Hello,
I am deploying Openstack with juju and maas and so far from my experience I know that by using simple KVM on nova-compute nodes performance is much slower than using docker inside nova-compute nodes. It used to be a novadocker driver to use docker properly on compute nodes (https://wiki.openstack.org/wiki/Docker). Now project is not longer maintained, but I still need nova-docker for my compute nodes. Is there any solution for this?