fixed get_mon_hosts()

hooks/hooks.py

@@ -41,6 +41,7 @@ from charmhelpers.fetch import (
 
 from utils import (
     render_template,
+    get_host_ip,
     setup_ipv6
 )
 
@@ -143,9 +144,10 @@ def get_mon_hosts():
         for unit in related_units(relid):
             if config('prefer-ipv6'):
                 addr = relation_get('ceph-public-address', unit, relid) or \
-                    get_ipv6_addr()
+                    relation_get('private-address', unit, relid)
             else:
-                addr = relation_get('private-address', unit, relid)
+                addr = relation_get('ceph-public-address', unit, relid) or \
+                    get_host_ip(relation_get('private-address', unit, relid))
 
             if addr is not None:
                 if is_ipv6(addr):

hooks/utils.py

@@ -10,6 +10,7 @@
 import socket
 import re
 from charmhelpers.core.hookenv import (
+    unit_get,
     cached
 )
 from charmhelpers.fetch import (
@@ -30,6 +31,13 @@ except ImportError:
                 fatal=True)
     import jinja2
 
+try:
+    import dns.resolver
+except ImportError:
+    apt_install(filter_installed_packages(['python-dnspython']),
+                fatal=True)
+    import dns.resolver
+
 
 def render_template(template_name, context, template_dir=TEMPLATES_DIR):
     templates = jinja2.Environment(
@@ -55,6 +63,21 @@ def get_unit_hostname():
     return socket.gethostname()
 
 
+@cached
+def get_host_ip(hostname=None):
+    hostname = hostname or unit_get('private-address')
+    try:
+        # Test to see if already an IPv4 address
+        socket.inet_aton(hostname)
+        return hostname
+    except socket.error:
+        # This may throw an NXDOMAIN exception; in which case
+        # things are badly broken so just let it kill the hook
+        answers = dns.resolver.query(hostname, 'A')
+        if answers:
+            return answers[0].address
+
+
 def setup_ipv6():
     ubuntu_rel = float(lsb_release()['DISTRIB_RELEASE'])
     if ubuntu_rel < 14.04: