Apolitically Incorrect » Installing Duplicity on Mac OS X

While Mac OS X shares many things in common with other Unix operating systems, it also has a couple of missing parts. This can make installing software more difficult when compared to Linux or other *nix variants, and unfortunately, Duplicity happens to be one of those cases.

But just because it is more difficult to install Duplicity on Mac doesn’t mean that it isn’t worthwhile. Duplicity is one of the best command line backup programs available anywhere. Using the same program, you can backup to a local hard drive, FTP server, over SSH or even to Amazon S3. It uses the rsync algorithm, which means that backups happen quickly and only the parts of files that actually changed get copied. Subsequently, backups are smaller.

Nor does it mean that installing Duplicity is actually all that hard, it’s just a bit tedious. Like many other *nix programs, Duplicity requires a number of additional programs (called dependencies) that you will have to search out and install separately. To make that process easier, this article explains how. Below, you’ll find links to the download pages and instructions for how to compile each of Duplicity’s dependencies on Mac OS X. The instruction set has been tested both on Mac OS X 10.5 (Leopard) and Mac OS X 10.6 (Snow Leopard).

XCode

The first dependency you will need is a rather large one. Several of the software packages need to be compiled from source. But unfortunately, Mac OS X doesn’t install the compilers by default. Thus, you will either need to install them from the Mac OS X installation CD, or by getting the XCode tools from the Apple Developer Connection (ADC). Note: ADC requires that you have an Apple ID – which is free – to log in into the site.

After you log-in, download the XCode developer tools package. Once XCode has finished downloading, run the package installer. It will ask you to select the destination drive and what components of the software you would like to install.

Select the installation disc where you want to install XCode the developer tools

Choose the Develoepr Tools Essentials, System Tools and Unix Development Support options. This will automatically install and configure the GNU tool chain and the GCC compiler collection. Once it has finished, you can access the tools by going to the “/Developer/” folder on the root of the drive.

After XCode is finished installing you are ready to build and install the other necessary dependencies.

Note: All other steps in this tutorial will be run from the command line terminal.

GnuPG

GnuPG handles the encryption and decryption of tar archive files. If it isn’t installed and configured correctly, Duplicity (and by extension) Time Drive simply won’t work. On Linux and other Unix operating systems, GnuPG is typically included as part of the default installation. This is not true on Mac OS X, however. As a result, you will need to download, compile and install it from source.

You can find the source files on the project download page or the associated ftp site. Duplicity will work with version GnuPG version 1.4 or 2.0. The biggest difference between the two is that version 2.0 is slightly more modular, and as a result, has a speed advantage. From a practical standpoint, however, unless you are running large, frequent backups, you are not likely to notice any difference. I have been able to compile both without any difficulty on both Leopard and Snow Leopard, so the choice is largely one of preference.

After downloading the most recent version, extract the archive by typing:

tar –xf gnupg-x.x.x.tar.gz2

Where x.x.x is the version of GnuPG that you downloaded (at the time of this writing, it is version 2.0.12). This will create a new directory called gnupg-2.0.12. From that directory, you can configure, compile, test and install:

cd gnupg-2.0.12
./configure
make; sudo make install

When finished, return to the working directory by typing:

cd ..

GnuPG Interface – Python Module

Now that you have built and installed GnuPG, you will next need to install the Python bindings so that duplicity can make use it. You can get these from the GnuPG Interface Module project page, specifically from the download section. Grab the most recent version (0.3.2). To install, extract the folder, enter the setup directory and then use python to run the “setup.py” script:

tar -xf GnuPGInterface-0.3.2.tar.gz
cd GnuPGInterface-0.3.2
sudo python setup.py install

NcFTP

NetworkArchive5 NcFTP enables Duplicity to make backups to FTP servers. The download files can be found on NcFTP’s download page, which lists both the NcFTPd Server and the NcFTP client. We want the most recent version of the client source code (version 3.2.3).

Like GnuPG, we need to configure, compile and install:

tar –xf ncftp-3.2.3-src.tar.bz2
cd ncftp-3.2.3
./configure
make; sudo make install

Boto – Amazon S3 Support

To use Amazon as a backup destination, you need to grab the Boto python module. Boto provides a structured and integrated interface to most of the features offered by Amazon Web services, most importantly: the Simple Storage Service (S3). You can get the most recent version (1.8d) from the Boto downloads page on Google Code.

From there, the installation procedure is similar to that for the GnuPG python interface module. Extract the archive, enter the program folder and use python to run the setup script.

tar -xf boto-1.8d.tar.gz
cd boto-1.8d
sudo python setup.py install

Duplicity

Once you have installed GnuPG, the GnuPG python interface, NcFTP and Boto, you are ready to install Duplicity. Because it is a python program, the steps are identical to those of Boto and the GnuPG python interface. Download the source code from the project home page (keeping in mind that Time Drive requires at least version 0.6.04); then, extract it the same way that you did the previous libraries and enter the source code directory: