Ability to control the number of hosts returned per page

[tchellomello]

Ability to control the number of hosts returned per page which can be definitely useful some users.

Result on Foreman:

192.168.169.112 - - [03/Jul/2020:18:00:37 -0400] "GET //api/v2/hosts/3?page=1&per_page=500 HTTP/1.1" 200 2814 "-" "python-requests/2.24.0"
192.168.169.112 - - [03/Jul/2020:18:00:37 -0400] "GET //api/v2/hosts/3?page=1&per_page=500 HTTP/1.1" 200 2814 "-" "python-requests/2.24.0"
192.168.169.112 - - [03/Jul/2020:18:00:38 -0400] "GET //api/v2/hosts/2?page=1&per_page=500 HTTP/1.1" 200 2821 "-" "python-requests/2.24.0"
192.168.169.112 - - [03/Jul/2020:18:00:38 -0400] "GET //api/v2/hosts/2?page=1&per_page=500 HTTP/1.1" 200 2821 "-" "python-requests/2.24.0"
192.168.169.112 - - [03/Jul/2020:18:00:38 -0400] "GET //api/v2/hosts/5?page=1&per_page=500 HTTP/1.1" 200 2796 "-" "python-requests/2.24.0"

[mdellweg]

You could introduce a "total limit" parameter here.
But in order to get all the hosts for the inventory, you'd need to cycle through the pagination (the code already seems to do that, so i do not see the what kind of user visible difference your patch introduces).

[evgeni]

@mdellweg the code does fetch all hosts:

foreman-ansible-modules/plugins/inventory/foreman.py

Lines 176 to 177 in 8ebda3f

	# get next page
	params['page'] += 1

This is just controlling how big the individual batches are.

[tchellomello]

You could introduce a "total limit" parameter here.
But in order to get all the hosts for the inventory, you'd need to cycle through the pagination (the code already seems to do that, so i do not see the what kind of user visible difference your patch introduces).

The code does get all hosts, but for large environments, increasing the number of hosts minimizes the number of requests sent to the Foreman server. I'm going to send another PR with the max_hosts parameters so the users can limit the number of hosts returned as well.

[mdellweg]

The batch_size @evgeni proposed might be a performance thing. So it would be interesting to get some numbers on that.