Eclipse JKube - WebApp Example

Very simple Spring WebMVC framework application to demonstrate Eclipse JKube's capabilities regarding Java Web Applications.

How to Run

Requirements

The project is based in Java 11.

In order to run this example you will need a valid K8s cluster accessible via kubectl.

Compiling the project

$ mvn clean package

This will create a deployable war in ./target/example-0.0.0-SNAPSHOT.war

Building the image (Docker/S2I)

Using docker

$ mvn k8s:build

This will create a docker image tagged webapp/example:latest

Using S2I (requires OpenShift cluster)

$ mvn oc:build

This will create an ImageStream with name example (172.30.39.149:5000/jkube/example:latest)

Creating resource manifests

Kubernetes

$ mvn k8s:resource

This will generate resource manifests in target/classes/META-INF/jkube/kubernetes.yml

OpenShift

$ mvn oc:resource

This will generate resource manifests in target/classes/META-INF/jkube/openshift.yml

Deploying into the cluster

Kubernetes

NOTE: If you built your image using Docker, you'll either need to have a shared Docker Daemon with the cluster (e.g. eval $(minikube docker-env)) or push your image to an accessible registry first (i.e. mvn k8s:push).

$ mvn k8s:apply

A new Deployment will be created with name example

OpenShift

If you built your image using oc:build, your image will already be in the cluster, so there is no need to push it or have a shared Docker daemon.

$ mvn oc:apply

Testing the deployment

Your web application should now be deployed on the cluster, you can test the endpoint by:

# Minikube
$ curl $(minikube ip):$(kubectl get svc example -n default -o jsonpath='{.spec.ports[].nodePort}')
Hello!!!
# OpenShift
$ curl $(kubectl get routes.route.openshift.io example -o jsonpath='{.spec.host}')
Hello!!!