I'm not saying that OpenStack is better/worse - it was only out of our goals. For sure OpenStack has better tenancy support, much more mature approach to networking or storage (in containers world we are still working on https://github.com/container-storage-interface/spec ) but in the same time - we only needed to have a qcow2 based vm running between already deployed pods, with the same user interface. That's all, without other story around that.