Hello World sample shows how to deploy SpringBoot RESTful web service application with Docker and with Kubernetes

Prerequisite

Installed:
Docker
git

Optional:
Docker-Compose
Java 1.8 or 11.1
Maven 3.x

Steps

Clone source code from git

git clone https://github.com/dstar55/docker-hello-world-spring-boot .

Build Docker image

docker build -t="hello-world-java" .

Maven build will be executes during creation of the docker image.

Note:if you run this command for first time it will take some time in order to download base image from DockerHub

Run Docker Container

docker run -p 8080:8080 -it --rm hello-world-java

Test application

curl localhost:8080

response should be:

Hello World

Stop Docker Container:

docker stop `docker container ls | grep "hello-world-java:*" | awk '{ print $1 }'`

Run with docker-compose

Build and start the container by running

docker-compose up -d 

Test application with curl command

curl localhost:8080

response should be:

Hello World

Stop Docker Container:

docker-compose down

Deploy under the Kuberenetes cluster

Prerequisite

MiniKube

Installed: MiniKube

Start minikube with command:

minikube start

Retrieve and deploy application

kubectl create deployment hello-spring-boot --image=dstar55/docker-hello-world-spring-boot:latest

Expose deployment as a Kubernetes Service

kubectl expose deployment hello-spring-boot --type=NodePort --port=8080

Check whether the service is running

kubectl get service hello-spring-boot

response should something like:

NAME                TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
hello-spring-boot   NodePort   xx.xx.xxx.xxx   <none>        8080:xxxxx/TCP   59m

Retrieve URL for application(hello-spring-boot)

minikube service hello-spring-boot --url

response will be http..., e.g:

http://127.0.0.1:44963

Test application with curl command(note: port is randomly created)

curl 127.0.0.1:44963

response should be:

Hello World