allow reading config from stdin

docs/bot-usage.md

@@ -26,7 +26,8 @@ optional arguments:
   --version             show program's version number and exit
   -c PATH, --config PATH
                         Specify configuration file (default: None). Multiple
-                        --config options may be used.
+                        --config options may be used. Can be set to '-' to
+                        read config from stdin.
   -d PATH, --datadir PATH
                         Path to backtest data.
   -s NAME, --strategy NAME

freqtrade/arguments.py

@@ -85,8 +85,9 @@ class Arguments(object):
         )
         self.parser.add_argument(
             '-c', '--config',
-            help='Specify configuration file (default: %(default)s). '
-                 'Multiple --config options may be used.',
+            help="Specify configuration file (default: %(default)s). "
+                 "Multiple --config options may be used. "
+                 "Can be set to '-' to read config from stdin.",
             dest='config',
             action='append',
             type=str,

freqtrade/configuration.py

@@ -79,6 +79,7 @@ class Configuration(object):
         # Now expecting a list of config filenames here, not a string
         for path in self.args.config:
             logger.info('Using config: %s ...', path)
+
             # Merge config options, overwriting old values
             config = deep_merge_dicts(self._load_config_file(path), config)
 
@@ -118,7 +119,8 @@ class Configuration(object):
         :return: configuration as dictionary
         """
         try:
-            with open(path) as file:
+            # Read config from stdin if requested in the options
+            with open(path) if path != '-' else sys.stdin as file:
                 conf = json.load(file)
         except FileNotFoundError:
             raise OperationalException(