[gnuoy,r=hopem]

Allow corosync.conf netmtu to be set regardless of inet
mode (ipv4/ipv6).

config.yaml

@@ -71,8 +71,11 @@ options:
      and a time factor, e.g. 5s = 5 seconds. 2m = 2 minutes.
   netmtu:
     type: int
-    default: 1500
-    description: MTU size corosync used for communication.
+    default:
+    description: |
+      Specifies the corosync.conf network mtu. If unset, the default
+      corosync.conf value is used (currently 1500). See 'man corosync.conf' for
+      detailed information on this config option.
   prefer-ipv6:
     type: boolean
     default: False

hooks/hooks.py

@@ -136,6 +136,10 @@ def get_corosync_conf():
         return conf
 
     conf = {}
+
+    if config('netmtu'):
+        conf['netmtu'] = config('netmtu')
+
     for relid in relation_ids('ha'):
         for unit in related_units(relid):
             bindiface = relation_get('corosync_bindiface',
@@ -153,8 +157,6 @@ def get_corosync_conf():
 
             if config('prefer-ipv6'):
                 conf['nodeid'] = get_corosync_id(local_unit())
-                conf['netmtu'] = config('netmtu')
-
             if None not in conf.itervalues():
                 return conf
     missing = [k for k, v in conf.iteritems() if v is None]