Ralf provides an HTTP API that both Bono and Sprout can use to report billable events that should be passed to the CDF (Charging Data Function) over the Rf billing interface. Ralf uses a cluster of Memcached instances and a cluster of Chronos instances to store and manage session state, allowing it to conform to the Rf protocol.
Note: This is my attempt to build the container - but I recommend using docker-compose to orchestrate and put everything together. Check out - https://github.com/Metaswitch/clearwater-docker
Thanks Project Clearwater team.