remove the limitation on (very) old DTSTART values for schedules

awx/api/serializers.py

@@ -4539,6 +4539,8 @@ class SchedulePreviewSerializer(BaseSerializer):
         try:
             Schedule.rrulestr(rrule_value)
         except Exception as e:
+            import traceback
+            logger.error(traceback.format_exc())
             raise serializers.ValidationError(_("rrule parsing failed validation: {}").format(e))
         return value
 

awx/main/models/schedules.py

@@ -191,7 +191,7 @@ class Schedule(PrimordialModel, LaunchTimeConfig):
         return rrule
 
     @classmethod
-    def rrulestr(cls, rrule, **kwargs):
+    def rrulestr(cls, rrule, fast_forward=True, **kwargs):
         """
         Apply our own custom rrule parsing requirements
         """
@@ -205,11 +205,17 @@ class Schedule(PrimordialModel, LaunchTimeConfig):
                     'A valid TZID must be provided (e.g., America/New_York)'
                 )
 
-        if 'MINUTELY' in rrule or 'HOURLY' in rrule:
+        if fast_forward and ('MINUTELY' in rrule or 'HOURLY' in rrule):
             try:
                 first_event = x[0]
-                if first_event < now() - datetime.timedelta(days=365 * 5):
-                    raise ValueError('RRULE values with more than 1000 events are not allowed.')
+                if first_event < now():
+                    # hourly/minutely rrules with far-past DTSTART values
+                    # are *really* slow to precompute
+                    # start *from* one week ago to speed things up drastically
+                    dtstart = x._rrule[0]._dtstart.strftime(':%Y%m%dT')
+                    new_start = (now() - datetime.timedelta(days=7)).strftime(':%Y%m%dT')
+                    new_rrule = rrule.replace(dtstart, new_start)
+                    return Schedule.rrulestr(new_rrule, fast_forward=False)
             except IndexError:
                 pass
         return x

awx/main/tests/functional/api/test_schedules.py

@@ -1,6 +1,8 @@
+import datetime
 import pytest
 
 from django.utils.encoding import smart_str
+from django.utils.timezone import now
 
 from awx.api.versioning import reverse
 from awx.main.models import JobTemplate, Schedule
@@ -140,7 +142,6 @@ def test_encrypted_survey_answer(post, patch, admin_user, project, inventory, su
     ("DTSTART:20030925T104941Z RRULE:FREQ=DAILY;INTERVAL=10;COUNT=500;UNTIL=20040925T104941Z", "RRULE may not contain both COUNT and UNTIL"),  # noqa
     ("DTSTART;TZID=America/New_York:20300308T050000Z RRULE:FREQ=DAILY;INTERVAL=1", "rrule parsing failed validation"),
     ("DTSTART:20300308T050000 RRULE:FREQ=DAILY;INTERVAL=1", "DTSTART cannot be a naive datetime"),
-    ("DTSTART:19700101T000000Z RRULE:FREQ=MINUTELY;INTERVAL=1", "more than 1000 events are not allowed"),  # noqa
 ])
 def test_invalid_rrules(post, admin_user, project, inventory, rrule, error):
     job_template = JobTemplate.objects.create(
@@ -342,6 +343,40 @@ def test_months_with_31_days(post, admin_user):
     ]
 
 
+@pytest.mark.django_db
+@pytest.mark.timeout(3)
+@pytest.mark.parametrize('freq, delta, total_seconds', (
+    ('MINUTELY', 1, 60),
+    ('MINUTELY', 15, 15 * 60),
+    ('HOURLY', 1, 3600),
+    ('HOURLY', 4, 3600 * 4),
+))
+def test_really_old_dtstart(post, admin_user, freq, delta, total_seconds):
+    url = reverse('api:schedule_rrule')
+    # every <interval>, at the :30 second mark
+    rrule = f'DTSTART;TZID=America/New_York:20051231T000030 RRULE:FREQ={freq};INTERVAL={delta}'
+    start = now()
+    next_ten = post(url, {'rrule': rrule}, admin_user, expect=200).data['utc']
+
+    assert len(next_ten) == 10
+
+    # the first date is *in the future*
+    assert next_ten[0] >= start
+
+    # ...but *no more than* <interval> into the future
+    assert now() + datetime.timedelta(**{
+        'minutes' if freq == 'MINUTELY' else 'hours': delta
+    })
+
+    # every date in the list is <interval> greater than the last
+    for i, x in enumerate(next_ten):
+        if i == 0:
+            continue
+        assert x.second == 30
+        delta = (x - next_ten[i - 1])
+        assert delta.total_seconds() == total_seconds
+
+
 def test_dst_rollback_duplicates(post, admin_user):
     # From Nov 2 -> Nov 3, 2030, daylight savings ends and we "roll back" an hour.
     # Make sure we don't "double count" duplicate times in the "rolled back"

awx/main/tests/functional/models/test_schedule.py

@@ -325,16 +325,19 @@ def test_dst_phantom_hour(job_template):
 
 
 @pytest.mark.django_db
+@pytest.mark.timeout(3)
 def test_beginning_of_time(job_template):
     # ensure that really large generators don't have performance issues
+    start = now()
     rrule = 'DTSTART:19700101T000000Z RRULE:FREQ=MINUTELY;INTERVAL=1'
     s = Schedule(
         name='Some Schedule',
         rrule=rrule,
         unified_job_template=job_template
     )
-    with pytest.raises(ValueError):
-        s.save()
+    s.save()
+    assert s.next_run > start
+    assert (s.next_run - start).total_seconds() < 60
 
 
 @pytest.mark.django_db