fix: include OCS error response bodies in logged errors

ex_app/lib/logger.py

@@ -1,7 +1,11 @@
 # SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
 # SPDX-License-Identifier: AGPL-3.0-or-later
 import asyncio
+import inspect
 import logging
+import traceback
+
+from nc_py_api import NextcloudException
 
 logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', handlers=[logging.StreamHandler()])
 logger = logging.getLogger('context_agent')
@@ -14,4 +18,46 @@ async def log(nc, level, content):
 	except asyncio.CancelledError:
 		raise
 	except Exception:
-		pass
+		pass
+
+MAX_RESPONSE_TEXT_LENGTH = 2000
+
+
+async def _ocs_response_text(e: NextcloudException) -> str | None:
+	response = getattr(e, 'response', None)
+	if response is None:
+		return None
+	try:
+		text = response.text
+		# niquests' AsyncResponse.text is a coroutine, the sync Response's is a str
+		if inspect.isawaitable(text):
+			text = await text
+	except asyncio.CancelledError:
+		raise
+	except Exception:
+		return None
+	if not isinstance(text, str):
+		return None
+	text = text.strip()
+	if not text:
+		return None
+	if len(text) > MAX_RESPONSE_TEXT_LENGTH:
+		text = text[:MAX_RESPONSE_TEXT_LENGTH] + '... (truncated)'
+	return text
+
+
+async def format_exception(e: BaseException) -> str:
+	"""Format an exception with its traceback, like traceback.format_exception,
+	and append the body of any OCS error response in its chain, since
+	str(NextcloudException) only carries the status code and reason."""
+	formatted = ''.join(traceback.format_exception(e))
+	seen = set()
+	current: BaseException | None = e
+	while current is not None and id(current) not in seen:
+		seen.add(id(current))
+		if isinstance(current, NextcloudException):
+			text = await _ocs_response_text(current)
+			if text is not None:
+				formatted += f'OCS response for [{current.status_code}]: {text}\n'
+		current = current.__cause__ or current.__context__
+	return formatted

ex_app/lib/main.py

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 import concurrent.futures
 import os
-import traceback
 from contextlib import asynccontextmanager
 from json import JSONDecodeError
 from threading import Event
@@ -23,7 +22,7 @@
 
 from ex_app.lib.agent import react
 from ex_app.lib.errors import UserFacingError
-from ex_app.lib.logger import log
+from ex_app.lib.logger import format_exception, log
 from ex_app.lib.mcp_server import UserAuthMiddleware, ToolListMiddleware
 from ex_app.lib.provider import provider, multimodal_provider
 from ex_app.lib.tools import get_categories
@@ -207,7 +206,7 @@ async def background_thread_task():
                         await asyncio.sleep(2)
                     continue
             except (NextcloudException, RequestException, JSONDecodeError) as e:
-                tb_str = ''.join(traceback.format_exception(e))
+                tb_str = await format_exception(e)
                 await log(nc, LogLvl.WARNING, "Error fetching the next task " + tb_str)
                 await wait_for_task(5)
                 continue
@@ -262,17 +261,17 @@ async def stream_output(intermediate_output):
                 )
             except (NextcloudException, RequestException) as stream_err:
                 stream_update_failed = True
-                tb_str = ''.join(traceback.format_exception(stream_err))
+                tb_str = await format_exception(stream_err)
                 await log(nc, LogLvl.WARNING, "Error streaming intermediate task result: " + tb_str)
 
         output = await react(task, nextcloud, stream_output=stream_output if stream_updates_enabled else None)
     except Exception as e:  # noqa
         try:
-            tb_str = ''.join(traceback.format_exception(e))
+            tb_str = await format_exception(e)
             await log(nc, LogLvl.ERROR, "Error: " + tb_str)
             await report_error(nc, task["id"], e)
         except (NextcloudException, RequestException) as net_err:
-            tb_str = ''.join(traceback.format_exception(net_err))
+            tb_str = await format_exception(net_err)
             await log(nc, LogLvl.WARNING, "Network error in reporting the error: " + tb_str)
         finally:
             async with NUM_RUNNING_TASKS_LOCK:
@@ -285,7 +284,7 @@ async def stream_output(intermediate_output):
         )
     except Exception as e:
         try:
-            tb_str = ''.join(traceback.format_exception(e))
+            tb_str = await format_exception(e)
             await log(nc, LogLvl.ERROR, "Error trying to report the task result: " + tb_str)
         except Exception:
             pass