Ibexpair is a simple Linux command-line utility for pairing your second-generation Steam Controller with your puck without needing Steam.
Simply place your powered-off Steam Controller on your puck and run the command. It will automatically pair to the first slot on both.
You can specify the slot used on puck with -p 1-4 and
the controller with -c 1-2.
The program needs access to hidraw. The udev rules created by Valve,
usually provided by distros in steam-devices package, should suffice.
Running as root will also work.
All you need is make, gcc, linux-headers and libudev.
Simply run make.