Support online railway deployment

config.py

@@ -10,11 +10,18 @@ def load_config():
     global config
     config_path = "./config.json"
     if not os.path.exists(config_path):
-        raise Exception('配置文件不存在，请根据config-template.json模板创建config.json文件')
+        logger.info('配置文件不存在，将使用config-template.json模板')
+        config_path = "./config-template.json"
 
     config_str = read_file(config_path)
     # 将json字符串反序列化为dict类型
     config = json.loads(config_str)
+
+    # override config with environment variables.
+    # Some online deployment platforms (e.g. Railway) deploy project from github directly. So you shouldn't put your secrets like api key in a config file, instead use environment variables to override the default config.
+    for name, value in os.environ.items():
+        config[name] = value
+
     logger.info("[INIT] load config: {}".format(config))