From d6deabcc522f8a18cfdef39acf0c02abc377f818 Mon Sep 17 00:00:00 2001
From: Viranch Mehta <email@viranch.me>
Date: Fri, 25 Jun 2021 10:52:35 -0700
Subject: [PATCH] Fix duplicate endpoints in Azure DNS dynamic records

---
 octodns/provider/azuredns.py            | 11 +++++-
 tests/test_octodns_provider_azuredns.py | 45 +++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/octodns/provider/azuredns.py b/octodns/provider/azuredns.py
index 4551c6c..c69c723 100644
--- a/octodns/provider/azuredns.py
+++ b/octodns/provider/azuredns.py
@@ -922,6 +922,16 @@ class AzureProvider(BaseProvider):
 
             for profile in profiles:
                 name = profile.name
+
+                endpoints = set()
+                for ep in profile.endpoints:
+                    if not ep.target:
+                        continue
+                    if ep.target in endpoints:
+                        msg = '{} contains duplicate endpoint {}'
+                        raise AzureException(msg.format(name, ep.target))
+                    endpoints.add(ep.target)
+
                 if name in seen_profiles:
                     # exit if a possible collision is detected, even though
                     # we've tried to ensure unique mapping
@@ -1053,7 +1063,6 @@ class AzureProvider(BaseProvider):
 
             while pool_name:
                 # iterate until we reach end of fallback chain
-                default_seen = False
                 pool = pools[pool_name].data
                 if len(pool['values']) > 1:
                     # create Weighted profile for multi-value pool
diff --git a/tests/test_octodns_provider_azuredns.py b/tests/test_octodns_provider_azuredns.py
index eb74007..13c1bf4 100644
--- a/tests/test_octodns_provider_azuredns.py
+++ b/tests/test_octodns_provider_azuredns.py
@@ -999,6 +999,51 @@ class TestAzureDnsProvider(TestCase):
                 'Collision in Traffic Manager'
             ))
 
+    @patch(
+        'octodns.provider.azuredns.AzureProvider._generate_traffic_managers')
+    def test_extra_changes_non_last_fallback_contains_default(self, mock_gtm):
+        provider = self._get_provider()
+
+        desired = Zone(zone.name, sub_zones=[])
+        record = Record.new(desired, 'foo', {
+            'type': 'CNAME',
+            'ttl': 60,
+            'value': 'default.unit.tests.',
+            'dynamic': {
+                'pools': {
+                    'one': {
+                        'values': [{'value': 'one.unit.tests.'}],
+                        'fallback': 'def',
+                    },
+                    'def': {
+                        'values': [{'value': 'default.unit.tests.'}],
+                        'fallback': 'two',
+                    },
+                    'two': {
+                        'values': [{'value': 'two.unit.tests.'}],
+                    },
+                },
+                'rules': [
+                    {'pool': 'one'},
+                ]
+            }
+        })
+        desired.add_record(record)
+        changes = [Create(record)]
+
+        # assert that no exception is raised
+        provider._extra_changes(zone, desired, changes)
+
+        # simulate duplicate endpoint and assert exception
+        endpoint = Endpoint(target='dup.unit.tests.')
+        mock_gtm.return_value = [Profile(
+            name='test-profile',
+            endpoints=[endpoint, endpoint],
+        )]
+        with self.assertRaises(AzureException) as ctx:
+            provider._extra_changes(zone, desired, changes)
+            self.assertTrue('duplicate endpoint' in text_type(ctx))
+
     def test_extra_changes_invalid_dynamic_A(self):
         provider = self._get_provider()