title: How to conditionally forward messages between two bridged MQTT broker?
body: <p>I have a MQTT Broker (mosquitto) located at site A and another broker (mosquitto  or RabbitMQ) at cloud. In order for data to be forwarded to cloud, I plan to bridged them and TLS-ed for data security.  </p>
  
  <ol>
  <li><p>At site A, software are communicate internally through MQTT and I DO NOT wish sensitive data be send to the cloud. (e.g: topic with "user/password")  </p></li>
  <li><p>Non-sensitive information such as "user/age", "user/gender" is send to cloud for statistical analysis.  </p></li>
  </ol>
  
  <p>How to configure broker at site A to bridged and conditionally only forward certain topic/message to the cloud broker (while maintaining internal messaging)?  </p>