fix(arq): Don't monitor cron jobs with unsupported schedules (#8098)

Part of a series adding automatic Crons monitoring for the most-used job
schedulers in each SDK. Check-ins for a monitor that doesn't exist yet
are dropped, so today each monitor has to be created by hand with its
schedule copied from the code. Sending the job's schedule as the monitor
config lets Sentry create the monitor and keep it in sync.

This is a quick fix to keep the arq integration behaviour in line with
how other integrations work. Sorry for the churn!

Follow-up to #8051. Cron jobs whose schedule Crons can't express are no
longer monitored, instead of checking in without a config. This matches
Celery beat, and the Huey and RQ integrations from #8052 and #8053.

Docs: getsentry/sentry-docs#20056

Co-authored-by: Claude <noreply@anthropic.com>

Author: wedamija

sentry_sdk/integrations/arq.py

@@ -336,10 +336,11 @@ def _monitor_cron_job(
     monitor_config = _get_monitor_config(cron_job, worker)
     if monitor_config is None:
         logger.debug(
-            "arq cron job %r can't be expressed as a Sentry Crons schedule. "
-            "Sending check-ins without a monitor config.",
+            "Not monitoring arq cron job %r: its schedule can't be expressed "
+            "as a Sentry Crons schedule.",
             cron_job.name,
         )
+        return
 
     coroutine = cron_job.coroutine
 

tests/integrations/arq/test_arq_crons.py

@@ -30,6 +30,13 @@ def info(self, section):
         FakeSocket.info = info
 
 
+@pytest.fixture(autouse=True)
+def utc_local_time(monkeypatch):
+    # arq < 0.25 runs cron jobs in local time.
+    monkeypatch.setattr(time, "timezone", 0)
+    monkeypatch.setattr(time, "daylight", 0)
+
+
 def _check_ins(envelopes):
     return [
         item.payload.json
@@ -65,10 +72,7 @@ class WorkerSettings:
 
 
 @pytest.mark.asyncio
-async def test_cron_job_ok(sentry_init, capture_envelopes, monkeypatch):
-    # arq < 0.25 runs cron jobs in local time.
-    monkeypatch.setattr(time, "timezone", 0)
-    monkeypatch.setattr(time, "daylight", 0)
+async def test_cron_job_ok(sentry_init, capture_envelopes):
     sentry_init(integrations=[ArqIntegration(monitor_cron_jobs=True)])
     envelopes = capture_envelopes()
 
@@ -109,20 +113,32 @@ async def test_cron_job_error(sentry_init, capture_envelopes):
 
 
 @pytest.mark.asyncio
-async def test_cron_job_without_config(sentry_init, capture_envelopes):
+@pytest.mark.parametrize(
+    "kwargs, tz",
+    [
+        # Every 10 seconds can't be expressed as a crontab.
+        ({"second": {0, 10, 20, 30, 40, 50}}, timezone.utc),
+        ({"day": 1, "weekday": "mon"}, timezone.utc),
+        ({"minute": 0}, timezone(timedelta(hours=5, minutes=30))),
+    ],
+)
+async def test_unsupported_schedule_not_monitored(
+    sentry_init, capture_envelopes, monkeypatch, kwargs, tz
+):
+    monkeypatch.setattr(time, "timezone", -tz.utcoffset(None).total_seconds())
     sentry_init(integrations=[ArqIntegration(monitor_cron_jobs=True)])
     envelopes = capture_envelopes()
+    calls = []
+
+    async def job(ctx):
+        calls.append(1)
 
-    # Every 10 seconds can't be expressed as a crontab.
     await _run_cron_jobs(
-        cron(ok_job, second={0, 10, 20, 30, 40, 50}, run_at_startup=True),
-        timezone=timezone.utc,
+        cron(job, name="job", run_at_startup=True, **kwargs), timezone=tz
     )
 
-    # A scheduled run can follow the startup run.
-    check_ins = _check_ins(envelopes)
-    assert [c["status"] for c in check_ins[:2]] == ["in_progress", "ok"]
-    assert all("monitor_config" not in c for c in check_ins)
+    assert calls
+    assert _check_ins(envelopes) == []
 
 
 @pytest.mark.asyncio