Build and deploy a sample application to a Kubernetes container

About this task

Once you have set up a Kubernetes container runtime environment, build and deploy a small LoopBack application to confirm that it works properly.

Procedure

Get a simple LoopBack project.
If you don't have a simple "Hello World" LoopBack project handy, get the LoopBack "Getting Started" app. On one of the master nodes, enter the following commands:
```
git clone https://github.com/strongloop/loopback-getting-started
cd loopback-getting-started
```
Alternatively, you can create a new LoopBack project from scratch. For more information, see Tutorial: Creating a LoopBack® project from the command line.
Create a Dockerfile.
Create a file name Dockerfile in the Loopback application directory:
```
FROM node:slim
ADD . /app
WORKDIR /app
RUN npm install
CMD npm start
```
Build and publish the image.
Build the Docker image and tag it to publish to your Docker registry by entering this command:
```
docker build -t 127.0.0.1:30000/apps/testapp .
```
Once the image is built, publish it to the registry by entering this command:
```
docker push 127.0.0.1:30000/apps/testapp
```

Create a deployment manifest for the application named app.yml in your home directory:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: testapp-deployment
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: testapp
    spec:
      containers:
      - name: testapp
        image: 127.0.0.1:30000/apps/testapp
        ports:
        - containerPort: 3000
---
kind: Service
apiVersion: v1
metadata:
  name: testapp-service
spec:
  selector:
    app: testapp
  ports:
    - protocol: TCP
      port: 3000
      targetPort: 3000
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: testapp-ingress
  annotations:
    ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - http:
      paths:
      - path: /testapp
        backend:
          serviceName: testapp-service
          servicePort: 3000

Test the deployed application.
Once deployed, the application will be available at https://127.0.0.1/testapp. Enter the following command to retrieve data from the deployed app:
```
curl -k https://127.0.0.1/testapp/api/CoffeeShops
```