How can I dump nginx requests for a specific location while nginx is secured?

Question

I want to dump all request that nginx is getting for a specific location so I can debug a strange problem that I have.

Usually tcpdump would be the solution but remember that nginx is accessed using HTTPS so dumping secured packages wouldn't be useful.

Note: in fact I am mostly intereted to dump all headers as I need to find out if any proxy modified the requests made by the client.

Obviously, I already used Wireshark or Charles on the client side but I came to the conclusion that that reaches the server is different that what it was sent by the client.

Depending on your encryption you can decrypt the ssl traffix with wirshark if you have access to the ssl key. This works with RSA. — Christopher Perrin, Aug 05 '13 at 18:12
Thanks @ChristopherPerrin ... I was hopping for something easier than this, especially that I can control the NGINX which is used only as a frontend to another webserver. — sorin, Aug 05 '13 at 18:19

score 0 · Answer 1 · answered Aug 05 '13 at 18:29

You can but only for predefined headers. With a combination of the nginx geo module and a custom log format.

geo $geo  {
  default          0;
  127.0.0.1/32     1;
  192.168.1.0/24   1;
  10.1.0.0/16      1;
}

server {
  log_format custom '$remote_addr - HEADERS: $sent_http_content_range';

  if($geo) {
    access_log bad.log custom;
  }
}

How can I dump nginx requests for a specific location while nginx is secured?

1 Answers1