Keep same extension when created tmp config file

src/orion/core/worker/consumer.py

@@ -118,9 +118,6 @@ def __call__(self, trial, **kwargs):
             True if the trial was successfully executed. False if the trial is broken.
 
         """
-        log.debug("Consumer context: %s", trial.working_dir)
-        os.makedirs(trial.working_dir, exist_ok=True)
-
         results_file = self._consume(trial, trial.working_dir)
 
         log.debug("Parsing results from file and fill corresponding Trial object.")
@@ -197,9 +194,16 @@ def get_execution_environment(self, trial, results_file="results.log"):
 
         return env
 
-    def _consume(self, trial, workdirname):
+    def _prepare_config(self, trial, workdirname):
+        log.debug("Consumer context: %s", trial.working_dir)
+        os.makedirs(trial.working_dir, exist_ok=True)
+
+        if self.template_builder.file_config_path:
+            _, suffix = os.path.splitext(self.template_builder.file_config_path)
+        else:
+            suffix = ".conf"
         config_file = tempfile.NamedTemporaryFile(
-            mode="w", prefix="trial_", suffix=".conf", dir=workdirname, delete=False
+            mode="w", prefix="trial_", suffix=suffix, dir=workdirname, delete=False
         )
         config_file.close()
         log.debug("New temp config file: %s", config_file.name)
@@ -209,6 +213,10 @@ def _consume(self, trial, workdirname):
         results_file.close()
         log.debug("New temp results file: %s", results_file.name)
 
+        return config_file, results_file
+
+    def _consume(self, trial, workdirname):
+        config_file, results_file = self._prepare_config(trial, workdirname)
         log.debug("Building command line argument and configuration for trial.")
         env = self.get_execution_environment(trial, results_file.name)
         cmd_args = self.template_builder.format(

tests/unittests/core/worker/test_consumer.py

@@ -79,6 +79,40 @@ def test_trial_working_dir_is_created(config):
     shutil.rmtree(trial.working_dir)
 
 
+@pytest.mark.usefixtures("storage")
+@pytest.mark.parametrize(
+    "config_path_name",
+    ["yaml_sample_path", "json_sample_path", "unknown_type_template_path"],
+)
+def test_trial_config_file_is_created_with_correct_ext(
+    config, config_path_name, request
+):
+    """Check that trial config file is created with correct extension."""
+    config_path = request.getfixturevalue(config_path_name)
+    config["metadata"]["user_args"].insert(1, f"--config={config_path}")
+    backward.populate_space(config)
+    exp = experiment_builder.build(**config)
+
+    trial = exp.space.sample()[0]
+
+    exp.register_trial(trial, status="reserved")
+
+    assert not os.path.exists(trial.working_dir)
+
+    con = Consumer(exp)
+    config_file, results_file = con._prepare_config(trial, trial.working_dir)
+
+    assert os.path.exists(trial.working_dir)
+    assert os.path.exists(config_file.name)
+
+    _, original_ext = os.path.splitext(config_path)
+    _, tmp_ext = os.path.splitext(config_file.name)
+
+    assert original_ext == tmp_ext
+
+    shutil.rmtree(trial.working_dir)
+
+
 def setup_code_change_mock(config, monkeypatch, ignore_code_changes):
     """Mock create experiment and trials, and infer_versioning_metadata"""
     exp = experiment_builder.build(**config)