Chapter 4. Creating the HA CEP client

You must adapt your CEP client code to communicate with the HA CEP server image. Use the sample project included in the reference implementation for your client code. You can run your client code inside or outside the OpenShift environment.

Procedure

  1. Download the rhpam-7.8.0-reference-implementation.zip product deliverable file from the Software Downloads page of the Red Hat Customer Portal.
  2. Extract the contents of the file and then uncompress the rhpam-7.8.0-openshift-drools-hacep-distribution.zip file.
  3. Change to the openshift-drools-hacep-distribution/sources directory.
  4. Review and modify the client code based on the sample project in the sample-hacep-project/sample-hacep-project-client directory. Ensure that the code fulfills the additional requirements described in Chapter 5, Requirements for HA CEP client and server code.

  5. To update the KJAR version in an implementation that uses the method described in Chapter 3, Implementing the HA CEP server with a Maven repository for updating the KJAR service, add an UpdateKJarGAV call to the client, similar to the following code: 

            TopicsConfig envConfig = TopicsConfig.getDefaultTopicsConfig();
        Properties props = getProperties();
        try (RemoteStreamingKieSession producer = RemoteStreamingKieSession.create(props, envConfig)){
            producer.updateKJarGAV("org.kie:fake-jar:0.1");
        }

    Ensure that a KJAR with the specified GAV is available in the Maven repository when this call is executed.

  6. In the sample-hacep-project/sample-hacep-project-client directory, generate a keystore, using password as a password. Enter the following command: 

    keytool -genkeypair -keyalg RSA -keystore src/main/resources/keystore.jks

  7. Extract the HTTPS certificate from the OpenShift environment and add it to the keystore. Enter the following commands: 

    oc extract secret/my-cluster-cluster-ca-cert --keys=ca.crt --to=- > src/main/resources/ca.crt
keytool -import -trustcacerts -alias root -file src/main/resources/ca.crt -keystore src/main/resources/keystore.jks -storepass password -noprompt
  8. In the src/main/resources subdirectory of the project, open the configuration.properties file and replace <bootstrap-hostname> with the address that the route for the Kafka server provides.

  9. Build the project using the standard Maven command: 

    mvn clean install

  10. Change the sample-hacep-project-client project directory and enter the following command to run the client: 

    mvn exec:java -Dexec.mainClass="org.kie.hacep.sample.client.ClientProducerDemo"

    This command executes the main method of the ClientProducerDemo class.