如何为mongo集群运行db-migrate？

Question

https://db-migrate.readthedocs.io/en/latest/Getting%20Started/usage/

mongo集群的database.json看起来如何？ 这是我当前的配置文件：

{
      "dev": {
        "driver": "mongodb",
        "database": "db",
        "host": "mongo-db"
      }
    }

mqtt群集：

我的3个mongo数据库是

mongo-db1，mongo-db2，mongo-db3

主机可以有3个mongos吗？

{
      "dev": {
        "driver": "mongodb",
        "database": "db",
        "host": "mongo-db1,mongo-db2,mongo-db3"
      }
 }