You would use OpenLDAP with Nextcloud to centralize user management, allowing Nextcloud to authenticate users against an existing OpenLDAP directory, eliminating the need for separate Nextcloud accounts and enabling consistent control over user access and group memberships across multiple applications. This integration leverages OpenLDAP as the primary source of truth for user credentials, making it easier to manage users and permissions at scale. 

ldap Users and Groups

This example is using following users and groups in ldap:

• A technical user (ex: ro_admin), member of ldap_strict_readonly or ldap_password_manager
• A catch-all group called nextcloud_users.
• Members of nextcloud_users group will be authorized to log in Nextcloud.
• Some “application” groups, let’s say friends and family: users in Nextcloud will be able to share files and view people in dynamic lists only to members of their own group(s).
• Users in family and friends should also be users in nextcloud_users group!

If you plan on following this tutorial line-by-line, you will have the following: 

* 6 groups:  
1. nextcloud_users
2. family 
3. friends 
4. ldap_strict_readonly 
5. ldap_password_manager 
6. ldap_admin 

* 1 admin user in any of the following groups:  
1. ldap_password_manager  
2. ldap_strict_readonly 

* (At least) 1 user in the nextcloud_users group  
* (Optional) Any number of users in the friends or family group.

Nextcloud config: the cli way

Let’s script it. The “user_ldap” application is shipped with default Nextcloud installation (at least using Docker official stable images), you just have to install & enable it:

occ app:install user_ldap
occ app:enable user_ldap
occ ldap:create-empty-config

# EDIT: domain
occ ldap:set-config s01 ldapHost "ldap://ldap.example.net."
occ ldap:set-config s01 ldapPort 389
# EDIT: admin user
occ ldap:set-config s01 ldapAgentName "uid=ro_admin,ou=people,dc=example,dc=com"
# EDIT: password
occ ldap:set-config s01 ldapAgentPassword "password"
# EDIT: Base DN
occ ldap:set-config s01 ldapBase "dc=example,dc=com"
occ ldap:set-config s01 ldapBaseUsers "dc=example,dc=com"
occ ldap:set-config s01 ldapBaseGroups "dc=example,dc=com"
occ ldap:set-config s01 ldapConfigurationActive 1
occ ldap:set-config s01 ldapLoginFilter "(&(objectclass=person)(uid=%uid))"
# EDIT: nextcloud_users group, contains the users who can login to Nextcloud
occ ldap:set-config s01 ldapUserFilter "(&(objectclass=person)(memberOf=cn=nextcloud_users,ou=groups,dc=example,dc=com))"
occ ldap:set-config s01 ldapUserFilterMode 0
occ ldap:set-config s01 ldapUserFilterObjectclass person
occ ldap:set-config s01 turnOnPasswordChange 0
occ ldap:set-config s01 ldapCacheTTL 600
occ ldap:set-config s01 ldapExperiencedAdmin 0
occ ldap:set-config s01 ldapGidNumber gidNumber
# EDIT: list of application groups
occ ldap:set-config s01 ldapGroupFilter "(&(objectclass=groupOfUniqueNames)(|(cn=friends)(cn=family)))"
# EDIT: list of application groups
occ ldap:set-config s01 ldapGroupFilterGroups "friends;family"
occ ldap:set-config s01 ldapGroupFilterMode 0
occ ldap:set-config s01 ldapGroupDisplayName cn
occ ldap:set-config s01 ldapGroupFilterObjectclass groupOfUniqueNames
occ ldap:set-config s01 ldapGroupMemberAssocAttr uniqueMember
occ ldap:set-config s01 ldapEmailAttribute "mail" 
occ ldap:set-config s01 ldapLoginFilterEmail 0
occ ldap:set-config s01 ldapLoginFilterUsername 1
occ ldap:set-config s01 ldapMatchingRuleInChainState unknown
occ ldap:set-config s01 ldapNestedGroups 0
occ ldap:set-config s01 ldapPagingSize 500
occ ldap:set-config s01 ldapTLS 0
occ ldap:set-config s01 ldapUserAvatarRule default
occ ldap:set-config s01 ldapUserDisplayName displayname
occ ldap:set-config s01 ldapUserFilterMode 1
occ ldap:set-config s01 ldapUuidGroupAttribute auto
occ ldap:set-config s01 ldapUuidUserAttribute auto

With a bit of of luck, you should be able to log in your Nextcloud instance with OpenLDAP accounts in the nextcloud_users group.

Nextcloud config: the GUI way

1. enable LDAP application (installed but not enabled by default)
2. setup your ldap server in Settings > Administration > LDAP / AD integration
3. setup Group limitations

LDAP server config

Fill the OpenLDAP domain and port, DN + password of your technical account and base DN (as usual: change example.com by your own domain):

Users tab

Select person as object class and then choose Edit LDAP Query (the only from these groups option is not functional.) We want only users from the nextcloud_users group to be allowed to log in Nextcloud:

(&(objectclass=person)(memberOf=cn=nextcloud_users,ou=groups,dc=example,dc=com))

Login attributes

Select Edit LDAP Query and enter:

(&(objectclass=person)(uid=%uid))

Enter a valid username in ldap and check if your filter is working.

Groups

You can use the menus for this part: select groupOfUniqueNames in the first menu and check every group you want members to be allowed to view their group member / share files with.

Sharing restrictions

Go to Settings > Administration > Sharing and check following boxes:

• “Allow username autocompletion to users within the same groups”