feat: adopt cephadm (#752)

diff --git a/playbooks/openstack.yml b/playbooks/openstack.yml
index be3cc7c..3d12749 100644
--- a/playbooks/openstack.yml
+++ b/playbooks/openstack.yml
@@ -59,6 +59,9 @@
     - role: placement
       tags:
         - placement
+  environment:
+    CEPH_CONTAINER_IMAGE: "{{ cephadm_image | default('quay.io/ceph/ceph:v' + (ceph_version | default('18.2.1'))) }}"
+    CEPH_CONTAINER_BINARY: docker
 
 - name: Configure operating system
   hosts: controllers:computes