Chapter 17. Implementing the HA CEP server with a Maven repository for updating the KJAR service

Procedure

1. Download the rhpam-7.11.0-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-7.11.0-openshift-drools-hacep-distribution.zip file.
3. Change to the openshift-drools-hacep-distribution/sources directory.
4. Review and modify the server code based on the sample project in the sample-hacep-project/sample-hacep-project-kjar directory. The complex event processing logic is defined by the DRL rules in the src/main/resources/org/drools/cep subdirectory.

5. Build the project using the standard Maven command:

   mvn clean install -DskipTests

   Upload the resulting KJAR and any required dependencies to the Maven repository.

6. Enable the OpenShift operator for Red Hat AMQ Streams and then create an AMQ Streams (kafka) cluster in the project. For information about installing Red Hat AMQ Streams, see Using AMQ Streams on OpenShift.

7. To create the kafka topics that are required for operation of the server, remain in the openshift-drools-hacep-distribution/sources directory and run the following commands:

   oc apply -f kafka-topics/control.yaml
   oc apply -f kafka-topics/events.yaml
   oc apply -f kafka-topics/kiesessioninfos.yaml
   oc apply -f kafka-topics/snapshot.yaml

8. In order to enable application access to the ConfigMap that is used in the leader election, configure role-based access control. Change to the springboot directory and enter the following commands:

   oc create -f kubernetes/service-account.yaml
   oc create -f kubernetes/role.yaml
   oc create -f kubernetes/role-binding.yaml

   For more information about configuring role-based access control in Red Hat OpenShift Container Platform, see Using RBAC to define and apply permissions in the Red Hat OpenShift Container Platform product documentation.

9. In the springboot directory, edit the pom.xml file to remove the following dependency:

   <dependency>
         <groupId>org.kie</groupId>
         <artifactId>sample-hacep-project-kjar</artifactId>
   </dependency>

10. In the springboot directory, enter the following commands to create the image for deployment and push it into the repository configured for your OpenShift environment:

    oc new-build --binary --strategy=docker --name openshift-kie-springboot
    oc start-build openshift-kie-springboot --from-dir=. --follow

11. Enter the following command to detect the name of the image that was built:

    oc get is/openshift-kie-springboot -o template --template='{{range .status.tags}}{{range .items}}{{.dockerImageReference}}{{end}}{{end}}'

12. Open the kubernetes/deployment.yaml file in a text editor.
13. Replace the existing image URL with the result of the previous command.

14. Remove all characters at the end of the line starting with the @ symbol, then add :latest to the line. For example:

    image: image-registry.openshift-image-registry.svc:5000/hacep/openshift-kie-springboot:latest

15. Under the containers: line and the env: line, set environment variables as in the following example:

    containers:
      - env:
        - name: UPDATABLEKJAR
          value: "true"
        - name: KJARGAV
          value: <GroupID>:<ArtifactID>:<Version>
        - name: MAVEN_LOCAL_REPO
          value: /app/.m2/repository
        - name: MAVEN_MIRROR_URL
          value: http://<nexus_url>/repository/maven-releases/
        - name: MAVEN_SETTINGS_XML
          value: /app/.m2/settings.xml

    In this example, replace the value of the KJARGAV variable with the group, artifact, and version (GAV) of your KJAR service and the value of the MAVEN_MIRROR_URL variable with the URL to the Maven repository that contains your KJAR service.

    Optionally, set other variables. For a list of supported environment variables, see Section 17.1, “Optional environment variables supported by the HA CEP server”.

16. Save the file.

17. Enter the following command to deploy the image:

    oc apply -f kubernetes/deployment.yaml