Sink configuration

Sink configuration is also Json map string whose key is the id of the sink and the value is sink configuration.

Example with two S3FileSinks

{
    "default": {
        "type": "S3FileSink",
        "localFileSink": {
            "type": "LocalFileSink",
            "outputDir": "/mnt/data/suroServer/fileSink1",
            "bucket": "fileSink1"
        }
    },
   "anotherFileSink": {
        "type": "S3FileSink",
        "localFileSink": {
            "type": "LocalFileSink",
            "outputDir": "/mnt/data/suroServer/fileSink2",
            "bucket": "fileSink2"
        }
    }
}

There should be at least one sink with the 'default' as id. If there's no 'default' sink, suro server would not start with an error message saying "default sink should be defined". If the data source is not registered in the routing map, all messages with unregistered topic would be sent through 'default' sink.