COST-2654: Only collect distinct tags from db. (project-koku#3666)

* COST-2654: Only collect distinct tags from db.

* Fix mocked django values for tests.

koku/api/query_params.py

@@ -111,7 +111,7 @@ def __str__(self):
     def _get_tag_keys(self, model):
         """Get a list of tag keys to validate filters."""
         with tenant_context(self.tenant):
-            tags = model.objects.values("key")
+            tags = model.objects.values("key").distinct()
             tag_list = [":".join(["tag", tag.get("key")]) for tag in tags]
             tag_list.extend([":".join(["and:tag", tag.get("key")]) for tag in tags])
             tag_list.extend([":".join(["or:tag", tag.get("key")]) for tag in tags])

koku/api/report/test/test_queries.py

@@ -198,20 +198,19 @@ class ReportQueryHandlerTest(IamTestCase):
     def setUp(self):
         """Test setup."""
         self.mock_tag_key = FAKE.word()
+        tag_mock = Mock()
+        tag_mock.objects.values.return_value.distinct.return_value = [
+            {"key": self.mock_tag_key, "values": [FAKE.word(), FAKE.word()]}
+        ]
+
         self.mock_view = Mock(
             spec=ReportView,
             report="mock",
             permission_classes=[Mock],
             provider="mock",
             serializer=Mock,
             query_handler=Mock,
-            tag_handler=[
-                Mock(
-                    objects=Mock(
-                        values=Mock(return_value=[{"key": self.mock_tag_key, "values": [FAKE.word(), FAKE.word()]}])
-                    )
-                )
-            ],
+            tag_handler=[tag_mock],
         )
 
     def test_init(self):

koku/api/test_query_params.py

@@ -87,13 +87,11 @@ def test_constructor(self):
         This test is a bit fatter than it needs to be to help show how to mock
         out the Request and View objects.
         """
-
-        def fake_tags():
-            fake_tags = []
-            for _ in range(0, random.randint(2, 10)):
-                fake_tags.append({"key": self.FAKE.word(), "value": self.FAKE.word()})
-            return fake_tags
-
+        tag_keys = ["app", "az", "environment", "cost_center", "fake", "other", "this"]
+        fake_objects = Mock()
+        fake_objects.objects.values.return_value.distinct.return_value = [
+            {"key": key, "value": self.FAKE.word()} for key in tag_keys
+        ]
         fake_request = Mock(
             spec=HttpRequest,
             user=Mock(access=Mock(get=lambda key, default: default), customer=Mock(schema_name="acct10001")),
@@ -105,10 +103,7 @@ def fake_tags():
             query_handler=Mock(provider=random.choice(PROVIDERS)),
             report=self.FAKE.word(),
             serializer=Mock,
-            tag_handler=[
-                Mock(objects=Mock(values=lambda _: fake_tags())),
-                Mock(objects=Mock(values=lambda _: fake_tags())),
-            ],
+            tag_handler=[fake_objects, fake_objects],
         )
         self.assertIsInstance(QueryParameters(fake_request, fake_view), QueryParameters)
 
@@ -647,14 +642,17 @@ def test_process_tag_query_params(self):
             user=Mock(access=Mock(get=lambda key, default: default), customer=Mock(schema_name="acct10001")),
             GET=Mock(urlencode=Mock(return_value=fake_uri)),
         )
-        fake_objects = Mock(values=lambda _: [{"key": key, "value": self.FAKE.word()} for key in tag_keys])
+        fake_objects = Mock()
+        fake_objects.objects.values.return_value.distinct.return_value = [
+            {"key": key, "value": self.FAKE.word()} for key in tag_keys
+        ]
         fake_view = Mock(
             spec=ReportView,
             provider=self.FAKE.word(),
             query_handler=Mock(provider=random.choice(PROVIDERS)),
             report=self.FAKE.word(),
             serializer=Mock,
-            tag_handler=[Mock(objects=fake_objects)],
+            tag_handler=[fake_objects],
         )
         params = QueryParameters(fake_request, fake_view)
         self.assertEqual(params.tag_keys, expected)