Setting failover activemq broker in docker on marathon

Question

I am trying to set up activemq brokers as docker containers (in marathon) using the webcenter/activemq image. I was able to successfully set up a single running container with using the following config env vars in my marathon app definition:

"env": {
        "ACTIVEMQ_CONFIG_MINMEMORY": "1024",
        "ACTIVEMQ_CONFIG_MAXMEMORY": "2048",
        "ACTIVEMQ_CONFIG_NAME": "amq1",
        "ACTIVEMQ_CONFIG_SCHEDULERENABLED": "true",
        "ACTIVEMQ_CONFIG_DEFAULTACCOUNT": "false",
        "ACTIVEMQ_ADMIN_LOGIN": "admin",
        "ACTIVEMQ_ADMIN_PASSWORD": "admin",
        "ACTIVEMQ_USER_LOGIN": "user",
        "ACTIVEMQ_USER_PASSWORD": "user",
        "ACTIVEMQ_ENABLED_AUTH": "false",
        "ACTIVEMQ_ENABLED_SCHEDULER": "true",
        "ACTIVEMQ_LOGLEVEL": "DEBUG"
    }

but I would like to have another broker/container as a failover that can be replaced as the active broker when the current active broker fails. Is there any sort of environment variable that I can pass to set this up. I know of the failover config shown in the documents but I think this would mean that I have to create my own config and mount it to the container in order to set up failover. I would like to know if there are any alternatives to this. Thanks!