Microservices (my-calc) uses the Kubernetes deployment and service, but it needs to communicate to other pods only. In other words, there's no need to expose it to the outside Kubernetes network. Therefore, the service type is set as ClusterIP:

$ cat my-calc.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-calc-deploy
spec:
  replicas: 2
  selector:
    matchLabels:
      run: my-calc
  template:
    metadata:
      labels:
        run: my-calc
    spec:
      containers:
      - name: my-calc
        image: hidetosaito/my-calc
---
apiVersion: v1
kind: Service
metadata:
  name: my-calc-service
spec:
  ports:
    - protocol: TCP
      port: 5000
  type: ClusterIP
  selector:
     run: my-calc

Use the kubectl command to load the my-calc pods as follows:

$ kubectl create -f my-calc.yaml 
deployment.apps "my-calc-deploy" created
service "my-calc-service" created