OpenLDAP 2.4: Adding overlays

Mostly googlefood, since I spent way too long looking for this.

I wanted to load the unique plugin into my openLDAP 2.4 installation, and had a hell of a time, since so much of the documentation out there is for 2.2. Here’s what I did.

First, I told LDAP to load the plugin (forgetting this caused no end of grief):


root@ldap# cat /tmp/unique.1.ldif
dn: cn=module{0},cn=config
cn: module{0}
objectClass: olcModuleList
olcModulePath: /usr/lib64/openldap/
olcModuleLoad: unique.la
structuralObjectClass: olcModuleList

root@ldap# ldapadd -Y EXTERNAL -H ldapi:/// -f /tmp/unique.1.ldif

Then after that, loading in the configuration for the module itself.

root@ldap# cat /tmp/unique.2.ldif
dn: olcOverlay=unique,olcDatabase={2}bdb,cn=config
objectClass: olcOverlayConfig
objectClass: olcUniqueConfig
olcOverlay: unique
olcUniqueUri: ldap:///ou=people,dc=example,dc=com?uid?sub
olcUniqueUri: ldap:///ou=people,dc=example,dc=com?mail?sub
olcUniqueUri: ldap:///ou=people,dc=example,dc=com?uidNumber?sub
olcUniqueUri: ldap:///ou=groups,dc=example,dc=com?gidNumber?sub
olcUniqueUri: ldap:///ou=groups,dc=example,dc=com?cn?sub

root@ldap# ldapadd -Y EXTERNAL -H ldapi:/// -f /tmp/unique.2.ldif

4 Responses to “OpenLDAP 2.4: Adding overlays”

  1. Van Says:

    Darren, you are the man! I was looking for solution for uidNext + uidNumber junction. And finally, thanks to your post, I’ve done it. Thanks a lot!

  2. osee Says:

    I must agree with Van.
    This was indeed a lifesaver.

  3. cyril Says:

    Thx a lot man !

  4. Ron McLeod Says:

    I found with OpenLDAP 2.4.40, that I had to remove the structuralObjectClass attribute, otherwise it would fail:

    ldapadd -Y EXTERNAL -H ldapi:/// -f /tmp/unique.1.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{0},cn=config”
    ldap_add: Constraint violation (19)
    additional info: structuralObjectClass: no user modification allowed

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