Help on creating that flow that requires processing attributes in a flow content but need to preserve the original flow content

[McDermott, Chris Kevin (MSDU - STaTS/StorefrontRemote)]

What I need to do is read a file from Kafka.  The Kafka key contains a JSON 
string which I need to turn in FlowFile attributes while preserving the 
original FlowFile content.  Obviously I can use EvaluteJsonPath but that 
necessitates replacing the FlowFile content with the kaka.key attribute, thus 
loosing the original FlowFile content.  I feel like I’m missing something 
fundamental.