As of version 4, ceph-ansible ships it's own filter_plugins [1]
so we need to include them in the environment when tripleo
executes ceph-ansible.
This change is going directly into Stein becauase the relevant
code was moved from tripleo-heat-templates to tripleo-ansible
during Train. The same change has already been proposed in Master
and Train (64f6d3ba1979e21fdf5392a056c13f313220be3e) in tripleo-
ansible.
Change-Id: I434273b4fee2719eb6ea9f4392364644446f11e6
Closes-Bug: #1852136
fc5ca307bd