Java and Kubernetes

Part one - base app:

Requirements:

Docker and k8s

Build and run application:

Spring boot and mysql database running on docker

Clone from repository

git clone https://github.com/anup1384/java-k8s.git

Build application

mvn clean install

Part two - app on Docker:

Create a Dockerfile:

FROM openjdk:11.0.3-jdk-slim
COPY target/*.jar /var/www/app.jar
EXPOSE 8080
ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -jar /var/www/app.jar" ]

Part three - app on Kubernetes:

We have an application and image running in docker Now, we deploy application in a kunernetes cluster running in our machine

Prepare

Start minikube

minikube start

Deploy database

kubectl apply -f k8s/mysql/ create mysql deployment and service

kubectl get pods

kubectl port-forward <pod_name> 3306:3306

Deploy application

kubectl apply -f k8s/app create app deployment and service

Check pods

kubectl get pods

Delete pod kubectl delete pod -n myapp-f7974h497-82k4r

Replicas kubectl get rs

Scale kubectl scale deployment/myapp --replicas=2

View replicas while true do curl "http://minikubeip/hello" echo sleep 2 done

Check app url

minikube service myapp --url

Change your IP and PORT as you need it

curl -X GET http://192.168.99.132:31838/persons

Add new Person curl -X POST http://192.168.99.100:31838/persons -H "Content-Type: application/json" -d '{"name": "New Person", "birthDate": "2000-10-01"}'