Allow stack traces in HTTP responses only if INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE is enabled (#12938)

sannya-singal · web-flow · commit cd7b481087e4 · 2025-08-11T09:28:22.000+05:30
diff --git a/localstack-core/localstack/aws/handlers/service.py b/localstack-core/localstack/aws/handlers/service.py
@@ -184,7 +184,7 @@ def create_exception_response(self, exception: Exception, context: RequestContex
             if not self.handle_internal_failures:
                 return
 
-            if config.DEBUG:
+            if config.INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE:
                 exception = "".join(
                     traceback.format_exception(
                         type(exception), value=exception, tb=exception.__traceback__
diff --git a/localstack-core/localstack/config.py b/localstack-core/localstack/config.py
@@ -823,6 +823,9 @@ def populate_edge_configuration(
 # Flag to enable the validation of the requests made to the LocalStack internal endpoints. Active by default.
 OPENAPI_VALIDATE_REQUEST = is_env_true("OPENAPI_VALIDATE_REQUEST")
 
+# environment variable to determine whether to include stack traces in http responses
+INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE = is_env_true("INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE")
+
 # whether to skip waiting for the infrastructure to shut down, or exit immediately
 FORCE_SHUTDOWN = is_env_not_false("FORCE_SHUTDOWN")
 
diff --git a/localstack-core/localstack/testing/pytest/in_memory_localstack.py b/localstack-core/localstack/testing/pytest/in_memory_localstack.py
@@ -71,6 +71,8 @@ def pytest_runtestloop(session: Session):
 
     # configure
     os.environ[ENV_INTERNAL_TEST_RUN] = "1"
+    localstack_config.INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE = True
+
     safe_requests.verify_ssl = False
 
     from localstack.runtime import current
diff --git a/tests/conftest.py b/tests/conftest.py
@@ -1,6 +1,9 @@
 import os
 
 import pytest
+from _pytest.monkeypatch import MonkeyPatch
+
+from localstack import config
 
 os.environ["LOCALSTACK_INTERNAL_TEST_RUN"] = "1"
 
@@ -87,3 +90,16 @@ def secondary_aws_client(secondary_aws_client_factory):
     from localstack.testing.aws.util import base_testing_aws_client
 
     return base_testing_aws_client(secondary_aws_client_factory)
+
+
+@pytest.fixture(scope="session", autouse=True)
+def enable_stack_trace_for_tests():
+    """
+    Ensure stack traces are enabled in HTTP responses during test sessions.
+
+    This is useful for debugging purposes.
+    """
+    mpatch = MonkeyPatch()
+    mpatch.setattr(config, "INCLUDE_STACK_TRACES_IN_HTTP_RESPONSE", True)
+    yield mpatch
+    mpatch.undo()
