Extending AD and Exchange Connector Schema HOWTO

Last modified 07 Sep 2022 03:49 +02:00

OBSOLETE

This functionality is obsolete. It is no longer supported or maintained.

Until recently, the schema in Active Directory and Microsoft Exchange connectors was defined statically at compile time. It has been present in ObjectClasses.xml resource files (both for AD and Exchange) that have been then compiled into connectors' DLLs. Because a couple of customers needed to support their own attributes by the connectors, we have provided a simple mechanism allowing to dynamically extend the schema.

In order to do this, we have introduced a new configuration parameter: *ObjectClassesExtensionFile. *It points to a file name, with a path relative to the place where AD/Exchange connector is installed. This file can contain wholly-new object classes or extensions to existing classes.

For example, you could create a schema.xml file with the following content:

<?xml version="1.0" encoding="utf-8" ?>
<List>

    <!-- Extending AccountObjectClass with two new attributes -->
    <ObjectClassInfo container="false" type="__ACCOUNT__">
        <AttributeInfos>
            <AttributeInfo name="__NAME__" type="String">
                <AttributeInfoFlag value="REQUIRED"/>
            </AttributeInfo>
            <AttributeInfo name="studentId" type="String"/>
            <AttributeInfo name="courses" type="String">
                <AttributeInfoFlag value="MULTIVALUED"/>
            </AttributeInfo>
        </AttributeInfos>
    </ObjectClassInfo>

    <!-- Defining a new object class -->
    <ObjectClassInfo container="false" type="Tenant">
        <AttributeInfos>
              <AttributeInfo name="__NAME__" type="String">
                <AttributeInfoFlag value="REQUIRED"/>
              </AttributeInfo>
              <AttributeInfo name="subtenants" type="String">
                <AttributeInfoFlag value="MULTIVALUED"/>
              </AttributeInfo>
              <AttributeInfo name="description" type="String"></AttributeInfo>
            <!-- ... -->
        </AttributeInfos>
    </ObjectClassInfo>

</List>

In the first part we extend the AccountObjectClass with two new attributes: studentId (String, single-valued) and courses (again String, but this time multi-valued). This is a common scenario to use when you have extended your Active Directory schema and want to make these extension attributes accessible via midPoint. (Due to connector framework restrictions, the __NAME__ attribute must be there, even if it is not being added.)

In the second part, we define a new object class. At first, you could wonder what could be the reason to do so? There is another recently-added feature to both AD and Exchange connector: custom scripting. It is now possible to define PowerShell scripts that are executed before, after or instead of any AD/Exchange connector operation. So, by defininng a new object class and a corresponding set of PowerShell scripts you can extend the connector functionality in unforeseen ways.

Back to our example. After creating the schema extension file, you would refer to it in your resource configuration:

<icfc:configurationProperties xmlns:ex="http://midpoint.evolveum.com/xml/ns/public/connector/icf-1/bundle/Exchange.Connector/Org.IdentityConnectors.Exchange.ExchangeConnector">
    <!-- ... -->
    <ex:ObjectClassesExtensionFile>schema.xml</ex:ObjectClassesExtensionFile>
</icfc:configurationProperties>

After that, you have to do the following:

restart Connector Server,
delete the schema from your resource definition - either deleting it manually using debug pages, or automating this process a little bit by using appropriately modified purge-resource-schema bulk action sample.

(These actions need to be done after each change of the schema, at least for now.)

Note: it is also possible to replace the original schema altogether, by using ObjectClassesReplacementFile configuration property. In that case, original ObjectClasses.xml is not used at all, and the replacement file is used instead.

All of the features described here are available in AD/Exchange connector version 1.4.1.20257 (experimental! download here: AD / Exchange). It requires latest connector framework, namely version 1.4.0.76.

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