[fix] Capture Anemoi Training subcommands in MLFlow (#61)

* fix: modify sysargv with subcommands

* docs: add changelog

CHANGELOG.md

@@ -31,6 +31,7 @@ Keep it human-readable, your future self will thank you!
 
 - Fix `TypeError` raised when trying to JSON serialise `datetime.timedelta` object - [#43](https://github.com/ecmwf/anemoi-training/pull/43)
 - Bugfixes for CI (#56)
+- Show correct subcommand in MLFlow - Addresses [#39](https://github.com/ecmwf/anemoi-training/issues/39) in [#61](https://github.com/ecmwf/anemoi-training/pull/61)
 
 ### Changed
 

src/anemoi/training/commands/train.py

@@ -29,19 +29,40 @@ class Train(Command):
     def add_arguments(parser: argparse.ArgumentParser) -> argparse.ArgumentParser:
         return parser
 
-    @staticmethod
-    def run(args: list[str], unknown_args: list[str] | None = None) -> None:
-        del args
+    def run(self, args: argparse.Namespace, unknown_args: list[str] | None = None) -> None:
+
+        # Merge the known subcommands with a non-whitespace character for hydra
+        new_sysargv = self._merge_sysargv(args)
 
+        # Add the unknown arguments (belonging to hydra) to sys.argv
         if unknown_args is not None:
-            sys.argv = [sys.argv[0], *unknown_args]
+            sys.argv = [new_sysargv, *unknown_args]
         else:
-            sys.argv = [sys.argv[0]]
+            sys.argv = [new_sysargv]
 
+        # Import and run the training command
         LOGGER.info("Running anemoi training command with overrides: %s", sys.argv[1:])
         from anemoi.training.train.train import main as anemoi_train
 
         anemoi_train()
 
+    def _merge_sysargv(self, args: argparse.Namespace) -> str:
+        """Merge the sys.argv with the known subcommands to pass to hydra.
+
+        Parameters
+        ----------
+        args : argparse.Namespace
+            args from the command line
+
+        Returns
+        -------
+        str
+            Modified sys.argv as string
+        """
+        modified_sysargv = f"{sys.argv[0]} {args.command}"
+        if hasattr(args, "subcommand"):
+            modified_sysargv += f" {args.subcommand}"
+        return modified_sysargv
+
 
 command = Train