The OpenLDAP directory server is a mature product that has been around (in one form or another) since 1995. All of the major Linux distributions include the OpenLDAP server, and many major applications, both Open Source and proprietary, are directory aware, and can make use of the services provided by OpenLDAP. And yet the OpenLDAP server seems to be shrouded in mystery, known and understood only by the gurus and hackers. This book is meant not only to demystify OpenLDAP, but to give the system administrator and software developer a solid understanding of how to make use, in the practical realm, of OpenLDAP’s directory services.

OpenLDAP is an Open Source server that provides network clients with directory services. The directory server can be used to store organizational information in a centralized location, and make this information available to authorized applications. Client applications can connect to OpenLDAP using the Lightweight Directory Access Protocol (LDAP). They can then search the directory and (if they have appropriate access) modify and manipulate records in the directory. LDAP servers are most frequently used to provide network-based authentication services for users. But there are many other uses for an LDAP, including using the directory as an address book, a DNS database, an organizational tool, or even as a network object store for applications. We will look at some of these uses in this book.

The goal of this book is to prepare a system administrator or software developer for building a directory using OpenLDAP, and then employing this directory in the context of the network. To that end, this book will take a practical approach, emphasizing how to get things done. On occasion, we will delve into theoretical aspects of LDAP, but such discussions will only occur where understanding the theory helps us answer practical questions.