Add cacert to .fields in HttpProxy

[damoore044]

Description of changes

Add cacert to .fields in http_proxy, which is the path within the host to the cacert for the proxy.
Supports robottelo PR# 11454

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (64ca919) 91.83% compared to head (eea3d64) 91.83%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #923   +/-   ##
=======================================
  Coverage   91.83%   91.83%           
=======================================
  Files           6        6           
  Lines        3000     3001    +1     
=======================================
+ Hits         2755     2756    +1     
  Misses        245      245           

Impacted Files	Coverage Δ
nailgun/entities.py	90.77% <100.00%> (+<0.01%)	⬆️

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[vsedmik]

IMHO you also need to add the field into the ignore list, as this field is not returned back on GET request and thus should be ignored when missing in the response:

[root@satellite ~]# curl -sku admin:changeme -H "Content-type: application/json" -X GET https://$(hostname)/api/http_proxies/1 | json_reformat
{
    "id": 1,
    "name": "AwesomeProxy",
    "url": "http://my.awesome.proxy.com:3128",
    "username": null,
    "locations": [
        {
            "id": 2,
            "name": "Default Location",
            "title": "Default Location"
        }
    ],
    "organizations": [ ]
}

just few lines lower:

if ignore is None:
    ignore = set()
ignore.add('cacert')
ignore.add('password')
...

[Griffin-Sullivan]

Yeah I think @damoore044 was about to try curl to see what is returned from the GET. For reference David, nailgun entities are designed to look for any of the attributes defined in __init__() when receiving a GET request (in this case the read function). So for this instance, we defined the cacert field in the __init__, and now when we try to run something like proxy.read() it will go through each field listed in the init and see what value was returned for that field. However, the GET request to the proxy endpoint doesn't include cacert, so when nailgun doesn't find it we get a KeyError. This situation is pretty common, especially with things like password since we don't want it to be readable. So when this happens, we have a set named ignore which we can add our key to so that nailgun knows to not look for it when we run the read.

Here's the code that implements the logic I just explained: https://github.com/SatelliteQE/nailgun/blob/master/nailgun/entity_mixins.py#L777

All you need to do is add ignore.add('cacert'), to the HTTPProxy's read method.

[jyejare]

Very nice explanation @Griffin-Sullivan !!

@damoore044 Please do it before we merge !

[jyejare]

ACK pending @vsedmik comment for ignoring the field in read.

[damoore044]

Thanks @Griffin-Sullivan for the helpful explanation, just addressed those