BitTorrent Sync on QNAP NAS devices

This REAMDE explains how to install BitTorrent Sync on your QNAP NAS device by first building QPKG packages, which can then be installed using the QPKG Center application.

Compatible Devices

TS-219P
TS-259Pro (see this forum post and the troubleshooting section)
TS-269L
TS-412
TS-420
TS-469L

The following instructions should work for a wide range of QNAP NAS devices. If a device is missing, I just have not tested it or heard from users about it. Please try and post your results to the BitTorrent forum thread or make a pull request.

Instructions

In order to build the packages, you will need to have QDK installed on your NAS. Download the QDK distribution, unzip it and install it using QPKG Center.

The next step is to figure out which working directory you are going to use for the packaging process. /tmp and /root may not be sufficiently large. You should pick a directory that is located on the HDDs. For the QNAP TS-412 at least, /share/Download will work fine. Login to your NAS via ssh and download the files from this repository.

cd /share/Download # Change to the working directory
curl -kL https://github.com/puppe/btsync-qpkg/archive/master.tar.gz | tar -xz
cd btsync-qpkg-master

Note:
Apparently the certificate for the CA of github.com is not installed. Because of that, we tell curl to ignore certificate warnings by using the -k switch. If you are concerned about MITM attacks, you should download the files to your local machine and transfer them via ssh to your NAS.

Before building the packages, you should change the password for the Web UI in file config/btsync.conf. If you want to use a different port for the Web UI, you will have to edit two files. In file qpkg.cfg, change the variable QPKG_WEB_PORT. In file config/btsync.conf, edit the line that says "listen" : "0.0.0.0:14859".

You are now ready to execute ./make.sh. This will download BitTorrent Sync and then build the packages using qbuild. Once the script has terminated, you should find the QPKG files in the build subdirectory. Copy these to your local machine and install the appropriate package for your architecture via QPKG Center. After installing, you can start BitTorrent Sync from QPKG Center.

If you want to change the configuration of BitTorrent Sync after installing it, you can edit btsync.conf. At least for my device and setup, this file can be found in /share/MD0_DATA/.qpkg/BitTorrentSync/.

If you have any questions, ask them in the BitTorrent forum thread or file an issue. Pull requests are always welcome!

Troubleshooting

Error upon executing ./make.sh

Problem:
You get the following error when you execute ./make.sh

./make.sh: /usr/bin/qbuild: /bin/bash: bad interpreter: No such file or directory

Solution:
Create a symbolic link that points to /bin/sh, then try again, and finally remove the link.

ln -s /bin/sh /bin/bash
./make.sh
rm /bin/bash

Thanks to bakanach!

Thanks

Parts of the init script are taken from Bittorrent forum user sitnin's init script.