Add an option to log exceptions raised by tasks

It is common that users forget to handle exceptions properly in their
tasks, and since services tasks are supposed to run forever, there are
no many opportunities to await for their completion appropriately and
handle the failure.

With this at least we make sure we will get a log message when a task
raises an exception, so we can at least know what happened and they just
silently disappear.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/core/asyncio.py

@@ -20,9 +20,13 @@
 import asyncio
 import collections.abc
 import contextvars
+import logging
 from types import TracebackType
 from typing import Any, Protocol, Self, TypeVar, runtime_checkable
 
+_logger = logging.getLogger(__name__)
+
+
 TaskReturnT = TypeVar("TaskReturnT")
 """The type of the return value of a task."""
 
@@ -194,6 +198,7 @@ def create_task(
         *,
         name: str | None = None,
         context: contextvars.Context | None = None,
+        log_exception: bool = True,
     ) -> asyncio.Task[TaskReturnT]:
         """Start a managed task.
 
@@ -212,13 +217,26 @@ def create_task(
             coro: The coroutine to be managed.
             name: The name of the task.
             context: The context to be used for the task.
+            log_exception: Whether to log exceptions raised by the task.
 
         Returns:
             The new task.
         """
         task = self._task_creator.create_task(coro, name=name, context=context)
         self._tasks.add(task)
         task.add_done_callback(self._tasks.discard)
+
+        if log_exception:
+
+            def _log_exception(task: asyncio.Task[TaskReturnT]) -> None:
+                try:
+                    task.result()
+                except asyncio.CancelledError:
+                    pass
+                except BaseException:  # pylint: disable=broad-except
+                    _logger.exception("%s: Task %r raised an exception", self, task)
+
+            task.add_done_callback(_log_exception)
         return task
 
     def cancel(self, msg: str | None = None) -> None: