add "cfg" argument for overriding any config from command line

freqtrade/commands/arguments.py

@@ -10,7 +10,7 @@ from freqtrade.commands.cli_options import AVAILABLE_CLI_OPTIONS
 from freqtrade.constants import DEFAULT_CONFIG
 
 
-ARGS_COMMON = ["verbosity", "logfile", "version", "config", "datadir", "user_data_dir"]
+ARGS_COMMON = ["verbosity", "logfile", "version", "config", "cfg", "datadir", "user_data_dir"]
 
 ARGS_STRATEGY = ["strategy", "strategy_path"]
 

freqtrade/commands/cli_options.py

@@ -1,6 +1,7 @@
 """
 Definition of cli arguments used in arguments.py
 """
+import argparse
 from argparse import ArgumentTypeError
 
 from freqtrade import __version__, constants
@@ -38,6 +39,50 @@ class Arg:
         self.kwargs = kwargs
 
 
+class SetDictFromArgAction(argparse.Action):
+    """
+    argparse action to split an argument into KEY=VALUE form
+    on the first = and append to a dictionary.
+    """
+
+    def __call__(self, parser, args, values, option_string=None):
+        for key_value in values:
+            try:
+                (k, v) = key_value.split("=", 2)
+            except ValueError as ex:
+                raise argparse.ArgumentError(self, f"could not parse argument \"{values[0]}\" as k=v format")
+            d = self.set_dict_path_value(getattr(args, self.dest) or {}, k, v)
+            setattr(args, self.dest, d)
+
+    @staticmethod
+    def set_dict_path_value(obj, key, value):
+        root_obj = obj
+        keys = key.split('.')
+        latest = keys.pop()
+        for k in keys:
+            obj[k] = obj.get(k, {})
+            obj = obj[k]
+        latest_key, *value_type = latest.split(':')
+        value_type = value_type[0] if len(value_type) > 0 else None
+        if value_type is None or value_type == "str":
+            value = value
+        elif value_type == "int":
+            value = int(value)
+        elif value_type == "float":
+            value = float(value)
+        elif value_type == "bool":
+            if value == "True" or value == "true" or value == "1":
+                value = True
+            elif value == "False" or value == "false" or value == "0":
+                value = False
+            else:
+                raise ArgumentTypeError(f"Argument '{key}' has unknown value '{value}'. Must be (true|false|True|False|1|0)")
+        else:
+            raise Exception(f"Unsupported arg type '{value_type}'")
+        obj[latest_key] = value
+        return root_obj
+
+
 # List of available command line options
 AVAILABLE_CLI_OPTIONS = {
     # Common options
@@ -530,4 +575,12 @@ AVAILABLE_CLI_OPTIONS = {
         help='Do not print epoch details header.',
         action='store_true',
     ),
-}
+    "cfg": Arg(
+        '--cfg',
+        nargs='+',
+        metavar="KEY=VALUE",
+        action=SetDictFromArgAction,
+        help='Set any config value.',
+        # action='store_const'
+    ),
+}

freqtrade/configuration/configuration.py

@@ -93,6 +93,9 @@ class Configuration:
         # Load all configs
         config: Dict[str, Any] = self.load_from_files(self.args.get("config", []))
 
+        if 'cfg' in self.args:
+            config = deep_merge_dicts(self.args['cfg'] or {}, config)
+
         # Keep a copy of the original configuration file
         config['original_config'] = deepcopy(config)
 

tests/commands/test_commands.py

@@ -35,6 +35,30 @@ def test_setup_utils_configuration():
     assert config['exchange']['secret'] == ''
 
 
+def test_cfg_argument_replaces_configuration():
+    args = [
+        'list-exchanges', '--config', 'config_bittrex.json.example',
+    ]
+
+    # Check original config
+    config = setup_utils_configuration(get_args(args), RunMode.OTHER)
+    assert config['dry_run'] is True
+    assert config['exchange']['key'] == ''
+    assert config['stake_amount'] == 0.05
+    assert config['timeframe'] == '5m'
+
+    args = [
+        'list-exchanges', '--config', 'config_bittrex.json.example',
+        '--cfg', 'stake_amount:float=0.1', 'timeframe=15m', 'exchange.sandbox:bool=true',
+    ]
+
+    # Check original config
+    config = setup_utils_configuration(get_args(args), RunMode.OTHER)
+    assert config['stake_amount'] == 0.1
+    assert config['timeframe'] == '15m'
+    assert config['exchange']['sandbox'] is True
+
+
 def test_start_trading_fail(mocker, caplog):
 
     mocker.patch("freqtrade.worker.Worker.run", MagicMock(side_effect=OperationalException))