OpenLDAP : Replication2023/07/03

	Configure OpenLDAP Replication to continue Directory service if OpenLDAP master server would be down. OpenLDAP master server is called [Provider] and OpenLDAP replication server is called [Consumer] on OpenLDAP.
[1]	Configure Basic LDAP Server settings on both Provider and Consumer, refer to here.
[2]	Configure LDAP Provider. Add syncprov module.

root@dlp:~#

vi mod_syncprov.ldif

# create new

dn: cn=module,cn=config
objectClass: olcModuleList
cn: module
olcModulePath: /usr/lib/ldap
olcModuleLoad: syncprov.la

root@dlp:~#

ldapadd -Y EXTERNAL -H ldapi:/// -f mod_syncprov.ldif

SASL/EXTERNAL authentication started
SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth
SASL SSF: 0
adding new entry "cn=module,cn=config"

root@dlp:~#

vi syncprov.ldif

# create new

dn: olcOverlay=syncprov,olcDatabase={1}mdb,cn=config
objectClass: olcOverlayConfig
objectClass: olcSyncProvConfig
olcOverlay: syncprov
olcSpSessionLog: 100

root@dlp:~#

ldapadd -Y EXTERNAL -H ldapi:/// -f syncprov.ldif

SASL/EXTERNAL authentication started
SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth
SASL SSF: 0
adding new entry "olcOverlay=syncprov,olcDatabase={1}mdb,cn=config"

[3]	Configure LDAP Consumer.

root@node01:~#

vi syncrepl.ldif

# create new

dn: olcDatabase={1}mdb,cn=config
changetype: modify
add: olcSyncRepl
olcSyncRepl: rid=001
  # LDAP server's URI
  provider=ldap://10.0.0.30:389/
  bindmethod=simple
  # your domain suffix
  binddn="cn=admin,dc=srv,dc=world"
  # directory manager's password
  credentials=password
  searchbase="dc=srv,dc=world"
  # includes subtree
  scope=sub
  schemachecking=on
  type=refreshAndPersist
  # [retry interval] [retry times] [interval of re-retry] [re-retry times]
  retry="30 5 300 3"
  # replication interval
  interval=00:00:05:00

root@node01:~#

ldapadd -Y EXTERNAL -H ldapi:/// -f syncrepl.ldif

SASL/EXTERNAL authentication started
SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth
SASL SSF: 0
modifying entry "olcDatabase={1}mdb,cn=config"

# confirm settings to search data

root@node01:~#

ldapsearch -x -b 'ou=people,dc=srv,dc=world'

# extended LDIF
#
# LDAPv3
# base <ou=people,dc=srv,dc=world> with scope subtree
# filter: (objectclass=*)
# requesting: ALL
#

# people, srv.world
dn: ou=people,dc=srv,dc=world
objectClass: organizationalUnit
ou: people

# debian, people, srv.world
dn: uid=debian,ou=people,dc=srv,dc=world
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
sn: debian
givenName: debian
cn: debian
displayName: debian
uidNumber: 1000
gidNumber: 1000
gecos: debian
loginShell: /bin/bash
homeDirectory: /home/debian
shadowExpire: -1
shadowFlag: 0
shadowWarning: 7
shadowMin: 0
shadowMax: 99999
shadowLastChange: 19520
uid: debian
.....
.....

[4]	Configure LDAP Client to bind LDAP Consumer, too.

root@client:~#

vi /etc/nslcd.conf

# line 10 : add LDAP Consumer

uri ldap://dlp.srv.world/

ldap://node01.srv.world/

root@client:~#

systemctl restart nslcd

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