Can nginx be configured to allow a path like /api to pass through, and add a header to the request

Question

I am using NGINX as my web server for html/js/css files and my web app UI. It is a single page app that uses AJAX requests to a back end JEtty server. Previously I deployed everything in Jetty and ajax calls worked fine. In separating the back end from the web UI tier, I am now trying to figure out how to configure NGINX to allow AJAX requests to pass through to Jetty. But, I ALSO want to prevent someone from watching network traffic and seeing the ajax calls my app makes, then scripting those themselves. To do this, I believe if I can configure nginx to ADD a custom header to the requests as they pass through (is this even possible?) I could then only accept requests with those headers at my Jetty API level.

If that is possible, is it the right way to handle this so that outsiders can't get in to my back end API? Is there a way they could figure out that my nginx server is adding a header short of breaking in to my server and figuring out the configuration?

Answer 1

If your application calls your api via Ajax on the client there's nothing you can do to stop someone from calling it directly (assuming they otherwise have access to the page). At the end of the day, an Ajax request is just a request made from the client in JS. Now, there are lots of stupid ways to make it more difficult, but, if anyone really wants to call your api directly, they can.

If you're just talking about only allowing access through nginx (or specifically your /api location block), just bind jetty to localhost only.