Replace tz.UTC with dateutil.tz.tzutc()

As discussed in https://review.opendev.org/#/c/742477/, this patch
replaces the use of `tz.UTC` with `dateutil.tz.tzutc()`

Also add python-dateutil to requirements.txt, using the same minimum
version as several other OpenStack projects, including nova.

Change-Id: I4da9e8854a571058e48c2f51c1d340bc135cfe2b

cloudkitty/tests/collectors/test_gnocchi.py

@@ -157,8 +157,8 @@ class GnocchiCollectorAggregationOperationTest(tests.TestCase):
     def setUp(self):
         super(GnocchiCollectorAggregationOperationTest, self).setUp()
         self.conf.set_override('collector', 'gnocchi', 'collect')
-        self.start = datetime.datetime(2019, 1, 1, tzinfo=tz.UTC)
+        self.start = datetime.datetime(2019, 1, 1, tzinfo=tz.tzutc())
-        self.end = datetime.datetime(2019, 1, 1, 1, tzinfo=tz.UTC)
+        self.end = datetime.datetime(2019, 1, 1, 1, tzinfo=tz.tzutc())
 
     def do_test(self, expected_op, extra_args=None):
         conf = {

cloudkitty/tests/gabbi/fixtures.py

@@ -54,7 +54,7 @@ from cloudkitty import utils as ck_utils
 from cloudkitty.utils import tz as tzutils
 
 
-INITIAL_DT = datetime.datetime(2015, 1, 1, tzinfo=tz.UTC)
+INITIAL_DT = datetime.datetime(2015, 1, 1, tzinfo=tz.tzutc())
 
 
 class UUIDFixture(fixture.GabbiFixture):
@@ -377,7 +377,7 @@ class StorageDataFixture(BaseStorageDataFixture):
 
 class NowStorageDataFixture(BaseStorageDataFixture):
     def initialize_data(self):
-        dt = tzutils.get_month_start(naive=True).replace(tzinfo=tz.UTC)
+        dt = tzutils.get_month_start(naive=True).replace(tzinfo=tz.tzutc())
         hour_delta = datetime.timedelta(seconds=3600)
         limit = dt + hour_delta * 12
         while dt < limit:
@@ -501,7 +501,7 @@ class InfluxStorageDataFixture(StorageDataFixture):
 class UTCFixture(fixture.GabbiFixture):
     """Set the local timezone to UTC"""
     def start_fixture(self):
-        self._tzmock = mock.patch('cloudkitty.utils.tz._LOCAL_TZ', tz.UTC)
+        self._tzmock = mock.patch('cloudkitty.utils.tz._LOCAL_TZ', tz.tzutc())
         self._tzmock.start()
 
     def stop_fixture(self):

cloudkitty/tests/storage/v2/elasticsearch/test_client.py

@@ -38,8 +38,8 @@ class TestElasticsearchClient(unittest.TestCase):
         self.assertEqual(self.client._build_must(None, None, None, None), [])
 
     def test_build_must_with_start_end(self):
-        start = datetime.datetime(2019, 8, 30, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 8, 30, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 8, 31, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 8, 31, tzinfo=tz.tzutc())
         self.assertEqual(
             self.client._build_must(start, end, None, None),
             [{'range': {'start': {'gte': '2019-08-30T00:00:00+00:00'}}},

cloudkitty/tests/storage/v2/test_influxdb.py

@@ -42,7 +42,7 @@ class TestInfluxDBStorage(TestCase):
             'two': '2',
             '1': 'one',
             '2': 'two',
-            'time': datetime(2019, 1, 1, tzinfo=tz.UTC).isoformat(),
+            'time': datetime(2019, 1, 1, tzinfo=tz.tzutc()).isoformat(),
         }
 
     def test_point_to_dataframe_entry_valid_point(self):
@@ -81,10 +81,11 @@ class TestInfluxDBStorage(TestCase):
         self.assertEqual(len(dataframes), 3)
 
         for idx, frame in enumerate(dataframes):
-            self.assertEqual(frame.start, datetime(2019, 1, 1, tzinfo=tz.UTC))
+            self.assertEqual(
+                frame.start, datetime(2019, 1, 1, tzinfo=tz.tzutc()))
             delta = timedelta(seconds=(idx + 1) * 100)
             self.assertEqual(frame.end,
-                             datetime(2019, 1, 1, tzinfo=tz.UTC) + delta)
+                             datetime(2019, 1, 1, tzinfo=tz.tzutc()) + delta)
             typelist = list(frame.itertypes())
             self.assertEqual(len(typelist), 1)
             type_, points = typelist[0]

cloudkitty/tests/test_dataframe.py

@@ -154,8 +154,8 @@ class TestDataPoint(unittest.TestCase):
 class TestDataFrame(unittest.TestCase):
 
     def test_dataframe_add_points(self):
-        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.tzutc())
         df = dataframe.DataFrame(start=start, end=end)
         a_points = [dataframe.DataPoint(**TestDataPoint.default_params)
                     for _ in range(2)]
@@ -183,15 +183,15 @@ class TestDataFrame(unittest.TestCase):
         })
 
