C H A P T E R 1

Concepts

Figure 1-1Flow of an Open Directory request

Open Directory client

DirectoryServices daemon

Open Directory plug-ins

Request

Response

The Open Directory programming interface identifies the basic features that are common to many directory services and provides the functions necessary to support the development of high-quality applications that can work with a wide range of dissimilar directory services.

Nodes

From the viewpoint of Open Directory, a directory service is a collection of one or more nodes, where a node is a place that can be searched for information. Each NetInfo database in a hierarchy and each LDAP service configured by the Directory Access tool is a separate node. The following rules apply to nodes.

A node is either the root of a directory or a child of another node.

A registered node is a node that an Open Directory plug-in has registered with Open Directory or that an administrator has registered using the Directory Access tool.

A node is a collection of records and child nodes.

A record can belong only to one node.

A record has a type and can be of no more than one type. Examples of record types include user records and group records.

A record has a name and type that together make the record unique within its node. For example, there can’t be two user records that have the name “admin,” but there can be a user record named “admin” and a group record named “admin” within the same node.

Nodes and records can contain any number of attributes.

An attribute can have a value. Certain attributes can have more than one value.

An attribute value is arbitrary data whose structure is unknown to the Open Directory programming interface. Open Directory clients are responsible for interpreting the value of any particular attribute.

Figure 1-2(page 11) shows how Open Directory and the Open Directory LDAPv3 and NetInfo plug-ins might locate nodes over a network.

10Open Directory Overview

2007-01-08 © 2007 Apple Inc. All Rights Reserved.

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Apple OS X manual Nodes, 1Flow of an Open Directory request