[HorizonXP]

I want to chime in with my experience.

Our service is built on top of docker deployed on CoreOS with fleet and etcd. Most of our secrets & runtime configuration was stored in etcd, which was our attempt to store the config in the environment (http://12factor.net/config).

With Kubernetes, life is much simpler. Gone are the silly fleet configuration files, and the bootstrap scripts I used to configure etcd. Moreover, Kubernetes' secrets volume means I can have my configuration and secrets easily plugged in.

There are definitely other great solutions out there, but I'm sold on Kubernetes.