Logging Handler for APM Log Forwarding (#548)

* Add log fowarding handler API.

* Fix pypy import

Author: TimPansino

newrelic/api/log.py

@@ -15,10 +15,11 @@
 import json
 import logging
 import re
+import warnings
 from logging import Formatter, LogRecord
 
 from newrelic.api.time_trace import get_linking_metadata
-from newrelic.api.transaction import current_transaction
+from newrelic.api.transaction import current_transaction, record_log_event
 from newrelic.common import agent_http
 from newrelic.common.object_names import parse_exc_info
 from newrelic.core.attribute import truncate
@@ -85,8 +86,25 @@ def safe_str(object, *args, **kwargs):
         return json.dumps(self.log_record_to_dict(record), default=safe_str, separators=(",", ":"))
 
 
+class NewRelicLogForwardingHandler(logging.Handler):
+    def emit(self, record):
+        try:
+            # Avoid getting local log decorated message
+            if hasattr(record, "_nr_original_message"):
+                message = record._nr_original_message()
+            else:
+                message = record.getMessage()
+
+            record_log_event(message, record.levelname, int(record.created * 1000))
+        except Exception:
+            self.handleError(record)
+
+
 class NewRelicLogHandler(logging.Handler):
-    """This is an experimental log handler provided by the community. Use with caution."""
+    """
+    Deprecated: Please use NewRelicLogForwardingHandler instead.
+    This is an experimental log handler provided by the community. Use with caution.
+    """
 
     PATH = "/log/v1"
 
@@ -104,6 +122,13 @@ def __init__(
         ca_bundle_path=None,
         disable_certificate_validation=False,
     ):
+        warnings.warn(
+            "The contributed NewRelicLogHandler has been superseded by automatic instrumentation for "
+            "logging in the standard lib. If for some reason you need to manually configure a handler, "
+            "please use newrelic.api.log.NewRelicLogForwardingHandler to take advantage of all the "
+            "features included in application log forwarding such as proper batching.", 
+            DeprecationWarning
+        )
         super(NewRelicLogHandler, self).__init__(level=level)
         self.license_key = license_key or self.settings.license_key
         self.host = host or self.settings.host or self.default_host(self.license_key)

tests/logger_logging/test_logging_handler.py

@@ -0,0 +1,68 @@
+# Copyright 2010 New Relic, Inc.
+#
+# 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.
+
+from conftest import logger as conf_logger
+import logging
+import pytest
+
+from newrelic.api.background_task import background_task
+from newrelic.api.log import NewRelicLogForwardingHandler
+from testing_support.fixtures import reset_core_stats_engine
+from testing_support.validators.validate_log_event_count import validate_log_event_count
+from testing_support.validators.validate_log_event_count_outside_transaction import validate_log_event_count_outside_transaction
+from testing_support.validators.validate_function_called import validate_function_called
+
+
+
+
+@pytest.fixture(scope="function")
+def uninstrument_logging():
+    instrumented = logging.Logger.callHandlers
+    while hasattr(logging.Logger.callHandlers, "__wrapped__"):
+        logging.Logger.callHandlers = logging.Logger.callHandlers.__wrapped__
+    yield
+    logging.Logger.callHandlers = instrumented
+
+
+@pytest.fixture(scope="function")
+def logger(conf_logger, uninstrument_logging):
+    handler = NewRelicLogForwardingHandler()
+    conf_logger.addHandler(handler)
+    yield conf_logger
+    conf_logger.removeHandler(handler)
+
+
+def exercise_logging(logger):
+    logger.warning("C")
+    assert len(logger.caplog.records) == 1
+
+
+def test_handler_inside_transaction(logger):
+    @validate_log_event_count(1)
+    @validate_function_called("newrelic.api.log", "NewRelicLogForwardingHandler.emit")
+    @background_task()
+    def test():
+        exercise_logging(logger)
+
+    test()
+
+
+@reset_core_stats_engine()
+def test_handler_outside_transaction(logger):
+    @validate_log_event_count_outside_transaction(1)
+    @validate_function_called("newrelic.api.log", "NewRelicLogForwardingHandler.emit")
+    def test():
+        exercise_logging(logger)
+
+    test()