Ceph settings: more moduler manila configuration

Add more logic to the manila configuration so that both the cephfs
and the ganesha backend can be configured. Initially configures
just one of them (cephfs by default as ganesha is not deployed
by default), even though the code should be able to deploy
multiple manila backends, once a better condition is set.

hooks/playbooks/templates/config_ceph_backends.yaml.j2

@@ -86,13 +86,27 @@ patches:
       path: /spec/manila/enabled
       value: {{ cifmw_services_manila_enabled | default('false') }}
 
+{% if cifmw_services_manila_enabled | default('false') | bool -%}
+{%   set _manila_backends = [] -%}
+{%   set _manila_protocols = [] -%}
+{# TODO: the two backends are mutually exclusive right now, #}
+{# but this condition could be rewritten to support both (or more) #}
+{# and the rest of the code is ready to support more backends #}
+{%   if cifmw_ceph_daemons_layout.ceph_nfs_enabled | default(false) | bool -%}
+{%      set _ = _manila_backends.append('nfs') %}
+{%      set _ = _manila_protocols.append('cephfsnfs') %}
+{%   else %}
+{%      set _ = _manila_backends.append('cephfs') %}
+{%      set _ = _manila_protocols.append('cephfs') %}
+{%   endif %}
     - op: add
       path: /spec/manila/template/customServiceConfig
       value: |
         [DEFAULT]
-        enabled_share_backends=cephfs
-        enabled_share_protocols=cephfs
+        enabled_share_backends={{ _manila_backends|join(',') }}
+        enabled_share_protocols={{ _manila_protocols|join(',') }}
         debug=True
+{%   if 'cephfs' in _manila_backends -%}
         [cephfs]
         driver_handles_share_servers=False
         share_backend_name=cephfs
@@ -102,3 +116,15 @@ patches:
         cephfs_cluster_name=ceph
         cephfs_volume_mode=0755
         cephfs_protocol_helper_type=CEPHFS
+{%   endif %}
+{%   if 'cephfsnfs' in _manila_backends -%}
+        [cephfsnfs]
+        driver_handles_share_servers=False
+        share_backend_name=cephfs
+        share_driver=manila.share.drivers.cephfs.driver.CephFSDriver
+        cephfs_auth_id=openstack
+        cephfs_cluster_name=ceph
+        cephfs_nfs_cluster_id=cephfs
+        cephfs_protocol_helper_type=NFS
+{%   endif %}
+{% endif %}