Docker Image for QTS

This repository contains a Dockerfile for building a Docker image for QTS, the operating system running on QNAP NAS products. It's useful for developing for QTS without having to install the development tools directly on your NAS.

This repository does not contain the actual root filesystem. It's easily extracted from a running QTS system.

This Dockerfile has been tested on a root filesystem from a 64bit QNAP NAS running QTS 4.2.2.

Building the Image

Prerequisites

A QNAP NAS running the version of QTS you want to build a Docker image for

Building

Make sure SSH is enabled on the NAS
Login on the NAS using SSH
Execute the following command to bundle the root filesystem in a TAR archive:
```
tar --numeric-owner --exclude=/proc --exclude=/sys --exclude=/share -cvf rootfs.tar /
```
We're excluding /share since there is where all the hard drives are mounted
Copy the newly created TAR file to your local machine using SCP
Clone this repository
Put the TAR file in the res directory, it needs to be called rootfs.tar
Run ./build.sh to build the Docker image
After the Docker image is built it should be available under the name qts

Developing in the Docker container

To develop in the Docker container install the QTS developer tools (QDK) and/or install the Entware-ng package manager, which contains most of the common Posix development tools, like GCC.

Installing QPKG Packages

A QPKG package consist of a shell script containing a form of startup script and the binary data for the rest of the package. Since QPKG packages are regular shell scripts they can be easily installed by just executing the shell script.

Unfortunately there's a caveat when it comes to installing QPKG packages inside a Docker container. In the beginning of a QPKG package there's a piece of code looking something like this:

/bin/grep "/mnt/HDA_ROOT" /proc/mounts >/dev/null 2>&1 || exit 1

This command checks if a filesystem is mounted to /mnt/HDA_ROOT. This check will fail inside a Docker container. One way to workaround this is to modify the QPKG package (using vim or similar) and comment out that line. If that line is commented out there's another line that needs to be updated, a line looking something like this: script_len=724. That value needs to be updated to match the number of characters in the package before the binary data begins. So if # is added to the above line to comment it out, increment the script_len variable with 1.