How to Install OpenLDAP on Ubuntu 24.04

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Introduction

OpenLDAP is a free and open-source implementation of the Lightweight Directory Access Protocol (LDAP). It provides a centralized directory service for storing user accounts, passwords, group information, and other directory data.

In this tutorial, we will install OpenLDAP on Ubuntu 24.04, configure phpLDAPadmin, create a basic LDAP structure, add a test user, and enable HTTPS with Let’s Encrypt.

Note: The domain example.com is used for demonstration purposes. Replace it with your own domain when following this guide.

Prerequisites

Before starting, you should have:

Ubuntu 24.04
Root or sudo access
A domain pointing to your server

For this tutorial:

Domain: example.com
Base DN: dc=example,dc=com
Administrator DN: cn=admin,dc=example,dc=com

Create a Server Instance

Provision a clean Ubuntu 24.04 server with at least 2 CPUs, 2 GB RAM, and 20 GB SSD.

After deployment, note the server IP address.

Connect to Your Server via SSH

On Linux or macOS:

ssh root@your_server_ip

On Windows, use an SSH client such as PuTTY and connect as root.

Step 1: Update the System

apt update && apt upgrade -y

Step 2: Install OpenLDAP Server

Install OpenLDAP and the LDAP utilities:

apt install slapd ldap-utils -y

If the configuration wizard does not appear:

dpkg-reconfigure slapd

During reconfiguration, choose:

Omit OpenLDAP server configuration? → No
DNS domain name: example.com
Organization name: Example Inc
Admin password: choose a secure password
Database backend: MDB
Remove database when slapd is purged? → No
Move old database? → Yes

The resulting Base DN is:

dc=example,dc=com

Step 3: Verify LDAP Server

Check the service:

systemctl status slapd

Test the LDAP server:

ldapsearch -x -LLL -b dc=example,dc=com

Step 4: Install phpLDAPadmin

Install phpLDAPadmin:

apt install phpldapadmin -y

Edit the configuration:

nano /etc/phpldapadmin/config.php

Update:

$servers->setValue('server','host','127.0.0.1');
$servers->setValue('login','bind_id','cn=admin,dc=example,dc=com');

Edit the Apache configuration:

nano /etc/apache2/conf-enabled/phpldapadmin.conf

Change:

Require local

to:

Require all granted

Restart Apache:

systemctl restart apache2

phpLDAPadmin can now be accessed through:

http://your_server_ip/phpldapadmin/

or, after DNS propagation:

http://example.com/phpldapadmin/

Step 5: Create Base LDAP Structure

Create the LDIF file:

nano base.ldif

Add:

dn: ou=people,dc=example,dc=com
objectClass: organizationalUnit
ou: people

dn: ou=groups,dc=example,dc=com
objectClass: organizationalUnit
ou: groups

Import the structure:

ldapadd -x -D cn=admin,dc=example,dc=com -W -f base.ldif

Step 6: Add an LDAP User

Create the user file:

nano john.ldif

Add:

dn: uid=john,ou=people,dc=example,dc=com
objectClass: inetOrgPerson
sn: Doe
givenName: John
cn: John Doe
uid: john
mail: [email protected]
userPassword: password

For production environments, use a strong password.

Generate a password hash with:

slappasswd

Then add the user:

ldapadd -x -D cn=admin,dc=example,dc=com -W -f john.ldif

Step 7: Enable HTTPS with Let’s Encrypt

Install Certbot:

apt install certbot python3-certbot-apache -y

Request an SSL certificate:

certbot --apache -d example.com

Choose the option to redirect HTTP traffic to HTTPS.

Final Access Points

phpLDAPadmin:

https://example.com/phpldapadmin/

Test LDAP:

ldapsearch -x -LLL -b dc=example,dc=com

The LDAP user created in this tutorial is:

uid=john,ou=people,dc=example,dc=com

Conclusion

OpenLDAP is now installed and configured on Ubuntu 24.04 with phpLDAPadmin, a basic LDAP directory structure, an LDAP user, and HTTPS enabled.

This setup can be used as a centralized LDAP directory for applications and services that support LDAP authentication.