Add support for LogRecord.stack_info

Author: sethmlarson

ecs_logging/_stdlib.py

@@ -61,6 +61,8 @@ def __init__(self, stack_trace_limit=None, exclude_fields=()):
             Specifies the maximum number of frames to include for stack
             traces. Defaults to ``None`` which includes all available frames.
             Setting this to zero will suppress stack traces.
+            This setting doesn't affect ``LogRecord.stack_info`` because
+            this attribute is typically already pre-formatted.
         :param Sequence[str] exclude_fields:
             Specifies any fields that should be suppressed from the resulting
             fields, expressed with dot notation::
@@ -203,13 +205,20 @@ def _record_attribute(self, attribute):
 
     def _record_error_stack_trace(self, record):
         # type: (logging.LogRecord) -> Optional[str]
-        if not (
+        # Using stack_info=True will add 'error.stack_trace' even
+        # if the type is not 'error', exc_info=True only gathers
+        # when there's an active exception.
+        if (
             record.exc_info
             and record.exc_info[2] is not None
             and (self._stack_trace_limit is None or self._stack_trace_limit > 0)
         ):
-            return None
-        return (
-            "".join(format_tb(record.exc_info[2], limit=self._stack_trace_limit))
-            or None
-        )
+            return (
+                "".join(format_tb(record.exc_info[2], limit=self._stack_trace_limit))
+                or None
+            )
+        # LogRecord only has 'stack_info' if it's passed via .log(..., stack_info=True)
+        stack_info = getattr(record, "stack_info", None)
+        if stack_info:
+            return str(stack_info)
+        return None

tests/test_stdlib_formatter.py

@@ -4,10 +4,16 @@
 import json
 import time
 import random
+import sys
 import ecs_logging
 from .compat import StringIO
 
 
+requires_py3 = pytest.mark.skipif(
+    sys.version_info[0] < 3, reason="Test requires Python 3.x+"
+)
+
+
 @pytest.fixture(scope="function")
 def logger():
     return logging.getLogger("test-logger-%f-%f" % (time.time(), random.random()))
@@ -258,3 +264,34 @@ def test_exclude_fields_type_and_values():
     with pytest.raises(TypeError) as e:
         ecs_logging.StdlibFormatter(exclude_fields=[1])
     assert str(e.value) == "'exclude_fields' must be a sequence of strings"
+
+
+@requires_py3
+def test_stack_info(logger):
+    stream = StringIO()
+    handler = logging.StreamHandler(stream)
+    handler.setFormatter(ecs_logging.StdlibFormatter())
+    logger.addHandler(handler)
+    logger.setLevel(logging.DEBUG)
+
+    logger.info("stack info!", stack_info=True)
+
+    ecs = json.loads(stream.getvalue().rstrip())
+    assert list(ecs["error"].keys()) == ["stack_trace"]
+    error_stack_trace = ecs["error"].pop("stack_trace")
+    assert "test_stack_info" in error_stack_trace and __file__ in error_stack_trace
+
+
+@requires_py3
+@pytest.mark.parametrize("exclude_fields", [["error"], ["error.stack_trace"]])
+def test_stack_info_excluded(logger, exclude_fields):
+    stream = StringIO()
+    handler = logging.StreamHandler(stream)
+    handler.setFormatter(ecs_logging.StdlibFormatter(exclude_fields=exclude_fields))
+    logger.addHandler(handler)
+    logger.setLevel(logging.DEBUG)
+
+    logger.info("stack info!", stack_info=True)
+
+    ecs = json.loads(stream.getvalue().rstrip())
+    assert "error" not in ecs