A new PortalContainerDefinition can be defined at the RootContainer level thanks to an external plugin, see below an example:

  <external-component-plugins>
    <!-- The full qualified name of the PortalContainerConfig -->
    <target-component>org.exoplatform.container.definition.PortalContainerConfig</target-component>
    <component-plugin>
      <!-- The name of the plugin -->
      <name>Add PortalContainer Definitions</name>
      <!-- The name of the method to call on the PortalContainerConfig in order to register the PortalContainerDefinitions -->
      <set-method>registerPlugin</set-method>
      <!-- The full qualified name of the PortalContainerDefinitionPlugin -->
      <type>org.exoplatform.container.definition.PortalContainerDefinitionPlugin</type>
      <init-params>
        <object-param>
          <name>portal</name>
          <object type="org.exoplatform.container.definition.PortalContainerDefinition">
            <!-- The name of the portal container -->
            <field name="name">
              <string>myPortal</string>
            </field>
            <!-- The name of the context name of the rest web application -->
            <field name="restContextName">
              <string>myRest</string>
            </field>
            <!-- The name of the realm -->
            <field name="realmName">
              <string>my-domain</string>
            </field>
            <!-- All the dependencies of the portal container ordered by loading priority -->
            <field name="dependencies">
              <collection type="java.util.ArrayList">
                <value>
                  <string>foo</string>
                </value>
                <value>
                  <string>foo2</string>
                </value>
                <value>
                  <string>foo3</string>
                </value>
              </collection>
            </field>
            <!-- A map of settings tied to the portal container -->
            <field name="settings">
              <map type="java.util.HashMap">
                <entry>
                  <key>
                    <string>foo</string>
                  </key>
                  <value>
                    <string>value</string>
                  </value>
                </entry>
                <entry>
                  <key>
                    <string>int</string>
                  </key>
                  <value>
                    <int>10</int>
                  </value>
                </entry>
                <entry>
                  <key>
                    <string>long</string>
                  </key>
                  <value>
                    <long>10</long>
                  </value>
                </entry>
                <entry>
                  <key>
                    <string>double</string>
                  </key>
                  <value>
                    <double>10</double>
                  </value>
                </entry>
                <entry>
                  <key>
                    <string>boolean</string>
                  </key>
                  <value>
                    <boolean>true</boolean>
                  </value>
                </entry>                                
              </map>
            </field>            
            <!-- The path to the external properties file -->
            <field name="externalSettingsPath">
              <string>classpath:/org/exoplatform/container/definition/settings.properties</string>
            </field>
          </object>
        </object-param>
      </init-params>
    </component-plugin>
  </external-component-plugins>

Internal and external settings are both optional, but if we give a non empty value for both the application will merge the settings. If the same setting name exists in both settings, we apply the following rules:

You can find below an example of how to use the variables:

<configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.exoplaform.org/xml/ns/kernel_1_1.xsd http://www.exoplaform.org/xml/ns/kernel_1_1.xsd"
  xmlns="http://www.exoplaform.org/xml/ns/kernel_1_1.xsd">
  <component>
    <type>org.exoplatform.container.TestPortalContainer$MyComponent</type>
    <init-params>
      <!-- The name of the portal container -->
      <value-param>
        <name>portal</name>
        <value>${portal.container.name}</value>
      </value-param>
      <!-- The name of the rest ServletContext -->
      <value-param>
        <name>rest</name>
        <value>${portal.container.rest}</value>
      </value-param>
      <!-- The name of the realm -->
      <value-param>
        <name>realm</name>
        <value>${portal.container.realm}</value>
      </value-param>
      <value-param>
        <name>foo</name>
        <value>${portal.container.foo}</value>
      </value-param>
      <value-param>
        <name>before foo after</name>
        <value>before ${portal.container.foo} after</value>
      </value-param>
    </init-params>
  </component>
</configuration>

In the properties file corresponding to the external settings, you can reuse variables previously defined (in the external settings or in the internal settings) to create a new variable. In this case the prefix "portal.container." is not needed, see an example below:

my-var1=value 1
my-var2=value 2
complex-value=${my-var1}-${my-var2}

In the external and internal settings, you can also use create variables based on value of System paramaters. The System parameters can either be defined at launch time or thanks to the PropertyConfigurator (see next section for more details). See an example below:

temp-dir=${java.io.tmpdir}${file.separator}my-temp

However, for the internal settings you can use System parameters only to define settings of type java.lang.String.

It cans be also very usefull to define a generic variable in the settings of the default portal container, the value of this variable will change according to the current portal container. See below an example:

my-generic-var=value of the portal container "${name}"

If this variable is defined at the default portal container level, the value of this variable for a portal container called "foo" will be value of the portal container "foo".