Open Directory is the Mac OS X native directory service. Made up of a collection of technologies (many of them open source), Open Directory manages user, group, and computer records for local accounts on a specific Mac as well as network accounts hosted by a server.
The bones of a network infrastructure, Open Directory accomplishes such complex and diverse tasks as securely authenticating users based on name and password (or alternate authentication method), authorizing access to resources, and providing a managed client experience.
In part 1 of this series, we looked at the significant changes made in Leopard to local Open Directory information (primarily the retirement of NetInfo as a repository for local account information). In this article, we’ll take a brief look at some of the changes made to Open Directory in Leopard Server.
This article assumes at least a basic understanding of the concepts and principles on which Open Directory is based. Novice server administrators or technicians may want to review the following articles for a larger overview of Open Directory and how it was implemented in earlier versions of Mac OS X Server:
- "How-to: Understanding Mac OS X Open Directory"
- "So You Want to Be a Mac OS X Server Admin? Understanding the Building Blocks of Open Directory and Mac OS X User Management"
Updated OpenLDAP Version
One of the most basic underpinnings of Open Directory is OpenLDAP, the open source LDAP solution that Open Directory relies on to store and retrieve information. Open Directory 4, which is included with Leopard Server includes a more recent version (2.3.x) of OpenLDAP.
In addition to various improvements over the OpenLDAP versions used with previous Open Directory releases, OpenLDAP 2.2 introduced the capability to store modifications to its standard LDAP configuration as a series of overlays instead of direct code changes. This is significant because Apple makes a number of changes to the standard OpenLDAP implementation as part of Open Directory.
Those code modifications have, in the past, made it problematic for engineers to upgrade OpenLDAP on Mac OS X Server to take advantage of new features.
Using overlays mitigates many of these issues, making the OpenLDAP elements of Open Directory more flexible and easier to upgrade.