The OS X file sharing in the Finder is so beautifully designed that I just had to make our new Ubuntu file server integrate cleanly with Finder. This turned out to be a fairly painful process, without any clear documentation, so here’s a tutorial:

Background:

OS X file sharing is done with AFP (AppleTalk Filing Protocol) and Bonjour (zeroconf) style service discovery. AFP allows one Mac to connect to another’s shares, while Bonjour handles the auto-discovery of available shares.

Packages required:

netatalk - This package contains an implementation of AFP.
avahi - This package performs the Bonjour style service publishing to make it easy for other Macs to discover the share.

These packages are not in the standard distribution, so you have to enable the “universe” repository by editing /etc/apt/sources.list. This is documented here.

sudo apt-get update (update the system’s knowledge of available packages)

The standard installation of netatalk cannot handle encrypted logins, which means OS X will pop up an annoying warning about cleartext passwords. For this reason, the following instructions are provided to build and install the netatalk package from source.

sudo apt-get install devscripts (installs debuild)
apt-get source netatalk
sudo apt-get build-dep netatalk
sudo apt-get install cracklib2-dev
cd netatalk-2.0.3
DEB_BUILD_OPTIONS=ssl debuild (no quotes)
sudo dpkg -i ../netatalk_*.deb

Configuration:

netatalk:

To share your home directories, add the following line to /etc/netatalk/AppleVolumes.default:

~ “$u - Home Directory”

To run netatalk on system startup:

cd /etc/rc2.d
ln -s ../init.d/netatalk S96netatalk

avahi:

Create a /etc/avahi/services/afpd.service file as described on this page.

   %h  _afpovertcp._tcp 548
]]-->

To run avahi on system startup:

cd /etc/rc2.d
ln -s ../init.d/avahi S97avahi

Testing

Either reboot to start the services, or run them like this:

sudo /etc/init.d/netatalk start
sudo /etc/init.d/avahi start

Now pull up your trusty Mac and try to access your home directory on the Linux box via the Network section of Finder. It should look and behave exactly like an OS X share.