Validate that MX preference parses as int

octodns/record.py

@@ -424,8 +424,14 @@ class MxValue(object):
     @classmethod
     def _validate_value(cls, value):
         reasons = []
-        if 'preference' not in value and 'priority' not in value:
+        try:
+            # seperate lines to have preference set in the ValueError case
+            preference = value.get('preference', None) or value['priority']
+            int(preference)
+        except KeyError:
             reasons.append('missing preference')
+        except ValueError:
+            reasons.append('invalid preference "{}"'.format(preference))
         exchange = None
         try:
             exchange = value.get('exchange', None) or value['value']

tests/test_octodns_record.py

@@ -898,7 +898,7 @@ class TestRecordValidation(TestCase):
             }
         })
 
-        # missing priority
+        # missing preference
         with self.assertRaises(ValidationError) as ctx:
             Record.new(self.zone, '', {
                 'type': 'MX',
@@ -909,7 +909,19 @@ class TestRecordValidation(TestCase):
             })
         self.assertEquals(['missing preference'], ctx.exception.reasons)
 
-        # missing value
+        # invalid preference
+        with self.assertRaises(ValidationError) as ctx:
+            Record.new(self.zone, '', {
+                'type': 'MX',
+                'ttl': 600,
+                'value': {
+                    'preference': 'nope',
+                    'exchange': 'foo.bar.com.'
+                }
+            })
+        self.assertEquals(['invalid preference "nope"'], ctx.exception.reasons)
+
+        # missing exchange
         with self.assertRaises(ValidationError) as ctx:
             Record.new(self.zone, '', {
                 'type': 'MX',