I've configured NGINX load balancing for my application with two upstream servers using IP_Hash, which is working fine. My application also receives POST requests from our internal service endpoint.
The user connects to NGINX, through which the HTTP requests are sent to one of the upstream servers, A. Upstream server A also communicates with our internal service endpoint for updating a resource—a POST request is sent from that endpoint.
The problem now is that the DNS record on AD is set up with NGINX's IP address for the endpoint to communicate with, so there is a chance that the endpoint sends the POST request to upstream server B.
Is there a way we can force the internal service endpoint to send the POST request to upstream server A?
thanks!
Internal Service Endpoint only respond to the Upstream Server that initiate the request.