Integrate Identity with LDAP

Integrate Identity with LDAP

The OpenStack Identity service supports integration with existing LDAP directories for authentication and authorization services.

When the OpenStack Identity service is configured to use LDAP back ends, you can split authentication (using the identity feature) and authorization (using the assignment feature).

The identity feature enables administrators to manage users and groups by each domain or the OpenStack Identity service entirely.

The assignment feature enables administrators to manage project role authorization using the OpenStack Identity service SQL database, while providing user authentication through the LDAP directory.


For the OpenStack Identity service to access LDAP servers, you must enable the authlogin_nsswitch_use_ldap boolean value for SELinux on the server running the OpenStack Identity service. To enable and make the option persistent across reboots, set the following boolean value as the root user:

# setsebool -P authlogin_nsswitch_use_ldap on

The Identity configuration is split into two separate back ends; identity (back end for users and groups), and assignments (back end for domains, projects, roles, role assignments). To configure Identity, set options in the /etc/keystone/keystone.conf file. See Integrate Identity back end with LDAP for Identity back end configuration examples and Integrate assignment back end with LDAP for assignment back end configuration examples. Modify these examples as needed.


Multiple back ends are supported. You can integrate the OpenStack Identity service with a single LDAP server (configure both identity and assignments to LDAP, or set identity and assignments back end with SQL or LDAP), or multiple back ends using domain-specific configuration files.

To define the destination LDAP server

  1. Define the destination LDAP server in the keystone.conf file:

    url = ldap://localhost
    user = dc=Manager,dc=example,dc=org
    password = samplepassword
    suffix = dc=example,dc=org
    use_dumb_member = False
    allow_subtree_delete = False
  2. Configure dumb_member to true if your environment requires the use_dumb_member variable.

    dumb_member = cn=dumb,dc=nonexistent

Additional LDAP integration settings

Set these options in the /etc/keystone/keystone.conf file for a single LDAP server, or /etc/keystone/domains/keystone.DOMAIN_NAME.conf files for multiple back ends. Example configurations appear below each setting summary:

Query option

  • Use query_scope to control the scope level of data presented (search only the first level or search an entire sub-tree) through LDAP.
  • Use page_size to control the maximum results per page. A value of zero disables paging.
  • Use alias_dereferencing to control the LDAP dereferencing option for queries.
  • Use chase_referrals to override the system’s default referral chasing behavior for queries.
query_scope = sub
page_size = 0
alias_dereferencing = default
chase_referrals =


Use debug_level to set the LDAP debugging level for LDAP calls. A value of zero means that debugging is not enabled.

debug_level = 0


This value is a bitmask, consult your LDAP documentation for possible values.

Connection pooling

Use use_pool to enable LDAP connection pooling. Configure the connection pool size, maximum retry, reconnect trials, timeout (-1 indicates indefinite wait) and lifetime in seconds.

use_pool = true
pool_size = 10
pool_retry_max = 3
pool_retry_delay = 0.1
pool_connection_timeout = -1
pool_connection_lifetime = 600

Connection pooling for end user authentication

Use use_auth_pool to enable LDAP connection pooling for end user authentication. Configure the connection pool size and lifetime in seconds.

use_auth_pool = false
auth_pool_size = 100
auth_pool_connection_lifetime = 60

When you have finished the configuration, restart the OpenStack Identity service.


During the service restart, authentication and authorization are unavailable.

Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.