cinder feature volume_copy_bps_limit needs package libcgroup

kolla version: 9.0.1
Node OS: CentOS 7
kolla_base_distro: CentOS
openstack_release: train
kolla_install_type: source

To limit the bandwith/disk pressure of volume migrations you can make use of cinder's rate limiting feature. It is described here: https://docs.openstack.org/cinder/latest/admin/blockstorage-ratelimit-volume-copy-bandwidth.html

The documentation also says that you need to have a package installed whose name is dependent on the OS:
> This feature requires libcgroup to set up blkio cgroup for disk I/O bandwidth limit. The libcgroup is provided by the cgroup-bin package in Debian and Ubuntu, or by the libcgroup-tools package in Fedora, Red Hat Enterprise Linux, CentOS, openSUSE, and SUSE Linux Enterprise.

Is there a generic way to make kolla-ansible add packages to certain containers or is there a deploy/reconfigure hook that I could use as workaround to add such customizations?

When I activate this config flag without having this package installed, volume scheduling breaks and the following stacktrace appears in the cinder-volume.log:

Traceback (most recent call last):
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_service/service.py", line 810, in run_service
    service.start()
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/service.py", line 229, in start
    service_id=Service.service_id)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/volume/manager.py", line 444, in init_host
    self._init_host(added_to_cluster, **kwargs)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/volume/manager.py", line 558, in _init_host
    self.driver.set_throttle()
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/volume/driver.py", line 551, in set_throttle
    cgroup_name)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/cinder/volume/throttling.py", line 69, in __init__
    cinder.privsep.cgroup.cgroup_create(self.cgroup)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_privsep/priv_context.py", line 245, in _wrap
    return self.channel.remote_call(name, args, kwargs)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/oslo_privsep/daemon.py", line 204, in remote_call
    raise exc_type(*result[2])
OSError: [Errno 2] No such file or directory