Policies describe administrative settings which can practically be used on more than one object. They facilitate the administration as they can be connected to containers and then apply to all the objects in the container in question and the objects in sub containers. The values are applied according to the inheritance principle. For every object, the applied value is always that which lies closest to the object in question.
If, for example, the same password expiry interval is to be defined for all users of a location, then a special container can be created for these users. After moving the user objects into the container, a password policy can be linked to the container. This policy is valid for all user objects within the container.
An exception to this rule is a value which was defined in a policy in the form of fixed attributes. Such values cannot be overwritten by subordinate policies.
The command line program univention-policy-result can be used to show in detail which policy applies to which directory service object.
Every policy applies to a certain type of UMC domain object, e.g., for users or DHCP subnets.
4.6.1. Creating a policy#
Policies can be managed via the UMC module Policies. The operation is the same as for the functions described in Univention Management Console modules.
The attributes and properties of the policies are described in the corresponding chapters, e.g. the DHCP policies in the network chapter.
The names of policies must not contain any umlauts.
Referencing objects provides a list of all containers or LDAP objects for which this policy currently applies.
The expanded settings host some general policy options which are generally only required in special cases.
- LDAP filter
A LDAP filter expression can be specified here, which an object must match for this policy to get applied.
- Required object classes
Here you can specify LDAP object classes that an object must possess for the policy to apply to this object. If, for example, a user policy is only relevant for Windows environments, the
sambaSamAccountobject class could be demanded here.
- Excluded object classes
Similar to the configuration of the required object classes, you can also list object classes here which should be excluded.
- Fixed attributes
Attributes can be selected here, the values of which may not be changed by subordinate policies.
- Empty attributes
Attributes can be selected here, which are to be set to empty in the policy, meaning they will be stored without containing a value. This can be useful for removing values inherited by an object from a superordinate policy. In subordinate policies, new values can be assigned to the attributes in question.
4.6.2. Applying policies#
Policies can be assigned in two ways:
A policy can be assigned to the LDAP base or a container/OU. To do so, the Policies tab in the properties of the LDAP object must be opened in the navigation (see LDAP directory browser).
A Policies tab is shown in the UMC modules of LDAP directory objects for which there are policies available (e.g., for users). A particular policy for a user can be specified at this place.
The Policies configuration dialogue is functionally identical; however, all policy types are offered when assigning policies to a LDAP container, whilst only the policy types applicable for the object type in question are offered when assigning policies to an LDAP object.
A policy can be assigned to the LDAP object or container under Policies. The values resulting from this policy are displayed directly. The Inherited setting means that the settings are adopted from a superordinate policy again - when one exists.
If an object is linked to a policy, or inherits policy settings which cannot be applied to the object, the settings remain without effect for the object. This makes it possible, for example, to assign a policy to the base entry of the LDAP directory, which is then valid for all the objects of the domain which can apply this policy. Objects which cannot apply to this policy are not affected.
4.6.3. Editing a policy#
Policies can be edited and deleted in the UMC module Policies. The interface is described in Univention Management Console modules.
When editing a policy, the settings for all the objects linked to this policy are changed! The values from the changed policy apply to objects already registered in the system and linked to the policy, in the same way as to objects added in the future.
The policy tab of the individual LDAP objects also includes the edit option, which can be used to edit the policy currently applicable for this object.