Description of problem:
When site-docker.yml and add-mon.yml playbooks were initiated playbooks failed saying monitor container not found
It appeared that the playbook is expecting all mon containers on monitor node present in https://github.com/ceph/ceph-ansible/blob/stable-4.0/roles/ceph-handler/tasks/handler_osds.yml#L6-L10

Version-Release number of selected component (if applicable):
# rpm -qa|grep ceph-ansible
ceph-ansible-4.0.10-1.el7cp.noarch


How reproducible:
Always (2/2)

Steps to Reproduce:
1. configure containerized 4.x cluster

Actual results:
Playbook is failing looking for containers in inappropriate nodes

Expected results:
Playbooks must not fail

Additional info:

Workaround : Ignore errors and Restart site-docker if needed

Target release has been set tentatively based on impact on usability criteria, please feel free to re-target if its inappropriately