Setup of spring boot application & initialization of PostgreSQL database on Kubernetes – PART 2

• In the PART 1 of this blog series, we deployed a PostgreSQL database on minikube.
  
• In this part, we will deploy spring boot application .
  
• I have mentioned in PART 1 , how to dockerize and upload the order service to docker registry.
  
• The application.properties of the service , will get the details of database username, password and connection details from the environment variables mentioned in order service deployment yaml

spring.datasource.username=${SPRING_DATASOURCE_USERNAME}
spring.datasource.password=${SPRING_DATASOURCE_PASSWORD}
spring.datasource.url=${SPRING_DATASOURCE_URL}
]spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.PostgreSQLDialect
spring.jpa.hibernate.ddl-auto=update

• We will define a service object for us to access the application. yaml for service object
  

apiVersion: v1
kind: Service
metadata:
  name: order-svc-service
spec:
  ports:
    - protocol: "TCP"
      port: 8080
      targetPort: 8080
  selector:
    app: order-svc
  type: NodePort

• Service type is NodePort . It makes the service accessible on a static port on each Node in the cluster. This means that the service can handle requests that originate from outside the cluster.
  
• Next is deployment of order service and the yaml for that is

apiVersion: apps/v1
kind: Deployment
metadata:
  name: order-svc
spec:
  replicas: 1
  selector:
    matchLabels:
      app: order-svc
  template:
    metadata:
      labels:
        app: order-svc
    spec:
      containers:
       - image: raje/order-svc-k8
         name: order-svc
         ports:
           - containerPort: 8080
         env:
            - name: SPRING_DATASOURCE_PASSWORD
              value: changeme
            - name: SPRING_DATASOURCE_URL
              value: jdbc:postgresql://postgresql:5432/northwind?useSSL=false
            - name: SPRING_DATASOURCE_USERNAME
              value: postgres
            - name: SPRING_JPA_HIBERNATE_DDL_AUTO
              value: update

• Key elements of the deployment yaml
  • uses – raje/order-svc-k8 container image
  • Defines the enviornment variable
  • database is accessed with the name postgresql which is the name of the service for database
    
• Deploy the service and deployment objects by giving below command

kubectl apply -f order-svc-service.yaml
kubectl apply -f order-svc-deployment.yaml

• You can verify the deployment with the command – kubectl get all
  
• During the process if you want to check the logs of order service pod , you can give command kubectl logs <<podname>>
  
• To access and test the application , issue the below command

kubectl port-forward service/order-svc-service 7080:8080

• To access the API

curl http://localhost:7080/api/v1/customers

Source code for the application: https://github.com/rajeshsgr/order-svc-k8

Thank You . Please do share your comments and feedback !