Default Observed Timestamp (#3377)

Co-authored-by: Diego Hurtado <ocelotl@users.noreply.github.com>

CHANGELOG.md

@@ -27,6 +27,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   [#3362](https://github.com/open-telemetry/opentelemetry-python/pull/3362))
 - Fixed bug where logging export is tracked as trace
   [#3375](https://github.com/open-telemetry/opentelemetry-python/pull/3375))
+- Default LogRecord observed_timestamp to current timestamp
+  [#3377](https://github.com/open-telemetry/opentelemetry-python/pull/3377))
 
 
 ## Version 1.18.0/0.39b0 (2023-05-19)

opentelemetry-api/src/opentelemetry/_logs/_internal/__init__.py

@@ -37,6 +37,7 @@
 from abc import ABC, abstractmethod
 from logging import getLogger
 from os import environ
+from time import time_ns
 from typing import Any, Optional, cast
 
 from opentelemetry._logs.severity import SeverityNumber
@@ -70,6 +71,8 @@ def __init__(
         attributes: Optional["Attributes"] = None,
     ):
         self.timestamp = timestamp
+        if observed_timestamp is None:
+            observed_timestamp = time_ns()
         self.observed_timestamp = observed_timestamp
         self.trace_id = trace_id
         self.span_id = span_id

opentelemetry-api/tests/logs/test_log_record.py

@@ -0,0 +1,27 @@
+# Copyright The OpenTelemetry Authors
+#
+# 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 unittest
+from unittest.mock import patch
+
+from opentelemetry._logs import LogRecord
+
+OBSERVED_TIMESTAMP = "OBSERVED_TIMESTAMP"
+
+
+class TestLogRecord(unittest.TestCase):
+    @patch("opentelemetry._logs._internal.time_ns")
+    def test_log_record_observed_timestamp_default(self, time_ns_mock):  # type: ignore
+        time_ns_mock.return_value = OBSERVED_TIMESTAMP
+        self.assertEqual(LogRecord().observed_timestamp, OBSERVED_TIMESTAMP)