This code empirically doesn't work. It's not entirely clear why, even
having done quite a bit of debugging; partly because the code is quite
convoluted, and because it shows the symptoms of people making changes
over time without really understanding how it was supposed to work.
Moreover, this code targets an old version of the APNs provider API.
Apple deprecated that in 2015, in favor of a shiny new one which uses
HTTP/2 to meet the same needs for concurrency and scale that the old
one had to do a bunch of ad-hoc protocol design for.
So, rip this code out. We'll build a pathway to the new API from
scratch; it's not that complicated.
This allows the actual nagios work involved with
check_send_receive_time nagios checks to be done by an unprivileged
"nagios" user rather than the "zulip" user.
The old "zulip_internal" name was from back when Zulip, Inc. had two
distributions of Zulip, the enterprise distribution in puppet/zulip/
and the "internal" SAAS distribution in puppet/zulip_internal. I
think the name is a bit confusing in the new fully open-source Zulip
work, so we're replacing it with "zulip_ops". I don't think the new
name is perfect, but it's better.
In the following commits, we'll delete a bunch of pieces of Zulip,
Inc.'s infrastructure that don't exist anymore and thus are no longer
useful (e.g. the old Trac configuration), with the goal of cleaning
the repository of as much unnecessary content as possible.