I developed a Nginx dynamic module and did required configuration in nginx.conf. Able to run that module and see it doing processing. This module reads request request header, cookies etc., does some business logic execution and modify response header then send back response to client.

Problem -: "How to use nginx module when proxying connections to application servers"
I'm be using Nginx as proxy server and Tomcat or Node as application server and my application hosted on app server. I'm able to route the request through both web & app server and get response back but module isn't getting invoked. Not sure how to link/configure it so that my able to intercept request and modify response header as per need.

Browser <-> Web Server (module sits here) <-> Application Server

Has anybody explored this part? If yes then please help. Let me know if more detail needed.