Celery: Log exceptions into log

Apparently we can not expect everybody to setup error collection and log
should indicate the problems. Celery does swallow the exceptions
(actually it stores them as result, but Weblate doesn't care for results
for most of the operations), see https://stackoverflow.com/q/16658371/225718

Issue #2813
Issue #2850

Signed-off-by: Michal Čihař <michal@cihar.com>

docs/changes.rst

@@ -8,6 +8,7 @@ Not yet released.
 
 * Added support for simplified creating of similar components.
 * Added support for parsing translation flags from the XML based file formats.
+* Log exceptions into Celery log.
 
 weblate 3.7.1
 -------------

weblate/celery.py

@@ -55,6 +55,18 @@
 app.autodiscover_tasks()
 
 
+@task_failure.connect
+def handle_task_failure(exception=None, **kwargs):
+    from weblate.utils.errors import report_error
+    report_error(
+        exception,
+        extra_data=kwargs,
+        prefix='Failure while executing task',
+        skip_raven=True,
+        print_tb=True
+    )
+
+
 @app.on_after_configure.connect
 def configure_error_handling(sender, **kargs):
     """Rollbar and Sentry integration
@@ -74,10 +86,6 @@ def celery_base_data_hook(request, data):
 
         rollbar.BASE_DATA_HOOK = celery_base_data_hook
 
-        @task_failure.connect
-        def handle_task_failure(**kw):
-            rollbar.report_exc_info(extra_data=kw)
-
     if HAS_RAVEN and hasattr(settings, 'RAVEN_CONFIG'):
         client = Client(
             settings.RAVEN_CONFIG['dsn'],

weblate/utils/errors.py

@@ -38,7 +38,7 @@
 
 
 def report_error(error, request=None, extra_data=None, level='warning',
-                 prefix='Handled exception'):
+                 prefix='Handled exception', skip_raven=False, print_tb=False):
     """Wrapper for error reporting
 
     This can be used for store exceptions in error reporting solutions as
@@ -49,7 +49,7 @@ def report_error(error, request=None, extra_data=None, level='warning',
             request=request, extra_data=extra_data, level=level
         )
 
-    if HAS_RAVEN and hasattr(settings, 'RAVEN_CONFIG'):
+    if not skip_raven and HAS_RAVEN and hasattr(settings, 'RAVEN_CONFIG'):
         raven_client.captureException(
             request=request, extra=extra_data, level=level
         )
@@ -60,3 +60,5 @@ def report_error(error, request=None, extra_data=None, level='warning',
         error.__class__.__name__,
         force_text(error)
     )
+    if print_tb:
+        LOGGER.exception(prefix)