get_pagination_params's behaviour contradicts docstring

[Artom Lifshitz]

get_pagination_params's [1] docstring states that "If 'limit' is not specified, 0, or > max_limit, we default to max_limit." In practice, the code only sets params['limit'] if 'limit' is present in the GET request. It appears as though get_pagination_params should be a private method, and get_limit_and_marker [2] should be used instead.

An effect of this mixup can be observed by setting osapi_max_limit to 1 and listing images and flavors.

Images calls get_pagination_params directly [3]. The call ignores osapi_max_limit=1 and returns all the images [attachment].

Flavors calls get_limit_and_marker [4]. The call correctly returns a single flavor with a link to the following one [attachment].

[1] https://github.com/openstack/nova/blob/master/nova/api/openstack/common.py#L196
[2] https://github.com/openstack/nova/blob/master/nova/api/openstack/common.py#L273
[3] https://github.com/openstack/nova/blob/master/nova/api/openstack/compute/images.py#L119
[4] https://github.com/openstack/nova/blob/master/nova/api/openstack/compute/plugins/v3/flavors.py#L81

[John Garbutt (johngarbutt)]

https://review.openstack.org/#/c/179947/

[John Garbutt (johngarbutt)]

This is a bit back to front I think, we could consider ensuring the nova images API respects osapi_max_limit, but we should not be updating the API to match a doc string.

[Artom Lifshitz (notartom)]

I admit I wrote the bug report backwards - it came about as I was working on other stuff, so in my mind it was structured as code first, behaviour after. I'm going to submit a duplicate report (in order to avoid cluttering this one) with a proper "this is the behaviour that's wrong" description.