Install OpenLDAP Server

Install Stand-Alone LDAP Daemon:

sudo apt install slapd ldap-utils

Set a password for the admin entry in the LDAP directory

Check out status of slapd

systemctl status slapd

Basic Post-Installation Configuration:

sudo dpkg-reconfigure slapd

Omit LDAP server configuration: NO
DNS domain name: Enter your domain name: testlab.com
Organization name: TestLab
Administrator password: Enter the same password set during installation
Database backend: MDB:
   BDB (Berkeley Database) is slow and cumbersome. It is deprecated and support will be dropped in future OpenLDAP releases. 
   HDB (Hierarchical Database) is a variant of the BDB backend and will also be deprecated.
   MDB reads are 5-20x faster than BDB. Writes are 2-5x faster. And it consumes 1/4 as much RAM as BDB.
Do you want the database to be removed when slapd is purged? No
Move old database? Yes
Allow LDAPv2 protocol? No
   The latest version of LDAP is LDAP v.3, developed in 1997. LDAPv2 is obsolete.

Configuring the LDAP Clients:

sudo nano /etc/ldap/ldap.conf

Need to specify two parameters:

Base DN 
URI of our OpenLDAP server

Copy and paste the following text at the end of the file:

BASE     dc=testlab,dc=com
URI      ldap://localhost

If you used a subdomain when configuring OpenLDAP server, then you need to add the subdomain here like so

BASE      dc=subdomain,dc=testlab,dc=com
ldap://localhost

Testing OpenLDAP Server:

ldapsearch -x

Indicates that OpenLDAP server is working:

Result: 0 Success

If you get the following line, then it’s not working:

result: 32 No such object

phpLDAPadmin

sudo apt install phpldapadmin
sudo nano /etc/phpldapadmin/config.php

LDAP

Install OpenLDAP Server

phpLDAPadmin

StartTLS LDAP Encryption