nginx

Configuring NGINX to log HTTP POST data on Linux / RHEL

By Bachir Chihani May 23, 2016October 18, 2018

NGINX is a powerful web server that can easily handle high volumes of HTTP traffic. Each time NGINX handles a connection, a log entry is generated to store some information this connection like remote IP address, response size and status code, etc. The complete set of logged information with more details can be found here.

In some cases, you may be more interested in storing the body of requests, specifically POST requests. Lucky, the NGINX ecosystem is rich, and includes quite a few handy modules. One such module is the Echo module, which provides useful functionality for things like: echo, time, and sleep commands.

In our use case, to log a request body, what we need is to use the echo_read_request_body command and the $request_body variable (contains the request body of the Echo module). However, this module is not distributed with NGINX by default, and to be able to use it we have to build NGINX from its source code by building it with the source code of the Echo module included.