mohanpedala/sample-java-service

Sample Java Service

Build the service and run it

Build using maven
```
mvn clean install
```
Run the jar
- App will be launched on 8080 port you can change it as per your need.
```
java -jar sample-java-service-0.0.1-SNAPSHOT.jar --server.port=8080
```
Test the content using your favourite browser and call the below rest endpoint
```
http://localhost:8080/hello
```

Containerize the artifact and run it

Run the below command to build the image
```
docker build -t sample-java-app:v1 .
```
Run container

App will be launched on 8080 port you can change it as per your need.

docker run -d -p 8080:8080 --name sample-java-app sample-java-app:v1

Test the content using your favourite browser and call the below rest endpoint
```
http://localhost:8080/hello
```

Pre req for kuberntes:

Created this scenario on Macbook pro:
- Install Docker for mac: version Engine: 18.xx.x
- Enable Kubernetes: Click on Docker icon on the taskbar --> Preferences --> Kubernetes

Deploy app on Kubernetes

Deploy pods using deployment manifest.
```
kubectl create -f app-deployment.yml
```
Deploy service through a NodePort. Click here to know about NodePort
```
kubectl create -f app-svc.yml
```

Check the resorce using'

kubectl get all

Expected Output:

NAME                                         READY   STATUS    RESTARTS   AGE
pod/app-one-metadata-name-54465f9444-d58wc   1/1     Running   0          3m31s
pod/app-one-metadata-name-54465f9444-j8snn   1/1     Running   0          3m34s
pod/app-one-metadata-name-54465f9444-zbkrl   1/1     Running   0          3m36s

NAME                            TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)          AGE
service/app-one-metadata-name   NodePort    10.100.9.0   <none>        8080:30000/TCP   21m
service/kubernetes              ClusterIP   10.96.0.1    <none>        443/TCP          5d1h

NAME                                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/app-one-metadata-name   3/3     3            3           21m

NAME                                               DESIRED   CURRENT   READY   AGE
replicaset.apps/app-one-metadata-name-54465f9444   3         3         3       3m36s
replicaset.apps/app-one-metadata-name-674bdfd76    0         0         0       21m
replicaset.apps/app-one-metadata-name-7b48596fb7   0         0         0       5m6s

To see the console output of the service, open your browser and type the below url
```
http://localhost:30000/hello
```
Expected output with json viewer chrome plugin
```
// 20190914100042
// http://localhost:30000/hello

{
    "status": "hello"
}
```

Clean up Environment

Docker:

docker stop sample-java-app
docker rm $(docker ps -a -q)
docker rmi sample-java-app:v1

Kubernetes:

kubectl delete -f app-deployment.yml
kubectl delete -f app-svc.yml

K8s secret creation to access dockerhub.

First Create access token in Dockerhub. Click here for documentation.

On you cluster run the below command

kubectl create secret docker-registry --dry-run=true $secret_name \
--docker-server=<DOCKER_REGISTRY_SERVER> \
--docker-username=<DOCKER_USER> \
--docker-password=<DOCKER_PASSWORD> \
--docker-email=<DOCKER_EMAIL> -o yaml

Explanation:

<your-registry-server> is your Private Docker Registry FQDN. (https://index.docker.io/v1/ for DockerHub)
<your-name> is your Docker username.
<your-pword> is your Docker password.
<your-email> is your Docker email.

Add the below spec under the containers spec in the app-deployment.yml

---
spec:
  containers:
    - name: app-one-container
      image: phaneindra/sample-java-app:latest
      ports:
      - containerPort: 8080
      resources:
        requests:
          memory: "64Mi"
          cpu: "250m"
        limits:
          memory: "128Mi"
          cpu: "500m"
  
  imagePullSecrets:
  - name: docker-hub

---

mohanpedala / sample-java-service