set private/public addr like in ceph charm

hooks/hooks.py

@@ -46,7 +46,8 @@ from utils import (
 
 from charmhelpers.contrib.openstack.alternatives import install_alternative
 from charmhelpers.contrib.network.ip import (
-    is_ipv6
+    is_ipv6,
+    get_ipv6_addr
 )
 
 hooks = Hooks()
@@ -86,6 +87,13 @@ def emit_cephconf():
         'ceph_cluster_network': config('ceph-cluster-network'),
     }
 
+    if config('prefer-ipv6'):
+        dynamic_ipv6_address = get_ipv6_addr()[0]
+        if not config('ceph-public-network'):
+            cephcontext['public_addr'] = dynamic_ipv6_address
+        if not config('ceph-cluster-network'):
+            cephcontext['cluster_addr'] = dynamic_ipv6_address
+
     # Install ceph.conf as an alternative to support
     # co-existence with other charms that write this file
     charm_ceph_conf = "/var/lib/charm/{}/ceph.conf".format(service_name())

templates/ceph.conf

@@ -21,6 +21,14 @@
  cluster network = {{ ceph_cluster_network }}
 {%- endif %}
 
+{% if public_addr %}
+public addr = {{ public_addr }}
+{% endif %}
+{% if cluster_addr %}
+cluster addr = {{ cluster_addr }}
+{%- endif %}
+
+
 [mon]
  keyring = /var/lib/ceph/mon/$cluster-$id/keyring