[CentOS] Where can CentOS7 yum-cron logs be found?

Mon Aug 17 08:49:32 UTC 2020
Gunnar Niels <gunnar.s.niels at gmail.com>

I'm trying to setup two CentOS7 systems with automatic security updates to run
as my kubernetes nodes. I've also centralized all my outgoing mail through my
mailgun service, so I've been using the cli tool "mailx", which I have configured
with my credentials. Coming from Fedora32 and CentOS7, dnf-automatic had a
helpful emission target that was "email_command". By default it sent notifications
using this command. With yum-cron, all I see is "email", which doesn't appear
to use the "mail" command.

I would like to set up something myself to send the daily yum activity, but it's
not clear at all where I should expect the yum-cron "stdio" output to end up at.
I "started" the service, which is really just creates sentincal file to allow
the yum.daily cron entry to run. However, when I look at /var/log/yum, there's
nothing there of interest. I can see that it claims to have run, but I have no
idea what it did.

Is there another place I should be looking for what this actually did?

Separately, I'm looking for a way to confirm its behavior. I was able to do this
on my dnf systems by downgrading a package, but if I use `yum downgrade X` on
this CentOS7 system...it just reports success and does nothing. Any ideas about
that one?