[CLI] Save only the configuration used

CHANGELOG.md

@@ -429,6 +429,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Fixed wrong typehint for `Trainer.lightning_optimizers` ([#11155](https://github.com/PyTorchLightning/pytorch-lightning/pull/11155))
 
 
+- Fixed the format of the configuration saved automatically by the CLI's `SaveConfigCallback` ([#11532](https://github.com/PyTorchLightning/pytorch-lightning/pull/11532))
+
+
 - Fixed type promotion when tensors of higher category than float are logged ([#11401](https://github.com/PyTorchLightning/pytorch-lightning/pull/11401))
 
 

pytorch_lightning/utilities/cli.py

@@ -699,8 +699,8 @@ def _instantiate_trainer(self, config: Dict[str, Any], callbacks: List[Callback]
                 config["callbacks"].append(self.trainer_defaults["callbacks"])
         if self.save_config_callback and not config["fast_dev_run"]:
             config_callback = self.save_config_callback(
-                self.parser,
-                self.config,
+                self._parser(self.subcommand),
+                self.config.get(str(self.subcommand), self.config),
                 self.save_config_filename,
                 overwrite=self.save_config_overwrite,
                 multifile=self.save_config_multifile,
@@ -798,9 +798,7 @@ def get_automatic(
 
     def _get(self, config: Dict[str, Any], key: str, default: Optional[Any] = None) -> Any:
         """Utility to get a config value which might be inside a subcommand."""
-        if self.subcommand is not None:
-            return config[self.subcommand].get(key, default)
-        return config.get(key, default)
+        return config.get(str(self.subcommand), config).get(key, default)
 
     def _run_subcommand(self, subcommand: str) -> None:
         """Run the chosen subcommand."""

tests/utilities/test_cli.py

@@ -349,9 +349,7 @@ def test_lightning_cli_args(tmpdir):
     with open(config_path) as f:
         loaded_config = yaml.safe_load(f.read())
 
-    loaded_config = loaded_config["fit"]
     cli_config = cli.config["fit"].as_dict()
-
     assert cli_config["seed_everything"] == 1234
     assert "model" not in loaded_config and "model" not in cli_config  # no arguments to include
     assert loaded_config["data"] == cli_config["data"]
@@ -405,9 +403,7 @@ def test_lightning_cli_config_and_subclass_mode(tmpdir):
     with open(config_path) as f:
         loaded_config = yaml.safe_load(f.read())
 
-    loaded_config = loaded_config["fit"]
     cli_config = cli.config["fit"].as_dict()
-
     assert loaded_config["model"] == cli_config["model"]
     assert loaded_config["data"] == cli_config["data"]
     assert loaded_config["trainer"] == cli_config["trainer"]
@@ -1251,6 +1247,10 @@ def test_lightning_cli_config_before_subcommand():
     test_mock.assert_called_once_with(cli.trainer, model=cli.model, verbose=True, ckpt_path="foobar")
     assert cli.trainer.limit_test_batches == 1
 
+    save_config_callback = cli.trainer.callbacks[0]
+    assert save_config_callback.config.trainer.limit_test_batches == 1
+    assert save_config_callback.parser.subcommand == "test"
+
     with mock.patch("sys.argv", ["any.py", f"--config={config}", "validate"]), mock.patch(
         "pytorch_lightning.Trainer.validate", autospec=True
     ) as validate_mock:
@@ -1259,6 +1259,10 @@ def test_lightning_cli_config_before_subcommand():
     validate_mock.assert_called_once_with(cli.trainer, cli.model, verbose=False, ckpt_path="barfoo")
     assert cli.trainer.limit_val_batches == 1
 
+    save_config_callback = cli.trainer.callbacks[0]
+    assert save_config_callback.config.trainer.limit_val_batches == 1
+    assert save_config_callback.parser.subcommand == "validate"
+
 
 def test_lightning_cli_config_before_subcommand_two_configs():
     config1 = {"validate": {"trainer": {"limit_val_batches": 1}, "verbose": False, "ckpt_path": "barfoo"}}