Allow to opt-out from logging results (#352)

* Add attribute Worker.log_results

* Do not log result when Worker.log_results is False

* Add description for the new parameter

Author: iamlikeme

arq/worker.py

@@ -170,6 +170,8 @@ class Worker:
     :param job_deserializer: a function that deserializes bytes into Python objects, defaults to pickle.loads
     :param expires_extra_ms: the default length of time from when a job is expected to start
      after which the job expires, defaults to 1 day in ms.
+    :param log_results: when set to true (default) results for successful jobs
+      will be logged
     """
 
     def __init__(
@@ -202,6 +204,7 @@ def __init__(
         job_serializer: Optional[Serializer] = None,
         job_deserializer: Optional[Deserializer] = None,
         expires_extra_ms: int = expires_extra_ms,
+        log_results: bool = True,
     ):
         self.functions: Dict[str, Union[Function, CronJob]] = {f.name: f for f in map(func, functions)}
         if queue_name is None:
@@ -266,6 +269,7 @@ def __init__(
         self.job_serializer = job_serializer
         self.job_deserializer = job_deserializer
         self.expires_extra_ms = expires_extra_ms
+        self.log_results = log_results
 
     def run(self) -> None:
         """
@@ -553,7 +557,7 @@ async def job_failed(exc: BaseException) -> None:
                     exc_extra = exc_extra()
                 raise
             else:
-                result_str = '' if result is None else truncate(repr(result))
+                result_str = '' if result is None or not self.log_results else truncate(repr(result))
             finally:
                 del self.job_tasks[job_id]
 

tests/test_worker.py

@@ -126,6 +126,17 @@ async def test_job_successful(arq_redis: ArqRedis, worker, caplog):
     assert 'X.XXs → testing:foobar()\n  X.XXs ← testing:foobar ● 42' in log
 
 
+async def test_job_successful_no_result_logging(arq_redis: ArqRedis, worker, caplog):
+    caplog.set_level(logging.INFO)
+    await arq_redis.enqueue_job('foobar', _job_id='testing')
+    worker: Worker = worker(functions=[foobar], log_results=False)
+    await worker.main()
+
+    log = re.sub(r'\d+.\d\ds', 'X.XXs', '\n'.join(r.message for r in caplog.records))
+    assert log.endswith('X.XXs → testing:foobar()\n  X.XXs ← testing:foobar ● ')
+    assert '42' not in log
+
+
 async def test_job_retry(arq_redis: ArqRedis, worker, caplog):
     async def retry(ctx):
         if ctx['job_try'] <= 2: