How to enable property substitution in deployment descriptors in EAP 6/7/8?

Solution Verified - Updated

Environment

  • Red Hat JBoss Enterprise Application Platform (EAP)
    • 8.x
    • 7.x
    • 6.x

Issue

  • How to enable property substitution (property replacement) in deployment descriptor in EAP 6 or 7?
  • Can property substitution be used in ejb-jar.xml, for example:
       <enterprise-beans>
          <message-driven>
             <ejb-name>...</ejb-name>
             <ejb-class>...</ejb-class>
             <activation-config>
                ...(snip)...
                <activation-config-property>                    
                   <activation-config-property-name>maxSession</activation-config-property-name>                    
                   <activation-config-property-value>${my.prop.config}</activation-config-property-value>
                </activation-config-property>
                ...(snip)...
             </activation-config>
          </message-driven>
       </enterprise-beans>

and then pass system properties at start-up via command line (e.g, -Dmy.prop.config=20) or via a properties file (e.g. -P myprops.properties) which contains name=value pairs.

  • In web.xml files, system-properties could be defined using ${} form (such as ${property}, set using -Dproperty=xyz and also could be set in the JBoss profile, but the value is not being expanded in the web.xml
 <system-properties>
        <property name="property" value="test"/>
 </system-properties>
  • Is it possible to change the context-root at deploy-time for a web-application in a given EAR file that includes an application.xml file, without changing the EAR file?
  • We are porting application from EAP 5.1.2 to EAP 6.2.0 in testing, observe org.apache.naming.resources.FileDirContext.setDocBase() does not support property substitution in EAP 6. Got the following error:
JBWEB000235: Allocate exception for servlet webdav: java.lang.IllegalArgumentException: JBWEB006706: Document base /opt/testapp/userAA/bin/${userAA.testapp.directory} does not exist or is not a readable directory
        at org.apache.naming.resources.FileDirContext.setDocBase(FileDirContext.java:147)
  • How to use dynamic values in the web.xml file ?
  • How to refer environment variables and/or system properties in web.xml
  • JAVA_OPTS defined variable foo=/somedir. Folder ${foo}/bar exists and got read-write permission for the application. In 6.4, the war file deployed fine. In EAP 7.2, war file deployed failed with error ${foo}/bar does not refer to a valid directory

Resolution

  • As mentioned in the configuration guides for EAP 7 and EAP 6, this behaviour can be enabled using property substitution configuration in the standalone.xml or domain.xml:
        <subsystem xmlns="urn:jboss:domain:ee:1.1">
            <spec-descriptor-property-replacement>true</spec-descriptor-property-replacement>
            <jboss-descriptor-property-replacement>true</jboss-descriptor-property-replacement>
        </subsystem>

  • spec-descriptor-property-replacement ("false" by default) is used to enable or disable property replacement in the following descriptors:

  • To enable the behavior via the Management CLI, run the following command:

/subsystem=ee:write-attribute(name="spec-descriptor-property-replacement",value=true)

  • jboss-descriptor-property-replacement ("true" by default) is used to enable or disable property replacement in the following descriptors:

    • jboss-ejb3.xml
    • jboss-app.xml
    • jboss-web.xml
    • *-jms.xml
    • *-ds.xml

  • To enable the behavior via the Management CLI, run the following command:

/subsystem=ee:write-attribute(name="jboss-descriptor-property-replacement",value=true)

Notes

Property substitution for permissions.xml and jboss-permissions.xml is in EAP 7.4+

Root Cause

  • The spec-descriptor-property-replacement or jboss-descriptor-property-replacement is set to false (depending on the deployment descriptor in which substitution is tried).

  • Certain versions of JBoss EAP 6.x do not have property substitution for the particular deployment descriptor (See bugs mentioned in resolution).

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