Generate deployment variables when joining a member server to a collective

We can use the genDeployVariables option of the collective join command to allocate deployment variables (ports) when we join a member server to a collective.

The genDeployVariables option registers deployment variables to the collective repository and generates deployment variables to the member file...

$WLP_USER_DIR/servers/server_name/configDropins/overrides/deployVariables.xml

Procedure

1. Create a collective controller.

2. Specify deployment variables in the collective controller server.xml file.

   Add a deployVariable element to the controller server.xml file for each port that we want allocated. A deployVariable typically specifies a name for the deployment variable, the initial port value, and the amount to increment the port value.

   <featureManager>
      <feature>servlet-3.0</feature>
      <feature>collectiveController-1.0</feature>   
   </featureManager>
   
   <deployVariable name="PortBase1" value="7000" increment="20"/> 
   <deployVariable name="PortBase2" value="8000" increment="20"/>
   

3. In server.xml of the server we want to join to the collective as a member, specify port values that use the deployment variables.

   The following defaultHttpEndpoint element shows example port values that use the deployment variables in server.xml of a server to be joined to the collective:

   <defaultHttpEndpoint id="httpEndpoint"
     host="*"
     httpPort="${PortBase1}"
     httpsPort="${PortBase1}+1"
     httpPort="${PortBase2}"
     httpsPort="${PortBase2}+1" />
   

4. Run the collective join command with the genDeployVariables option.

   wlp/bin/collective join memberName  \
       --host=controllerHost  \
       --port=controllerHTTPSPort \
       --user=controllerAdminUser  \
       --password=controllerAdminUserPassword \
       --keystorePassword=memberKeystorePassword  \
       --genDeployVariables

The command joins the server to the collective as a member, registers the deployment variables to the collective repository, and generates deployment variables to the member file...

$WLP_USER_DIR/servers/serverName/configDropins/overrides/deployVariables.xml

The generated file contains the following deployment variables for the example values:

<server>
   <variable name="PortBase1" value="7000"/>
   <variable name="PortBase2" value="8000"/>
</server>

Parent topic: Configure a Liberty collective