Housing Benefit Calculation using Kogito

Showcases housing benefit calculation using Kogita BPMN and Rule Engine.

Idea taken from https://github.com/rikusarlin/DroolsHousingBenefit

Changes made to https://github.com/rikusarlin/DroolsHousingBenefit

BigDecimals replaced with doubles (makes DRL selectors easier, for example Foo(amount > 0))
No rule groups used
As much as possible done using DRL, so POJOs have no rule logic.

Swagger UI

Process description

Process is a very simple one. POJO BenefitApplication.java is gotten in via REST API. In the first process step "Apply Rules" rules from benefits.drl and Excel sheet are run. After that step localization using resource bundles is done and then there is a manual acceptance step in the process.

Note: you can edit the process diagram using VS Code extension called 'Kogito Bundle'

Running the application in dev mode

You can run your application in dev mode that enables live coding using:

mvn quarkus:dev

Testing application

See bin directory.

Packaging and running the application

The application can be packaged using mvn package. It produces the benefitapp-1.0-SNAPSHOT-runner.jar file in the /target directory. Be aware that it’s not an über-jar as the dependencies are copied into the target/lib directory.

The application is now runnable using java -jar target/benefitapp-1.0-SNAPSHOT-runner.jar.

Creating a native executable

You can create a native executable using: mvn package -Pnative.

Or, if you don't have GraalVM installed, you can run the native executable build in a container using: mvn package -Pnative -Dquarkus.native.container-build=true.

You can then execute your native executable with: ./target/benefitapp-1.0-SNAPSHOT-runner -Dquarkus.http.host=127.0.0.1

If you want to learn more about building native executables, please consult https://quarkus.io/guides/building-native-image.

Deployment to OpenShift

Create a new project

oc new-project benefitapplication

Create a build

oc new-build --name=benefit java:11 --binary=true

Start the build

oc start-build benefit --from-dir target --follow

After build has been finished, create an application using it:

oc new-app benefit -e JAVA_OPTIONS=-Dquarkus.http.host=0.0.0.0 -e JAVA_APP_JAR=benefitapp-1.0-SNAPSHOT-runner.jar

Expose the route

oc expose svc/benefit

Try it out

bin/ocp-send-1.sh

Known issues

Message bundles with native compilation

Example project demonstrating this https://github.com/tfriman/quarkus-native-resourcebundle This issue is possibly related to this oracle/graal#911

Debug print statements in DRL

These are not along the best practises but they make it easy to demonstrate quarkus:dev mode when you just change the debug function in DRL file.

tfriman/kogito-housing-benefit-application