Swarming: Creates Feature Flag to control its usage

src/clusterfuzz/_internal/base/feature_flags.py

@@ -35,6 +35,8 @@ class FeatureFlags(Enum):
 
   PREPROCESS_QUEUE_SIZE_LIMIT = 'preprocess_queue_size_limit'
 
+  SWARMING_REMOTE_EXECUTION = 'swarming_remote_execution'
+
   @property
   def flag(self):
     """Get the feature flag."""

src/clusterfuzz/_internal/swarming/__init__.py

@@ -19,6 +19,7 @@
 from google.protobuf import json_format
 
 from clusterfuzz._internal.base import utils
+from clusterfuzz._internal.base.feature_flags import FeatureFlags
 from clusterfuzz._internal.config import local_config
 from clusterfuzz._internal.datastore import data_types
 from clusterfuzz._internal.google_cloud_utils import credentials
@@ -33,8 +34,10 @@ def _requires_gpu() -> bool:
   return bool(utils.string_is_true(requires_gpu))
 
 
-def is_swarming_task(command: str, job_name: str):
+def is_swarming_task(command: str, job_name: str) -> bool:
   """Returns True if the task is supposed to run on swarming."""
+  if not FeatureFlags.SWARMING_REMOTE_EXECUTION.enabled:
+    return False
   job = data_types.Job.query(data_types.Job.name == job_name).get()
   if not job or not _requires_gpu():
     return False

src/clusterfuzz/_internal/tests/core/datastore/feature_flag_test.py

@@ -53,3 +53,11 @@ def test_get_and_set(self):
     self.assertEqual(feature_flags.FeatureFlags.TEST_FLOAT_FLAG.content, 1.23)
     self.assertEqual(feature_flags.FeatureFlags.TEST_FLOAT_FLAG.string_value,
                      'checker')
+
+  def test_not_found_in_db(self):
+    """Test that a feature flag returns empty or False values when not found in the DB."""
+    self.assertFalse(feature_flags.FeatureFlags.TEST_FLAG.enabled)
+    self.assertIsNone(feature_flags.FeatureFlags.TEST_FLAG.flag)
+    self.assertIsNone(feature_flags.FeatureFlags.TEST_FLAG.content)
+    self.assertEqual(feature_flags.FeatureFlags.TEST_FLAG.description, '')
+    self.assertEqual(feature_flags.FeatureFlags.TEST_FLAG.string_value, '')