SERVER-40749: Do not create generate.tasks configuration on task restart

(cherry picked from commit be545c5b9b838456b456896959e891ceeab93758)

2 files changed, 76 insertions, 0 deletions

diff --git a/buildscripts/evergreen_generate_resmoke_tasks.py b/buildscripts/evergreen_generate_resmoke_tasks.py
index 3c2f61da7bd..4e9b184b813 100755
--- a/buildscripts/evergreen_generate_resmoke_tasks.py
+++ b/buildscripts/evergreen_generate_resmoke_tasks.py
@@ -365,6 +365,28 @@ def calculate_timeout(avg_runtime, scaling_factor):
     return max(MIN_TIMEOUT_SECONDS, round_to_minute(avg_runtime)) * scaling_factor
 
 
+def should_tasks_be_generated(evg_api, task_id):
+    """
+    Determine if we should attempt to generate tasks.
+
+    If an evergreen task that calls 'generate.tasks' is restarted, the 'generate.tasks' command
+    will no-op. So, if we are in that state, we should avoid generating new configuration files
+    that will just be confusing to the user (since that would not be used).
+
+    :param evg_api: Evergreen API object.
+    :param task_id: Id of the task being run.
+    :return: Boolean of whether to generate tasks.
+    """
+    task = evg_api.task_by_id(task_id, fetch_all_executions=True)
+    # If any previous execution was successful, do not generate more tasks.
+    for i in range(task.execution):
+        task_execution = task.get_execution(i)
+        if task_execution.is_success():
+            return False
+
+    return True
+
+
 class EvergreenConfigGenerator(object):
     """Generate evergreen configurations."""
 
@@ -702,6 +724,10 @@ class GenerateSubSuites(object):
         """Generate resmoke suites that run within a specified target execution time."""
         LOGGER.debug("config options", config_options=self.config_options)
 
+        if not should_tasks_be_generated(self.evergreen_api, self.config_options.task_id):
+            LOGGER.info("Not generating configuration due to previous successful generation.")
+            return
+
         end_date = datetime.datetime.utcnow().replace(microsecond=0)
         start_date = end_date - datetime.timedelta(days=LOOKBACK_DURATION_DAYS)
 
diff --git a/buildscripts/tests/test_evergreen_generate_resmoke_tasks.py b/buildscripts/tests/test_evergreen_generate_resmoke_tasks.py
index e108bfbf727..4432002c6cf 100644
--- a/buildscripts/tests/test_evergreen_generate_resmoke_tasks.py
+++ b/buildscripts/tests/test_evergreen_generate_resmoke_tasks.py
@@ -825,3 +825,53 @@ class GenerateSubSuitesTest(unittest.TestCase):
             self.assertIn(tests_runtimes[2], filtered_list)
             self.assertIn(tests_runtimes[0], filtered_list)
             self.assertEqual(2, len(filtered_list))
+
+
+class TestShouldTasksBeGenerated(unittest.TestCase):
+    def test_during_first_execution(self):
+        evg_api = MagicMock()
+        task_id = "task_id"
+        evg_api.task_by_id.return_value.execution = 0
+
+        self.assertTrue(under_test.should_tasks_be_generated(evg_api, task_id))
+        evg_api.task_by_id.assert_called_with(task_id, fetch_all_executions=True)
+
+    def test_after_successful_execution(self):
+        evg_api = MagicMock()
+        task_id = "task_id"
+        task = evg_api.task_by_id.return_value
+        task.execution = 1
+        task.get_execution.return_value.is_success.return_value = True
+
+        self.assertFalse(under_test.should_tasks_be_generated(evg_api, task_id))
+        evg_api.task_by_id.assert_called_with(task_id, fetch_all_executions=True)
+
+    def test_after_multiple_successful_execution(self):
+        evg_api = MagicMock()
+        task_id = "task_id"
+        task = evg_api.task_by_id.return_value
+        task.execution = 5
+        task.get_execution.return_value.is_success.return_value = True
+
+        self.assertFalse(under_test.should_tasks_be_generated(evg_api, task_id))
+        evg_api.task_by_id.assert_called_with(task_id, fetch_all_executions=True)
+
+    def test_after_failed_execution(self):
+        evg_api = MagicMock()
+        task_id = "task_id"
+        task = evg_api.task_by_id.return_value
+        task.execution = 1
+        task.get_execution.return_value.is_success.return_value = False
+
+        self.assertTrue(under_test.should_tasks_be_generated(evg_api, task_id))
+        evg_api.task_by_id.assert_called_with(task_id, fetch_all_executions=True)
+
+    def test_after_multiple_failed_execution(self):
+        evg_api = MagicMock()
+        task_id = "task_id"
+        task = evg_api.task_by_id.return_value
+        task.execution = 5
+        task.get_execution.return_value.is_success.return_value = False
+
+        self.assertTrue(under_test.should_tasks_be_generated(evg_api, task_id))
+        evg_api.task_by_id.assert_called_with(task_id, fetch_all_executions=True)