Use with

indicator_alertmanager.py

@@ -28,8 +28,7 @@ class Indicator():
         """Initialize idicator."""
 
         # Load config
-        config_file = open(Path.expanduser(config),
-                           encoding="UTF8")  # type:ignore
+        with open(Path.expanduser(config), encoding="UTF8") as config_file:  # type:ignore
             opts = yaml.load(config_file, Loader=yaml.FullLoader)
             self.url = opts.get('url')
             self.port = opts.get('port', 443)