+++ This bug was initially created as a clone of Bug #1558114 +++

Description of problem:

We need a way to retrieve the total # of pools for an owner to support paging of upstream/portal subscriptions in the UI. Retrieving the total # by way of minimizing includes is not sufficient (too slow).

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
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Actual results:

No such API exists

Expected results:

There exists an API: GET /owners/{owner_key}/pools/count which returns the total number of pools which respects the current filtering 


Additional info: GET /owners/:owner_id/consumers/count is a similar API that already exists

IT will need the version containing this API to support our work

--- Additional comment from Barnaby Court on 2018-03-19 13:43:41 EDT ---

After discussions with Brad, it would be acceptable to provide the maximum number of records as metadata when the first page of data is returned.

--- Additional comment from Barnaby Court on 2018-03-22 10:55:17 EDT ---

Currently we provide a link header that does have some useful information and could be used as a workaround. However, it would be better to include the total # of items as a value. 

Link: <https://localhost:8443/candlepin/owners/foo/pools?include=id&page=1&per_page=5&include=id&per_page=5&page=2>; rel="next", <https://localhost:8443/candlepin/owners/foo/pools?include=id&page=1&per_page=5&include=id&per_page=5&page=1>; rel="first", <https://localhost:8443/candlepin/owners/foo/pools?include=id&page=1&per_page=5&include=id&per_page=5&page=200>; rel="last"

--- Additional comment from Barnaby Court on 2018-03-22 10:59:59 EDT ---

A http header of "X-total-count" with the total number of records would be very helpful if paging is used.

--- Additional comment from Jonathon Turel on 2018-03-23 10:27:24 EDT ---

I looked into using the link header. My approach was using ?page=1&per_page=1 in my query. In theory the last page should be the total number. It was still slow enough to make paging an unpleasant experience when there are many pools. I had about 3k pool and the response was over 3 seconds, so we won't be going that route as a workaround.

In addition to the "x-total-count" header, it will be nice to have an "x-subtotal-count" header which reflects the number of results according to any filtering applied.

--- Additional comment from Jonathon Turel on 2018-03-23 13:51:24 EDT ---

Barnaby,

Per our in-person chat I spoke with Walden regarding handling subtotals. He told me that the x-total-count header reflecting the total after filtering applied is fine - so we can forget about adding the subtotal header I proposed.