At the moment our dynamic_inventory does have assumption that group names
defined in env.d will not contain underscores, except when it's ending
with `_hosts` or `_containers` since inventory script uses split on `_` and taking
the last argument. So in cases when underscore was used elsewhere in the
group name it will result in unexpected behaviour.
Instead of this approach we now use regexp which replaces the last octet separated with underscore with intended suffix to preserve
rest behaviour.
Change-Id: Id9ba56292972b8b52b4786c78684f2d6f289d88a
8d46ed8842