The repo cloud-native-starter contains an end-to-end sample application that demonstrates how to develop your first cloud-native applications. Two of the microservices have been developed with Java EE and MicroProfile. To simplify the creation of new Java EE microservices, I’ve added another very simple service that can be used as template for new services.
The template contains the following functionality:
- Image with OpenJ9, OpenJDK, Open Liberty and MicroProfile: Dockerfile
- Maven project: pom.xml
- Open Liberty server configuration: server.xml
- Health endpoint: HealthEndpoint.java
- Kubernetes yaml files: deployment.yaml and service.yaml
- Sample REST GET endpoint: AuthorsApplication.java, GetAuthor.java and Author.java
If you want to use this code for your own microservice, remove the three Java files for the REST GET endpoint and rename the service in the pom.xml file and the yaml files.
The microservice can be run in different environments:
- Docker
- Minikube
- IBM Cloud Kubernetes Service
In all cases get the code first:
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$ git clone https://github.com/nheidloff/cloud-native-starter.git
$ cd cloud-native-starter
$ ROOT_FOLDER=$(pwd)
Run in Docker
The microservice can be run in Docker Desktop.
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$ cd ${ROOT_FOLDER}/authors-java-jee
$ mvn package
$ docker build -t authors .
$ docker run -i --rm -p 3000:3000 authors
$ open http://localhost:3000/openapi/ui/
Run in Minikube
These are the instructions to run the microservice in Minikube.
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$ cd ${ROOT_FOLDER}/authors-java-jee
$ mvn package
$ eval $(minikube docker-env)
$ docker build -t authors:1 .
$ kubectl apply -f deployment/deployment.yaml
$ kubectl apply -f deployment/service.yaml
$ minikubeip=$(minikube ip)
$ nodeport=$(kubectl get svc authors --ignore-not-found --output 'jsonpath={.spec.ports[*].nodePort}')
$ open http://${minikubeip}:${nodeport}/openapi/ui/
Run in IBM Cloud Kubernetes Service
IBM provides the managed IBM Cloud Kubernetes Service. You can get a free IBM Cloud account. Check out the instructions for how to create a Kubernetes cluster.
Set your namespace and cluster name, for example:
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$ REGISTRY_NAMESPACE=niklas-heidloff-cns
$ CLUSTER_NAME=niklas-heidloff-free
Build the image:
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$ cd ${ROOT_FOLDER}/authors-java-jee
$ ibmcloud login -a cloud.ibm.com -r us-south -g default
$ ibmcloud ks cluster-config --cluster $CLUSTER_NAME
$ export ... // for example: export KUBECONFIG=/Users/$USER/.bluemix/plugins/container-service/clusters/niklas-heidloff-free/kube-config-hou02-niklas-heidloff-free.yml
$ mvn package
$ REGISTRY=$(ibmcloud cr info | awk '/Container Registry / {print $3}')
$ ibmcloud cr namespace-add $REGISTRY_NAMESPACE
$ ibmcloud cr build --tag $REGISTRY/$REGISTRY_NAMESPACE/authors:1 .
Deploy microservice:
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$ cd ${ROOT_FOLDER}/authors-java-jee/deployment
$ sed "s+<namespace>+$REGISTRY_NAMESPACE+g" deployment-template.yaml > deployment-template.yaml.1
$ sed "s+<ip:port>+$REGISTRY+g" deployment-template.yaml.1 > deployment-template.yaml.2
$ sed "s+<tag>+1+g" deployment-template.yaml.2 > deployment-iks.yaml
$ kubectl apply -f deployment-iks.yaml
$ kubectl apply -f service.yaml
$ clusterip=$(ibmcloud ks workers --cluster $CLUSTER_NAME | awk '/Ready/ {print $2;exit;}')
$ nodeport=$(kubectl get svc authors --output 'jsonpath={.spec.ports[*].nodePort}')
$ open http://${clusterip}:${nodeport}/openapi/ui/
$ curl -X GET "http://${clusterip}:${nodeport}/api/v1/getauthor?name=Niklas%20Heidloff" -H "accept: application/json"
Swagger UI
Once deployed the Swagger UI can be opened which shows the APIs of the authors service:
