permit overriding config filename/path as argument

src/capport/config.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import dataclasses
 import os.path
+import sys
 import typing
 
 import yaml
@@ -30,6 +31,10 @@ class Config:
     @staticmethod
     def load(filename: typing.Optional[str] = None) -> Config:
         if filename is None:
+            if len(sys.argv) > 0:
+                for name in sys.argv[1:]:
+                    if os.path.exists(name):
+                        return Config.load(name)
             for name in ('capport.yaml', '/etc/capport.yaml'):
                 if os.path.exists(name):
                     return Config.load(name)