feat: add exception logging function, add tests (#344)

Author: sgoral-splunk

solnlib/log.py

@@ -19,6 +19,7 @@
 import logging
 import logging.handlers
 import os.path as op
+import traceback
 from threading import Lock
 from typing import Dict, Any
 
@@ -263,3 +264,25 @@ def events_ingested(
             "n_events": n_events,
         },
     )
+
+
+def log_exception(
+    logger: logging.Logger,
+    e: Exception,
+    full_msg: bool = True,
+    msg_before: str = None,
+    msg_after: str = None,
+    log_level: int = logging.ERROR,
+):
+    """General function to log exceptions."""
+    exc_type, exc_value, exc_traceback = type(e), e, e.__traceback__
+    if full_msg:
+        error = traceback.format_exception(exc_type, exc_value, exc_traceback)
+    else:
+        error = traceback.format_exception_only(exc_type, exc_value)
+
+    msg_start = msg_before if msg_before is not None else ""
+    msg_mid = "".join(error)
+    msg_end = msg_after if msg_after is not None else ""
+    msg = f"{msg_start}\n{msg_mid}\n{msg_end}"
+    logger.log(log_level, msg)

tests/unit/test_log.py

@@ -15,10 +15,12 @@
 #
 
 import logging
+import json
 import multiprocessing
 import os
 import shutil
 import threading
+import traceback
 import time
 from unittest import mock
 
@@ -197,3 +199,34 @@ def test_events_ingested():
             logging.INFO,
             "action=events_ingested modular_input_name=modular_input_name sourcetype_ingested=sourcetype n_events=5",
         )
+
+
+def test_log_exceptions_full_msg():
+    start_msg = "some msg before exception"
+    with mock.patch("logging.Logger") as mock_logger:
+        try:
+            test_jsons = "{'a': 'aa'"
+            json.loads(test_jsons)
+        except Exception as e:
+            log.log_exception(mock_logger, e, msg_before=start_msg)
+            mock_logger.log.assert_called_with(
+                logging.ERROR, f"{start_msg}\n{traceback.format_exc()}\n"
+            )
+
+
+def test_log_exceptions_partial_msg():
+    start_msg = "some msg before exception"
+    end_msg = "some msg after exception"
+    with mock.patch("logging.Logger") as mock_logger:
+        try:
+            test_jsons = "{'a': 'aa'"
+            json.loads(test_jsons)
+        except Exception as e:
+            log.log_exception(
+                mock_logger, e, full_msg=False, msg_before=start_msg, msg_after=end_msg
+            )
+            mock_logger.log.assert_called_with(
+                logging.ERROR,
+                "some msg before exception\njson.decoder.JSONDecodeError: Expecting property name enclosed in double "
+                "quotes: line 1 column 2 (char 1)\n\nsome msg after exception",
+            )