I’ve attempted this a lot of times. Now it works (sort of, but it still needs some tweaking). What you’ll need is a Debian server running a slapd daemon. You can get this with apt-get, of course… It could be handy to have the utils too and I use the GPL-ed handy web based ldap management tool phpldapadmin. I like it, it’s small and easy to work with… So the apt-get command should be like;

apt-get install slapd ldap-utils phpldapadmin

Now after you’ve configured your slapd and phpldapadmin you should be able to login into your ldap server. I used phpldapadmin for that. Remember that you’ll have to use the DN you’ve configured earlier. It look something like ‘cn=admin,dc=subdomain,dc=domain,dc=com’. Yes it’s the complete string, not only ‘admin’!

Now go to addressbookserver.com and download the latest version of ABxLDAP (AddressBook X LDAP), I’ve used for this how to ‘ABxLDAP_v1.1.16_31_May_2008.dmg’.

After you’ve installed it, check the mounted disk image. You should have a file called ‘abxldap.schema‘, it can be found in the folder ‘LDAP Schema Extension’. This file should be uploaded and placed into ‘/etc/ldap/schema’ on your Debian server. Edit your /etc/ldap/slapd.conf and add the schema with this include line;

include         /etc/ldap/schema/abxldap.schema

Now restart the ldap server…

/etc/init.d/slapd restart

Now comes the magic… You’ll have to populate the ldap directory, so ABxLDAP can sync with it… What I did was this:
I’ve made a text file called ‘populate.ldif‘. This file contains the following text:

dn: ou=addressbook,dc=subdomain,dc=domain,dc=com
objectClass: organizationalUnit
ou: addressbook

NOTE: ‘dc=subdomain,dc=domain,dc=com’ should be what ever you’ve configured slapd with in the first step!

Now use phpldapadmin to import the ‘populate.ldif‘ into your ldap directory. When you don’t have any errors, you should be able to sync with ABxLDAP for the first time.

Go to your System Preferences on your Mac and pick the ABxLDAP panel. Fill all the fields. What I use is this:

That’s it, all should be working fine. Every time you edit something in your Address Book on your Mac, it should sync the whole ldap. Also when you delete or edit a record directly on your ldap, it will sync. The only thing I’ve to figure out is, how to sync periodically, so the Mac always have the latest version. Now it only syncs when something is changed in your Address Book, or when you hit the sync button in your ABxLDAP in System Preferences.

Almost forgot to mention. In case of troubleshooting set in slapd.conf loglevel to 448 instead of 0 to get debug log messages in /var/log/syslog.

So more is coming later… Now it’s time for a beer!