This plugin has been developped and tested on GNU/Linux Debian only and against TrafficServer 4.0.2.

Previous ATS versions have not been tested

It makes use of json-c, which is available on Debian Wheezy from backport repository

deb http://ftp.fr.debian.org/debian/ wheezy-backports main non-free contrib
deb-src http://ftp.fr.debian.org/debian/ wheezy-backports main non-free contrib

Some JSON APIs do not always optimize JSON response. Sometime, content is returned formatted and indented in a human-readable way. That's great for debugging, not for production.

When TrafficServer handle a request, it will check HTTP Status and content-type. If content-type is set to application/json and HTTP Status code is 200, then it'll try to load Json body into memory and dump it back without any spaces and/or new line.

A better solution is to use gzip compression, but this comes with a price: cache invalidation in order to load compressed content. Thus, « crushing » JSON representents a cheap optimization and bandwith spare with little efforts.

1. install build dependencies (I assume you already have a build environment)

   apt-get install libjson-c-dev # from Wheezy backport repo
   

2. You have to build trafficserver so that headers files will be available. Build can be done either from source, or you need to install trafficserver-dev package.

3. Finally build JCruncher.

   tsxs -o jcrusher.so -c jcrusher-transform.c -I<PATH_TO_ATS_BUILD>/lib/ts -ljson-c -Ljson-c # If you build ATS from source
   tsxs -o jcrusher.so -c jcrusher-transform.c -ljson-c -Ljson-c # If you installed trafficserver-dev package
   

1. copy jcrusher.so to your ATS server into /usr/lib/trafficserver/modules/

2. install libjson-c on your ATS server

   apt-get install libjson-c2 # from Wheezy backport repo
   

3. add jcrusher.so to /etc/trafficserver/plugin.config

4. restart TrafficServer