Best practice to keep my droplet up-to-date?
I've got 6 Ubuntu droplets, but I only ssh into two of them regularly to do code pulls. On those two droplets, I often see that I've got updates available, so I run a quick apt-get update && apt-get upgrade && apt-get dist-upgrade, and I get on with my work. But my other droplets aren't serviced as often, until this week, one I hadn't updated since the day POODLE broke out.
My question is this: what's the best way to keep my droplets up-to-date without manual oversight?
My first thought was to run a daily cronjob. Is that a bad idea?