AGE-148 : Get full function body details, when exception occurs (#56)

* recording function body

* Updated Record Exception flow to collect logical unit of exception

Author: bhogayatakb

middleware/__init__.py

@@ -1,4 +1,9 @@
 from middleware.distro import mw_tracker, record_exception
+from typing import Collection
+import sys
+from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
+from opentelemetry import trace
+from typing import Optional
 from middleware.options import (
     MWOptions,
     DETECT_AWS_BEANSTALK,
@@ -28,3 +33,22 @@
     "DETECT_GCP",
     "DETECT_ENVVARS",
 ]
+
+tracer = trace.get_tracer(__name__)
+
+class ExceptionInstrumentor(BaseInstrumentor):
+    def instrumentation_dependencies(self) -> Collection[str]:
+        """Return dependencies if this instrumentor requires any."""
+        return []
+    
+    def _instrument(self, **kwargs):
+        """Automatically sets sys.excepthook when the instrumentor is loaded."""
+        sys.excepthook = record_exception
+
+    def _uninstrument(self, **kwargs):
+        """Restores default sys.excepthook if needed."""
+        sys.excepthook = sys.__excepthook__
+
+# Load the instrumentor
+ExceptionInstrumentor().instrument()
+

middleware/distro.py

@@ -1,4 +1,7 @@
 import logging
+import inspect
+import traceback
+import sys
 from logging import getLogger
 from typing import Optional
 from opentelemetry.instrumentation.distro import BaseDistro
@@ -9,7 +12,8 @@
 from middleware.log import create_logger_handler
 from middleware.profiler import collect_profiling
 from opentelemetry import trace
-from opentelemetry.trace import Tracer, get_current_span, get_tracer
+from opentelemetry.trace import Tracer, get_current_span, get_tracer, Span
+
 
 _logger = getLogger(__name__)
 
@@ -80,6 +84,63 @@ def mw_tracker(
 
     mw_tracker_called = True
 
+def extract_function_code(tb_frame):
+    """Extracts the full function body where the exception occurred."""
+    try:
+        source_lines, _ = inspect.getsourcelines(tb_frame)
+        return "".join(source_lines)  # Convert to a string
+    except Exception:
+        return "Could not retrieve source code."
+
+# Replacement of span.record_exception to include function source code
+def custom_record_exception(span: Span, exc: Exception):
+    """Custom exception recording that captures function source code."""
+    exc_type, exc_value, exc_tb = exc.__class__, str(exc), exc.__traceback__
+
+    if exc_tb is None:
+        span.set_attribute("exception.warning", "No traceback available")
+        span.record_exception(exc)
+        return
+
+    tb_details = traceback.extract_tb(exc_tb)
+    
+    if not tb_details:
+        span.set_attribute("exception.warning", "Traceback is empty")
+        span.record_exception(exc)
+        return
+
+    last_tb = tb_details[-1]  # Get the last traceback entry (where exception occurred)
+    filename, lineno, func_name, _ = last_tb
+    
+    # Extract the correct frame from the traceback
+    tb_frame = None
+    for frame, _ in traceback.walk_tb(exc_tb):
+        if frame.f_code.co_name == func_name:
+            tb_frame = frame
+            break
+
+
+
+    function_code = extract_function_code(tb_frame) if tb_frame else "Function source not found."
+    
+     # Determine if the exception is escaping
+    current_exc = sys.exc_info()[1]  # Get the currently active exception
+    exception_escaped = current_exc is exc  # True if it's still propagating
+    
+    # Add extra details in the existing "exception" event
+    span.add_event(
+        "exception",  # Keep the event name as "exception"
+        {
+            "exception.type": str(exc_type.__name__),
+            "exception.message": exc_value,
+            "exception.stacktrace": traceback.format_exc(),
+            "exception.function_name": func_name,
+            "exception.file": filename,
+            "exception.line": lineno,
+            "exception.function_body": function_code,
+            "exception.escaped": exception_escaped,
+        }
+    )
 
 def record_exception(exc: Exception, span_name: Optional[str] = None) -> None:
     """
@@ -102,15 +163,15 @@ def record_exception(exc: Exception, span_name: Optional[str] = None) -> None:
 
     span = get_current_span()
     if span.is_recording():
-        span.record_exception(exc)
+        custom_record_exception(span, exc)
         return
 
     tracer: Tracer = get_tracer("mw-tracer")
     if span_name is None:
         span_name = type(exc).__name__
 
     span = tracer.start_span(span_name)
-    span.record_exception(exc)
+    custom_record_exception(span, exc)
     span.set_status(trace.Status(trace.StatusCode.ERROR, str(exc)))
     span.end()
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "middleware-io"
-version = "2.1.1"
+version = "2.1.2rc1"
 requires-python = ">=3.8"
 description = "Middleware's APM tool enables Python developers to effortlessly monitor their applications, gathering distributed tracing, metrics, logs, and profiling data for valuable insights and performance optimization."
 authors = [{ name = "middleware-dev" }]