion, e.g. [0]. In the case of server backup
action, image_id is added to response body in microversion 2.45.

Add `compare_version_header_to_request` to
`api_version_utils` to accept a new kwarg called
`operation`. At run time, 'eq' is translated
to the __eq__ attribute of `APIVersionRequest`.
The other operations include le, lt, gt, ge, and ne.

This makes it possible to do for example:

    if api_version_utils.compare_version_header_to_response(
            "X-OpenStack-Nova-API-Version", "2.45", resp, "lt"):
        image1_id = resp['image_id']
    else:
        image1_id = data_utils.parse_image_id(resp['location'])

Which means that if "2.45" < "microversion in resp" then
we can grab the image_id from the response body -- else we have
to grab it from resp.response['location'].

This commit:
  - adds compare_version_header_to_response to api_version_utils
    allowing to compare the request's header microversion
    to an expected microversion
  - modifies test_server_actions to use the new function in tests that
    always assume that the image_id attribute is in the resp header
    (not true across all microversions) -- this can be done to other
    tests in follow-up patch
  - adds related unit tests for all scenarios

[0] https://developer.openstack.org/api-ref/compute/#create-server-back-up-createbackup-action

Change-Id: Ib97e65cca468a09bbeaf68fcfe0e8192674a481e