Hello Server

You will need Docker and Java JDK installed to run this sdemo.

OpenJDK is available here: https://www.azul.com/downloads/zulu.
- Scroll down to Zulu CommunityTM Downloads
- Enter Java version, your platform and processor size.
Docker for Desktop is an easy option for Windows o MAcOS and has a one-click option to run Kubernetes as well.

Run as an Application

To build:

Windows:   mvnw package
Linux:     ./mvnw package

Should create an executable jar in target/. Run it:
```
java -jar target/hello-server-1.0.0.jar
```
Then either
- Open your browser to http://localhost:8080 - returns JSON, so best viewed using the JSON add-on for your browser
- Or, in a second CMD/Terminal window invoke curl http://localhost:8080
IMPORTANT: Stop the application once you are satisfied it is working to free up port 8080.

You might like to view the Dockerfile first to see what it configures.
Create a docker container (where docker-id is your Docker Hub id. If you don't have one, just use your first name):
```
docker build -t <docker-id>/hello-server .
```
Check it exists - it should be in this list:
```
docker images
```

To run:

docker run --name hello-server -p8080:8080 <docker-id>/hello-server

You should see Spring output to the console as it runs.

Again access http://localhost:8080 to check it's working

IMPORTANT: Hit CTRL-C to stop the container to free up port 8080.

To put your image up at Docker Hub, you need to run docker push <docker-id>/hello-server.
- However if you don't have a docker hub account or upoloading the image is too slow, you can use one I created earlier paulc4/hello-server.
Make sure kubectl is pointing at your Kubernetes cluster.
Create a dedicated namespace kubectl create namespace hello
Make it your default: kubectl config set-context <cluster-name> --namespace=hello
If you wish to use the image you just pushed, edit hello-server.yaml and change paulc4 to your docker-id, assuming you called the image <docker-id>/hello-server.
Deploy the web server: kubectl apply -f hello-server.yaml

What have we deployed:

kubectl get pods
kubectl get deployments

Go to Kubernetes dashboard, select hello namespace and view the pods.
Expose the web-service: kubectl expose deployment hello-server --type=LoadBalancer --port=8080 --target-port=8080
To see what IP-address was allocated to the application: kubectl get services -n paul. The output looks like:
```
$ kubectl get services
NAME                  CLUSTER-IP   EXTERNAL-IP         PORT(S)    AGE
hello-server          10.3.245.61  104.155.111.170     8080:32452/TCP   2m
```
The external IP may be a DNS name (for example if your cluster is on AWS).
Access http://<external-ip>:8080 to check it's working