nginx_md5_filter

A content filter for nginx, which returns the md5 hash of the content otherwise returned.

Installation

As with all nginx modules, this must be built into the executable. Here's a simple example building and installing nginx with this module (I use v1.4.4 only so the example would actually work instead of 1.4.x)

wget 'http://nginx.org/download/nginx-1.4.4.tar.gz' #or using the latest version
tar -xzvf nginx-1.4.4.tar.gz
cd nginx-1.4.4

./configure --add-module=/path/to/nginx_md5_filter
make
make install

Usage

Currently this module has an extremely simple config file language.

location /hash {
    md5_filter on;
    proxy_pass @content;
}

Future versions, I plan on implementing a request header flag to enable/disable the filter, removing the need for a hash location.

Output

When activated, in place of the content that would be served, the body will be replaced by the 32byte hexdigest of the content (similar to the linux cmd md5sum). Additionally, a X-Content-Length header will be set to the original Content-Length.