OpenLDAP Replication2016/05/25

	Configure OpenLDAP Replication to continue Directory service if OpenLDAP master server would be down. OpenLDAP master server is called "Provider" and OpenLDAP Slave 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

# own domain name

  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 datas

root@node01:~#

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

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

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

root@www:~#

vi /etc/ldap.conf

# line 30: add LDAP Consumer

uri ldap://dlp.srv.world/

ldap://node01.srv.world/

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