config: persist CLI configuration

Report the valid command-line configuration options.

Closes: systemd#1993

mkosi/config.py

@@ -3174,8 +3174,10 @@ def finalize_defaults(namespace: argparse.Namespace, defaults: argparse.Namespac
  finalize_defaults(namespace, defaults)
  images = [namespace]
 
+ cli_valid = dict({key: getattr(cli_ns, key) for key in vars(cli_ns)})
  for s in vars(cli_ns):
  if s not in SETTINGS_LOOKUP_BY_DEST:
+ del cli_valid[s]
  continue
 
  if getattr(cli_ns, s) is None:
@@ -3194,6 +3196,14 @@ def finalize_defaults(namespace: argparse.Namespace, defaults: argparse.Namespac
  hint="Prefix the setting with '@' in the image configuration file to allow overriding it from the command line.", # noqa: E501
  )
 
+ commandline=""
+ for key in cli_valid:
+ value = cli_valid[key]
+ commandline+=" --{!s}={!s}".format(key, value)
+
+ if len(commandline) > 0:
+ logging.info(f"CLI: {commandline}")
+
  if not images:
  die("No images defined in mkosi.images/")