Fix first_execution_time when used together with pattern

When specifying pattern only in the API request, the returned
first_execution_time should be the calculated according to the pattern.

When specifying first_execution_time and pattern both in the API
request, the first_execution_time will be tweaked according to the
pattern.

Change-Id: I0c71c2d76584c9b8335d6b379361779191e8c8d2
Story: 2003483
Task: 24750

qinling/tests/unit/api/controllers/v1/test_job.py

@@ -15,6 +15,8 @@
 from datetime import datetime
 from datetime import timedelta
 
+from dateutil import parser
+
 from qinling import context as auth_context
 from qinling.db import api as db_api
 from qinling import status
@@ -99,6 +101,31 @@ class TestJobController(base.APITest):
 
         self.assertEqual(201, resp.status_int)
 
+        res = resp.json
+        self.assertEqual(
+            res["first_execution_time"],
+            res["next_execution_time"]
+        )
+
+    def test_post_both_pattern_and_first_execution_time(self):
+        body = {
+            'name': self.rand_name('job', prefix=self.prefix),
+            'function_id': self.function_id,
+            'pattern': '0 21 * * *',
+            'first_execution_time': str(
+                datetime.utcnow() + timedelta(hours=1)),
+            'count': 10
+        }
+        resp = self.app.post_json('/v1/jobs', body)
+
+        self.assertEqual(201, resp.status_int)
+
+        res = resp.json
+        self.assertGreaterEqual(
+            parser.parse(res["next_execution_time"], ignoretz=True),
+            parser.parse(res["first_execution_time"], ignoretz=True)
+        )
+
     def test_delete(self):
         job_id = self.create_job(
             self.function_id,

qinling/utils/jobs.py

@@ -56,26 +56,29 @@ def validate_job(params):
 
     if not (first_time or pattern):
         raise exc.InputException(
-            'Pattern or first_execution_time must be specified.'
+            'pattern or first_execution_time must be specified.'
         )
 
     if first_time:
         first_time = validate_next_time(first_time)
         if not pattern and count and count > 1:
             raise exc.InputException(
-                'Pattern must be provided if count is greater than 1.'
+                'pattern must be provided if count is greater than 1.'
             )
 
         next_time = first_time
         if not (pattern or count):
             count = 1
-
     if pattern:
         validate_pattern(pattern)
-        if not first_time:
-            next_time = croniter.croniter(pattern, start_time).get_next(
-                datetime.datetime
-            )
+
+        if first_time:
+            start_time = first_time - datetime.timedelta(minutes=1)
+
+        next_time = croniter.croniter(pattern, start_time).get_next(
+            datetime.datetime
+        )
+        first_time = next_time
 
     return first_time, next_time, count
 

test-requirements.txt

@@ -10,5 +10,5 @@ testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 tempest>=17.1.0 # Apache-2.0
 futurist>=1.2.0 # Apache-2.0
-
 kubernetes>=6.0.0 # Apache-2.0
+python-dateutil>=2.5.3 # BSD