https://github.com/Yelp/docker-custodian looks awesome, thanks for the tip! Rancher looks great too -- would love to know if you looked at other options (kubernetes etc.) & how Rancher won out
I looked at Kubernetes before Rancher but it was hard for me to really understand where to start and how it all fit together. Now that I understand much better what I am doing I should probably take another look at it.
Rancher itself is not an alternative to Kubernetes. It can control a Kubernetes, AWS, Mesos or very simple Cattle cluster. We started with Cattle with a plan to one day use something like Kubernetes, a step at a time, because we kinda felt intimidated (I left that company) by articles like these.