We have an application (App 'A') that runs on multiple nodes behind a load balancer.
The App sends API requests to another application (App 'B') which currently only accepts API requests from a single IP address. Because App 'A's outbound IP address changes depending on which node the request is sent from, App 'B' cannot authenticate it due to its single API access IP configuration limitation.
Is it possible to set up a proxy server to catch all API requests from App 'A' (regardless of IP address or a set IP Range, or netblock) and forward them to App 'B' via its own static IP?
If so which server/software is best suited to this purpose?