Docker Compose嵌套的环境variables

我有一个现有的应用程序使用应用程序configuration文件,如下所示:

"ConnectionInfo": { "ServerName": "The Server URL", "DatabaseName": "The DatabaseName", "UserName": "The User Name", "Password": "The Password"} 

现在,当我有一个简单的设置,说

 "ConnectionString":"My Connection String" 

我知道如何在compose.yml文件中覆盖它:

 environment: - ConnectionString=what I want it to be 

问题是,你如何设置顶部的服务器名称?