13.6. OpenLDAP Setup Overview
This section provides a quick overview for installing and configuring an OpenLDAP directory. For more details, refer to the following URLs:
http://www.openldap.org/doc/admin/quickstart.html — The Quick-Start Guide on the OpenLDAP website.
http://www.redhat.com/mirrors/LDP/HOWTO/LDAP-HOWTO.html — The LDAP Linux HOWTO from the Linux Documentation Project, mirrored on Red Hat's website.
The basic steps for creating an LDAP server are as follows:
Install the openldap, openldap-servers, and openldap-clients RPMs.
Edit the /etc/openldap/slapd.conf file to reference your LDAP domain and server. Refer to Section 13.6.1 Editing /etc/openldap/slapd.conf for more information on how to edit this file.
Start slapd with the command:
/sbin/service/ldap start
After you have configured LDAP correctly, you can use chkconfig, ntsysv, or the Services Configuration Tool to configure LDAP to start at boot time. For more information about configuring services, refer to the chapter titled Controlling Access to Services in the Red Hat Linux Customization Guide.
Add entries to your LDAP directory with ldapadd.
Use ldapsearch to see if slapd is accessing the information correctly.
At this point, your LDAP directory should be functioning properly and you can configure any LDAP-enabled applications to use the LDAP directory.
13.6.1. Editing /etc/openldap/slapd.conf
In order to use the slapd LDAP server, you will need to modify its configuration file, /etc/openldap/slapd.conf. You must edit this file to specify the correct domain and server.
The suffix line names the domain for which the LDAP server will provide information and should be changed from:
suffix "dc=your-domain,dc=com" |
so that it reflects a fully qualified domain name. For example:
suffix "dc=example,dc=com" |
The rootdn entry is the Distinguished Name (DN) for a user who is unrestricted by access controls or administrative limit parameters set for operations on the LDAP directory. The rootdn user can be thought of as the root user for the LDAP directory. In the configuration file, change the rootdn line from its default value to something like the example below:
rootdn "cn=root,dc=example,dc=com" |
If you intend to populate the LDAP directory over the network, change the rootpw line — replacing the default value with an encrypted password string. To create an encrypted password string, type the following command:
slappasswd |
You will be prompted to type and then re-type a password, then the program prints the resulting encrypted password to the terminal.
Next, copy the newly created encrypted password into the /etc/openldap/slapd.conf on one of the rootpw lines and remove the hash mark (#).
When finished, the line should look similar to the following example:
rootpw {SSHA}vv2y+i6V6esazrIv70xSSnNAJE18bb2u |
 | Warning |
|---|---|
LDAP passwords, including the rootpw directive specified in /etc/openldap/slapd.conf, are sent over the network in unencrypted, unless you enable TLS encryption. To enable TLS encryption review the comments in /etc/openldap/slapd.conf and see the man page for slapd.conf. |
For added security, the rootpw directive should be commented out after populating the LDAP directory by preceding it with a hash mark (#).
When using the /usr/sbin/slapadd command line tool locally to populate the LDAP directory, use of the rootpw directive is not necessary.
 | Important | |
|---|---|---|
You must be the root user to use /usr/sbin/slapadd. However, the directory server runs as the ldap user. Therefore the directory server will not be able to modify any files created by slapadd. To correct this issue, after you have finished using slapadd, type the following command:
|