     def test_properties(self):
-        start = datetime.datetime(2019, 6, 1, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 6, 1, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 6, 1, 1, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 6, 1, 1, tzinfo=tz.tzutc())
         df = dataframe.DataFrame(start=start, end=end)
         self.assertEqual(df.start, start)
         self.assertEqual(df.end, end)
 
     def test_json(self):
-        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.tzutc())
         df = dataframe.DataFrame(start=start, end=end)
         a_points = [dataframe.DataPoint(**TestDataPoint.default_params)
                     for _ in range(2)]
@@ -217,8 +217,8 @@ class TestDataFrame(unittest.TestCase):
         })))
 
     def test_from_dict_valid_dict(self):
-        start = datetime.datetime(2019, 1, 2, 12, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 1, 2, 12, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 1, 2, 13, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 1, 2, 13, tzinfo=tz.tzutc())
         point = dataframe.DataPoint(
             'unit', 0, 0, {'g_one': 'one'}, {'m_two': 'two'})
         usage = {'metric_x': [point]}
@@ -232,8 +232,8 @@ class TestDataFrame(unittest.TestCase):
         )
 
     def test_from_dict_valid_dict_date_as_str(self):
-        start = datetime.datetime(2019, 1, 2, 12, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 1, 2, 12, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 1, 2, 13, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 1, 2, 13, tzinfo=tz.tzutc())
         point = dataframe.DataPoint(
             'unit', 0, 0, {'g_one': 'one'}, {'m_two': 'two'})
         usage = {'metric_x': [point]}
@@ -251,8 +251,8 @@ class TestDataFrame(unittest.TestCase):
             ValueError, dataframe.DataFrame.from_dict, {'usage': None})
 
     def test_repr(self):
-        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.tzutc())
         df = dataframe.DataFrame(start=start, end=end)
         points = [dataframe.DataPoint(**TestDataPoint.default_params)
                   for _ in range(4)]
@@ -262,8 +262,8 @@ class TestDataFrame(unittest.TestCase):
         self.assertEqual(str(df), "DataFrame(metrics=[metric_x,metric_y])")
 
     def test_iterpoints(self):
-        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.UTC)
+        start = datetime.datetime(2019, 3, 4, 1, tzinfo=tz.tzutc())
-        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.UTC)
+        end = datetime.datetime(2019, 3, 4, 2, tzinfo=tz.tzutc())
         df = dataframe.DataFrame(start=start, end=end)
         points = [dataframe.DataPoint(**TestDataPoint.default_params)
                   for _ in range(4)]

cloudkitty/tests/utils_tests/test_json.py

@@ -28,6 +28,6 @@ class JSONEncoderTest(tests.TestCase):
         self.assertEqual(json.dumps(obj), '{"nb": 42.0}')
 
     def test_encode_datetime(self):
-        obj = {'date': datetime.datetime(2019, 1, 1, tzinfo=tz.UTC)}
+        obj = {'date': datetime.datetime(2019, 1, 1, tzinfo=tz.tzutc())}
         self.assertEqual(json.dumps(obj),
                          '{"date": "2019-01-01T00:00:00+00:00"}')

cloudkitty/tests/utils_tests/test_tz.py

@@ -31,7 +31,7 @@ class TestTZUtils(unittest.TestCase):
 
     def test_localized_now(self):
         self.assertEqual(
-            self.local_now.astimezone(tz.UTC).replace(tzinfo=None),
+            self.local_now.astimezone(tz.tzutc()).replace(tzinfo=None),
             self.naive_now)
         self.assertIsNotNone(self.local_now.tzinfo)
 
@@ -63,15 +63,15 @@ class TestTZUtils(unittest.TestCase):
 
     def _test_add_substract_delta(self, obj, tzone):
         delta = datetime.timedelta(seconds=3600)
-        naive = obj.astimezone(tz.UTC).replace(tzinfo=None)
+        naive = obj.astimezone(tz.tzutc()).replace(tzinfo=None)
 
         self.assertEqual(
             tzutils.add_delta(obj, delta).astimezone(tzone),
-            (naive + delta).replace(tzinfo=tz.UTC).astimezone(tzone),
+            (naive + delta).replace(tzinfo=tz.tzutc()).astimezone(tzone),
         )
         self.assertEqual(
             tzutils.substract_delta(obj, delta).astimezone(tzone),
-            (naive - delta).replace(tzinfo=tz.UTC).astimezone(tzone),
+            (naive - delta).replace(tzinfo=tz.tzutc()).astimezone(tzone),
         )
 
     def test_add_substract_delta_summertime(self):
@@ -118,13 +118,13 @@ class TestTZUtils(unittest.TestCase):
         self.assertEqual(tzutils.diff_seconds(two, one), 30)
 
     def test_diff_seconds_positive_arg_aware_objects(self):
-        one = datetime.datetime(2019, 1, 1, 1, 1, 30, tzinfo=tz.UTC)
+        one = datetime.datetime(2019, 1, 1, 1, 1, 30, tzinfo=tz.tzutc())
-        two = datetime.datetime(2019, 1, 1, 1, 1, tzinfo=tz.UTC)
+        two = datetime.datetime(2019, 1, 1, 1, 1, tzinfo=tz.tzutc())
         self.assertEqual(tzutils.diff_seconds(one, two), 30)
 
