Recently a user, using the admin panel, triggered a Craft CMS update. I would like to determine which user it was. Is there any log of these actions where I can check for this? If it's in craft/storage/runtime/logs/craft.log, can you please tell me what to search for?
That one is tricky.
I can't think of anything that gets logged in Craft's log files currently that would help determine that.
We do keep track of the request IP address in all of our web service logs, so if you wanted to send the domain along with the approximate update time to email@example.com, we could at least send over the IP address the update was triggered from. That won't help much if the person was sitting behind a proxy/DHCP server, though.