[tripleo][ansible] ensure python dependencies on hosts for modules/plugins
Since most of tripleo-ansible modules do 'import foobar', we should
ensure that we have the corresponding python packages installed on
target hosts. Some of them, like python3-dmidecode may be in base
Centos8 images. But some may not, especially for custom deployed-servers
provided by users for deployments.
Those packages must be tracked and ensured to be installed by tripleo
(preferred), or validated deploy-time (nah...), or at least documented
as the modules get created or changed by devs.
That also applies to adding action plugins' deps for
python-tripleoclient or tripleo-ansible perhaps.
Shall we write a spec for that or just address that as a bug ?