Add a custom JSONEncoder

A custom JSONEncoder allowing to serialize decimal.Decimal instances
is defined in several places in the codebase. This provides a common
encoder class that supports decimal.Decimal and datetime.datetime objects.

Change-Id: Ie65b1f97f2eeb7a8bc6203576bdbc50b109867cc

cloudkitty/json_utils.py

@@ -0,0 +1,35 @@
+# Copyright 2019 Objectif Libre
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+#
+import datetime
+import decimal
+import functools
+import json
+
+from cloudkitty import utils as ck_utils
+
+
+class CloudkittyJSONEncoder(json.JSONEncoder):
+    """Cloudkitty custom json encoder."""
+
+    def default(self, obj):
+        if isinstance(obj, decimal.Decimal):
+            return float(obj)
+        elif isinstance(obj, datetime.datetime):
+            return ck_utils.dt2iso(obj)
+        return super(CloudkittyJSONEncoder, self).default(obj)
+
+
+dumps = functools.partial(json.dumps, cls=CloudkittyJSONEncoder)
+loads = json.loads

cloudkitty/state.py

@@ -15,10 +15,8 @@
 #
 # @author: Stéphane Albert
 #
-import decimal
-import json
-
 from cloudkitty.db import api
+from cloudkitty import json_utils as json
 
 
 class StateManager(object):
@@ -94,14 +92,6 @@ class StateManager(object):
         return self._metadata
 
 
-class DecimalJSONEncoder(json.JSONEncoder):
-    """Wrapper class to handle decimal.Decimal objects in json.dumps()."""
-    def default(self, obj):
-        if isinstance(obj, decimal.Decimal):
-            return float(obj)
-        return super(DecimalJSONEncoder, self).default(obj)
-
-
 class DBStateManager(object):
     def __init__(self, user_id, report_type, distributed=False):
         self._state_name = self._gen_name(report_type, user_id)
@@ -132,5 +122,4 @@ class DBStateManager(object):
     def set_metadata(self, metadata):
         """Set metadata attached to the state."""
 
-        self._db.set_metadata(self._state_name,
-                              json.dumps(metadata, cls=DecimalJSONEncoder))
+        self._db.set_metadata(self._state_name, json.dumps(metadata))

cloudkitty/storage/v1/hybrid/backends/gnocchi.py

@@ -17,7 +17,6 @@
 #
 import datetime
 import decimal
-import json
 
 from gnocchiclient import client as gclient
 from gnocchiclient import exceptions as gexceptions
@@ -28,6 +27,7 @@ from oslo_utils import uuidutils
 import six
 
 from cloudkitty.collector import validate_conf
+from cloudkitty import json_utils as json
 from cloudkitty.storage.v1.hybrid.backends import BaseHybridBackend
 import cloudkitty.utils as ck_utils
 
@@ -67,14 +67,6 @@ RESOURCE_TYPE_NAME_ROOT = 'rating_service_'
 METADATA_NAME_ROOT = 'ckmeta_'
 
 
-class DecimalJSONEncoder(json.JSONEncoder):
-    """Wrapper class to handle decimal.Decimal objects in json.dumps()."""
-    def default(self, obj):
-        if isinstance(obj, decimal.Decimal):
-            return float(obj)
-        return super(DecimalJSONEncoder, self).default(obj)
-
-
 class UnknownResourceType(Exception):
     """Exception raised when an unknown resource type is encountered"""
 

cloudkitty/storage/v1/sqlalchemy/__init__.py

@@ -16,12 +16,12 @@
 # @author: Stéphane Albert
 #
 import decimal
-import json
 
 from oslo_db.sqlalchemy import utils
 import sqlalchemy
 
 from cloudkitty import db
+from cloudkitty import json_utils as json
 from cloudkitty.storage import NoTimeFrame
 from cloudkitty.storage import v1 as storage
 from cloudkitty.storage.v1.sqlalchemy import migration
@@ -29,14 +29,6 @@ from cloudkitty.storage.v1.sqlalchemy import models
 from cloudkitty import utils as ck_utils
 
 
-class DecimalJSONEncoder(json.JSONEncoder):
-    """Wrapper class to handle decimal.Decimal objects in json.dumps()."""
-    def default(self, obj):
-        if isinstance(obj, decimal.Decimal):
-            return float(obj)
-        return super(DecimalJSONEncoder, self).default(obj)
-
-
 class SQLAlchemyStorage(storage.BaseStorage):
     """SQLAlchemy Storage Backend
 
@@ -185,7 +177,7 @@ class SQLAlchemyStorage(storage.BaseStorage):
         rate = rating_dict.get('price')
         if not rate:
             rate = decimal.Decimal(0)
-        desc = json.dumps(frame['desc'], cls=DecimalJSONEncoder)
+        desc = json.dumps(frame['desc'])
         self.add_time_frame(begin=self.usage_start_dt.get(tenant_id),
                             end=self.usage_end_dt.get(tenant_id),
                             tenant_id=tenant_id,

cloudkitty/storage/v1/sqlalchemy/models.py

@@ -15,14 +15,14 @@
 #
 # @author: Stéphane Albert
 #
-import json
-
 from oslo_db.sqlalchemy import models
 import sqlalchemy
 from sqlalchemy.ext import declarative
 
+from cloudkitty import json_utils as json
 from cloudkitty import utils as ck_utils
 
+
 Base = declarative.declarative_base()
 
 

cloudkitty/tests/test_json.py

@@ -0,0 +1,30 @@
+# Copyright 2019 Objectif Libre
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+#
+import datetime
+import decimal
+
+from cloudkitty import json_utils as json
+from cloudkitty import tests
+
+
+class JSONEncoderTest(tests.TestCase):
+
+    def test_encode_decimal(self):
+        obj = {'nb': decimal.Decimal(42)}
+        self.assertEqual(json.dumps(obj), '{"nb": 42.0}')
+
+    def test_encode_datetime(self):
+        obj = {'date': datetime.datetime(2019, 1, 1)}
+        self.assertEqual(json.dumps(obj), '{"date": "2019-01-01T00:00:00Z"}')

cloudkitty/writer/osrf.py

@@ -15,20 +15,12 @@
 #
 # @author: Stéphane Albert
 #
-import decimal
-import json
 import os
 
+from cloudkitty import json_utils as json
 from cloudkitty import writer
 
 
-class DecimalEncoder(json.JSONEncoder):
-    def default(self, o):
-        if isinstance(o, decimal.Decimal):
-            return float(o)
-        return super(DecimalEncoder, self).default(o)
-
-
 class OSRFBackend(writer.BaseReportWriter):
     """OpenStack Report Format Writer:
 
@@ -59,7 +51,7 @@ class OSRFBackend(writer.BaseReportWriter):
 
     def _write_total(self):
         total = {'total': self.total}
-        self._report.write(json.dumps(total, cls=DecimalEncoder))
+        self._report.write(json.dumps(total))
         self._report.write(']')
         self._report.flush()
 
@@ -96,6 +88,6 @@ class OSRFBackend(writer.BaseReportWriter):
                           'end': self.usage_end_dt.isoformat()}
         data['usage'] = self._usage_data
 
-        self._report.write(json.dumps(data, cls=DecimalEncoder))
+        self._report.write(json.dumps(data))
         self._report.write(', ')
         self._report.flush()

contrib/ci/csv_writer.py

@@ -20,11 +20,12 @@ import calendar
 import copy
 import csv
 import datetime
-import json
 import random
 import sys
 import uuid
 
+from cloudkitty import json_utils as json
+
 
 COMPUTE = {
     "type": "compute",