     def test_diff_seconds_negative_arg_aware_objects(self):
-        one = datetime.datetime(2019, 1, 1, 1, 1, 30, tzinfo=tz.UTC)
+        one = datetime.datetime(2019, 1, 1, 1, 1, 30, tzinfo=tz.tzutc())
-        two = datetime.datetime(2019, 1, 1, 1, 1, tzinfo=tz.UTC)
+        two = datetime.datetime(2019, 1, 1, 1, 1, tzinfo=tz.tzutc())
         self.assertEqual(tzutils.diff_seconds(two, one), 30)
 
     def test_diff_seconds_negative_arg_aware_objects_on_summer_change(self):
@@ -136,7 +136,7 @@ class TestTZUtils(unittest.TestCase):
 
     def test_cloudkitty_dt_from_ts_as_utc(self):
         ts = 1569902400
-        dt = datetime.datetime(2019, 10, 1, 4, tzinfo=tz.UTC)
+        dt = datetime.datetime(2019, 10, 1, 4, tzinfo=tz.tzutc())
         self.assertEqual(dt, tzutils.dt_from_ts(ts, as_utc=True))
 
     def test_cloudkitty_dt_from_ts_local_tz(self):

cloudkitty/utils/tz.py

@@ -47,9 +47,9 @@ def local_to_utc(dt, naive=False):
     # applied to a naive datetime object. In python3 however, the naive object
     # is considered as being in the system's time.
     if dt.tzinfo is None:
-        dt = dt.replace(tzinfo=tz.UTC)
+        dt = dt.replace(tzinfo=tz.tzutc())
 
-    output = dt.astimezone(tz.UTC)
+    output = dt.astimezone(tz.tzutc())
     if naive:
         output = output.replace(tzinfo=None)
     return output
@@ -65,7 +65,7 @@ def utc_to_local(dt):
     :rtype: datetime.datetime
     """
     if dt.tzinfo is None:
-        dt = dt.replace(tzinfo=tz.UTC)
+        dt = dt.replace(tzinfo=tz.tzutc())
     return dt.astimezone(_LOCAL_TZ)
 
 
@@ -81,7 +81,7 @@ def dt_from_iso(time_str, as_utc=False):
     :rtype: datetime.datetime
     """
     return timeutils.parse_isotime(time_str).astimezone(
-        tz.UTC if as_utc else _LOCAL_TZ).replace(microsecond=0)
+        tz.tzutc() if as_utc else _LOCAL_TZ).replace(microsecond=0)
 
 
 def dt_from_ts(ts, as_utc=False):
@@ -89,7 +89,8 @@ def dt_from_ts(ts, as_utc=False):
 
     Returns the object as being from the local timezone.
     """
-    return datetime.datetime.fromtimestamp(ts, tz.UTC if as_utc else _LOCAL_TZ)
+    return datetime.datetime.fromtimestamp(
+        ts, tz.tzutc() if as_utc else _LOCAL_TZ)
 
 
 def add_delta(dt, delta):
@@ -134,7 +135,7 @@ def get_month_start(dt=None, naive=False):
     if not dt:
         dt = localized_now()
     if not dt.tzinfo:
-        dt = dt.replace(tzinfo=tz.UTC).astimezone(_LOCAL_TZ)
+        dt = dt.replace(tzinfo=tz.tzutc()).astimezone(_LOCAL_TZ)
     if naive:
         dt = local_to_utc(dt, naive=True)
     return datetime.datetime(dt.year, dt.month, 1, tzinfo=dt.tzinfo)

lower-constraints.txt

@@ -21,6 +21,7 @@ oslo.middleware==3.27.0 # Apache-2.0
 oslo.policy==0.5.0 # Apache-2.0
 oslo.utils==3.5.0 # Apache-2.0
 oslo.upgradecheck==0.1.1 # Apache-2.0
+python-dateutil==2.5.3 # BSD
 SQLAlchemy==1.0.10 # MIT
 six==1.9.0 # MIT
 stevedore==1.5.0 # Apache-2.0

releasenotes/notes/remove-dateutil-tz-utc-usage-1350c00be3fadde7.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    The use of ``tz.UTC`` from the ``dateutil`` package was removed, bringing
+    compatibility with the version available in RHEL and CentOS 8.

requirements.txt

@@ -23,6 +23,7 @@ oslo.middleware>=3.27.0 # Apache-2.0
 oslo.policy>=0.5.0 # Apache-2.0
 oslo.utils>=3.5.0 # Apache-2.0
 oslo.upgradecheck>=0.1.1 # Apache-2.0
+python-dateutil>=2.5.3 # BSD
 SQLAlchemy>=1.0.10,!=1.1.5,!=1.1.6,!=1.1.7,!=1.1.8 # MIT
 six>=1.9.0 # MIT
 stevedore>=1.5.0 # Apache-2.0