What do you use to monitor your NON-SWARM Docker machine?

We have a machine running some stuff on Docker, and little by little it has started to become important to keep an eye on it. However, looking for information on monitoring a Docker server it always seem to assume you're running it in Swarm mode, which is not and WILL NOT be the case of this machine, Swarm adds a layer of complexity unneeded in this case.

What do you recommend for this case? I for one would love if the thing didn't just give you a view of the things running on it but also gave you notifications if something went wrong (like if a container had to be restarted, or if one suddenly started eating all the CPU or something unusual).