How to use Gatling to create REST API?

I would like to create REST API using gatling. The REST service has POST method call through get the Gatling simulation argument and gatling configuration files and start the Load test when the POST call triggered. Perform load team and respond the result of Gatling report in the REST API. How can I try out this ? I don't have any function to trigger the Gatling in 2.2.5 version. But I found the Gatling 2.2.2 has fromArg method to trigger the Gatling test but I couldn't able to get the result in program. Ii tried with jdbc writer method to write Cassandra, but not working. Any one can help me on this. ?