add status set to blocked for no v6 addr rxed from storage rel

hooks/swift_hooks.py

@@ -214,6 +214,7 @@ def storage_changed():
                    "(got=%s)" % (addr))
             log(msg, level=WARNING)
             host_ip = addr
+            return
     else:
         host_ip = openstack.get_host_ip(addr)
 

lib/swift_utils.py

@@ -60,6 +60,7 @@ from charmhelpers.core.host import (
 from charmhelpers.contrib.network.ip import (
     format_ipv6_addr,
     get_ipv6_addr,
+    is_ipv6,
 )
 from charmhelpers.core.decorators import (
     retry_on_exception,
@@ -1057,6 +1058,16 @@ def assess_status(configs):
         status_set('blocked', 'Not enough storage zones for minimum replicas')
         return
 
+    if config('prefer-ipv6'):
+        for rid in relation_ids('swift-storage'):
+            for unit in related_units(rid):
+                addr = relation_get(attribute='private-address', unit=unit,
+                                    rid=rid)
+                if not is_ipv6(addr):
+                    status_set('blocked', 'Did not get IPv6 address from '
+                               'storage relation (got=%s)' % (addr))
+                    return
+
     if relation_ids('identity-service'):
         required_interfaces['identity'] = ['identity-service']