I am trying to run a kubernetes closer locally using minikube. This is my first try with kubernetes. Therefore I am not familiar with all aspects of it. I am trying to deploy a spring boot app which connects to elastic search server.

springboot deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  labels:
    app: myapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myapp1:latest
          imagePullPolicy: Never

Elastic search sever deployment.yaml

    apiVersion: apps/v1
kind: Deployment
metadata:
  name: elasticsearch
spec:
  selector:
    matchLabels:
      run: elasticsearch
  replicas: 1
  template:
    metadata:
      labels:
        run: elasticsearch
    spec:
      containers:
        - image: docker.elastic.co/elasticsearch/elasticsearch:6.6.1
          name: elasticsearch
          imagePullPolicy: IfNotPresent
          env:
            - name: discovery.type
              value: single-node
            - name: cluster.name
              value: elasticsearch
          ports:
          - containerPort: 9300
            name: nodes
          - containerPort: 9200
            name: client

Exposed elastic search service as follows

apiVersion: v1
kind: Service
metadata:
  name: elasticsearch
  labels:
    service: elasticsearch
spec:
  ports:
    - name: client
      port: 9200
      protocol: TCP
      targetPort: 9200
    - name: nodes
      port: 9300
      protocol: TCP
      targetPort: 9300
  type: NodePort

  selector:
    run: elasticsearch

Similarly, I exposed service of springboot app also. Now I am wondering how can I connect from springboot services to elastic search service.

When springbbot and elastic search was normal deployment on the same machine ( not in kubernetes), I connected using as

RestClient.builder(new HttpHost("localhost", 9200))
                .build();

What's the best way to connect to the elastic search from springboot in kubernetes?

Save the ip of the elastic search service in an environment variable and use it in springboot or use the service name of the elastic search service?

Please advice