Allow the xApp writer to simply specify a function/handler to be called when the xApp configuration is updated. The configuration is provided to the xApp as a JSON object and it consists of the "controls" section of the xApp descriptor. In the current version (Cherry) the configuration is stored in the xApp config map and the framework can detect the change using iNotify.
 

Internally this function uses the XAPP_DESCRIPTOR_PATH environment variable to locate the config-file.json file.