How to use NGINX as forward proxy for any requested location?

Question

I am trying to configure NGINX as a forward proxy to replace Fiddler which we are using as a forward proxy. The feature of Fiddler that we use allows us to proxy ALL incoming request to a 8888 port. How do I do that with NGINX?

In all examples of NGINX as a reverse proxy I see proxy_pass always defined to a specific upstream/proxied server. How can I configure it so it goes to the requested server, regardless of the server in the same way I am using Fiddler as a forward proxy.

Example:

In my code:

WebProxy proxyObject = new WebProxy("http://mynginxproxyserver:8888/",true);
WebRequest req = WebRequest.Create("http://www.contoso.com");
req.Proxy = proxyObject;

In mynginxproxyserver/nginx.conf I do not want to delegate the proxying to another server (e.g. proxy_pass set to http://someotherproxyserver). Instead I want it to just be a proxy server, and redirect requests from my client (see above) to the request host. That's what Fiddler does when you enable it as a proxy: http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/UseFiddlerAsReverseProxy

Answer 1

You can run into url encoding problems when using the $uri variable as suggested by Grumpy, since it is decoded automatically by nginx. I'd suggest you modify the proxy pass line to

proxy_pass http://$http_host$request_uri;

The variable $request_uri leaves the encoding in tact and also contains all query parameters.