Merge pull request #120 from github/threshold_overrides

add ability to configure update/delete thresholds

octodns/provider/base.py

@@ -21,10 +21,14 @@ class Plan(object):
     MAX_SAFE_DELETE_PCENT = .3
     MIN_EXISTING_RECORDS = 10
 
-    def __init__(self, existing, desired, changes):
+    def __init__(self, existing, desired, changes,
+                 update_pcent_threshold=MAX_SAFE_UPDATE_PCENT,
+                 delete_pcent_threshold=MAX_SAFE_DELETE_PCENT):
         self.existing = existing
         self.desired = desired
         self.changes = changes
+        self.update_pcent_threshold = update_pcent_threshold
+        self.delete_pcent_threshold = delete_pcent_threshold
 
         change_counts = {
             'Create': 0,
@@ -55,14 +59,14 @@ class Plan(object):
             update_pcent = self.change_counts['Update'] / existing_record_count
             delete_pcent = self.change_counts['Delete'] / existing_record_count
 
-            if update_pcent > self.MAX_SAFE_UPDATE_PCENT:
+            if update_pcent > self.update_pcent_threshold:
                 raise UnsafePlan('Too many updates, {} is over {} percent'
                                  '({}/{})'.format(
                                      update_pcent,
                                      self.MAX_SAFE_UPDATE_PCENT * 100,
                                      self.change_counts['Update'],
                                      existing_record_count))
-            if delete_pcent > self.MAX_SAFE_DELETE_PCENT:
+            if delete_pcent > self.delete_pcent_threshold:
                 raise UnsafePlan('Too many deletes, {} is over {} percent'
                                  '({}/{})'.format(
                                      delete_pcent,
@@ -79,11 +83,19 @@ class Plan(object):
 
 class BaseProvider(BaseSource):
 
-    def __init__(self, id, apply_disabled=False):
+    def __init__(self, id, apply_disabled=False,
+                 update_pcent_threshold=Plan.MAX_SAFE_UPDATE_PCENT,
+                 delete_pcent_threshold=Plan.MAX_SAFE_DELETE_PCENT):
         super(BaseProvider, self).__init__(id)
-        self.log.debug('__init__: id=%s, apply_disabled=%s', id,
+        self.log.debug('__init__: id=%s, apply_disabled=%s, '
-                       apply_disabled)
+                       'update_pcent_threshold=%d, delete_pcent_threshold=%d',
+                       id,
+                       apply_disabled,
+                       update_pcent_threshold,
+                       delete_pcent_threshold)
         self.apply_disabled = apply_disabled
+        self.update_pcent_threshold = update_pcent_threshold
+        self.delete_pcent_threshold = delete_pcent_threshold
 
     def _include_change(self, change):
         '''
@@ -124,7 +136,9 @@ class BaseProvider(BaseSource):
             changes += extra
 
         if changes:
-            plan = Plan(existing, desired, changes)
+            plan = Plan(existing, desired, changes,
+                        self.update_pcent_threshold,
+                        self.delete_pcent_threshold)
             self.log.info('plan:   %s', plan)
             return plan
         self.log.info('plan:   No changes')

tests/test_octodns_provider_base.py

@@ -23,6 +23,8 @@ class HelperProvider(BaseProvider):
         self.__extra_changes = extra_changes
         self.apply_disabled = apply_disabled
         self.include_change_callback = include_change_callback
+        self.update_pcent_threshold = Plan.MAX_SAFE_UPDATE_PCENT
+        self.delete_pcent_threshold = Plan.MAX_SAFE_DELETE_PCENT
 
     def populate(self, zone, target=False, lenient=False):
         pass
@@ -288,3 +290,59 @@ class TestBaseProvider(TestCase):
                                       Plan.MAX_SAFE_DELETE_PCENT))]
 
         Plan(zone, zone, changes).raise_if_unsafe()
+
+    def test_safe_updates_min_existing_override(self):
+        safe_pcent = .4
+        # 40% + 1 fails when more
+        # than MIN_EXISTING_RECORDS exist
+        zone = Zone('unit.tests.', [])
+        record = Record.new(zone, 'a', {
+            'ttl': 30,
+            'type': 'A',
+            'value': '1.2.3.4',
+        })
+
+        for i in range(int(Plan.MIN_EXISTING_RECORDS)):
+            zone.add_record(Record.new(zone, str(i), {
+                            'ttl': 60,
+                            'type': 'A',
+                            'value': '2.3.4.5'
+                            }))
+
+        changes = [Update(record, record)
+                   for i in range(int(Plan.MIN_EXISTING_RECORDS *
+                                      safe_pcent) + 1)]
+
+        with self.assertRaises(UnsafePlan) as ctx:
+            Plan(zone, zone, changes,
+                 update_pcent_threshold=safe_pcent).raise_if_unsafe()
+
+        self.assertTrue('Too many updates' in ctx.exception.message)
+
+    def test_safe_deletes_min_existing_override(self):
+        safe_pcent = .4
+        # 40% + 1 fails when more
+        # than MIN_EXISTING_RECORDS exist
+        zone = Zone('unit.tests.', [])
+        record = Record.new(zone, 'a', {
+            'ttl': 30,
+            'type': 'A',
+            'value': '1.2.3.4',
+        })
+
+        for i in range(int(Plan.MIN_EXISTING_RECORDS)):
+            zone.add_record(Record.new(zone, str(i), {
+                            'ttl': 60,
+                            'type': 'A',
+                            'value': '2.3.4.5'
+                            }))
+
+        changes = [Delete(record)
+                   for i in range(int(Plan.MIN_EXISTING_RECORDS *
+                                      safe_pcent) + 1)]
+
+        with self.assertRaises(UnsafePlan) as ctx:
+            Plan(zone, zone, changes,
+                 delete_pcent_threshold=safe_pcent).raise_if_unsafe()
+
+        self.assertTrue('Too many deletes' in ctx.exception.message)