First of all I fixed by postgres deployment, there was some error of "pod has unbound PersistentVolumeClaims" , so i fixed that error by this post pod has unbound PersistentVolumeClaims

So now my postgres deployment is running.

kubectl logs spring-boot-postgres-sample-67f9cbc8c-qnkzg doesn't print anything, it means there is something wrong in config file. kubectl describe pod spring-boot-postgres-sample-67f9cbc8c-qnkzg stating that container is terminated and reason is completed, I fixed it by running container infinity time by adding

   # Just sleep forever
command: [ "sleep" ]
args: [ "infinity" ]

So now my deployment is running. But now i Exposed my service by

kubectl expose deployment spring-boot-postgres-sample --type=LoadBalancer --port=8080

but can't able to get External-Ip , so I did

kubectl patch svc <svc-name> -n <namespace> -p '{"spec": {"type": "LoadBalancer", "externalIPs":["172.31.71.218"]}}'

So I get my external-Ip as "172.31.71.218"

But now the problem is curl http://172.31.71.218:8080/ getting timeout

Anything i did wrong?

Here is my deployment.yml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: spring-boot-postgres-sample
  namespace: default
spec:
  replicas: 1
  template:
    metadata:
      name: spring-boot-postgres-sample
      labels:
        app: spring-boot-postgres-sample
    spec:
      containers:
      - name: spring-boot-postgres-sample
        command: [ "/bin/bash", "-ce", "tail -f /dev/null" ]
        env:
          - name: POSTGRES_USER
            valueFrom:
              configMapKeyRef:
                name: postgres-config
                key: postgres_user
          - name: POSTGRES_PASSWORD
            valueFrom:
              configMapKeyRef:
                name: postgres-config
                key: postgres_password
          - name: POSTGRES_HOST
            valueFrom:
              configMapKeyRef:
                name: hostname-config
                key: postgres_host
        image: <mydockerHUbaccount>/spring-boot-postgres-on-k8s:v1

Here is my postgres.yml

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-config
  namespace: default
data:
  postgres_user: postgresuser
  postgres_password: password
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: postgres
spec:
  template:
    metadata:
      labels:
        app: postgres
    spec:
      volumes:
        - name: postgres-storage
          persistentVolumeClaim:
            claimName: postgres-pv-claim
      containers:
        - image: postgres
          name: postgres
          env:
            - name: POSTGRES_USER
              valueFrom:
                configMapKeyRef:
                  name: postgres-config
                  key: postgres_user
            - name: POSTGRES_PASSWORD
              valueFrom:
                configMapKeyRef:
                  name: postgres-config
                  key: postgres_password
            - name: PGDATA
              value: /var/lib/postgresql/data/pgdata
          ports:
            - containerPort: 5432
              name: postgres
          volumeMounts:
            - name: postgres-storage
              mountPath: /var/lib/postgresql/data
---
apiVersion: v1
kind: Service
metadata:
  name: postgres
spec:
  type: ClusterIP
  ports:
    - port: 5432
  selector:
    app: postgres

Here How i got host-config map

kubectl create configmap hostname-config --from-literal=postgres_host=$(kubectl get svc postgres -o jsonpath="{.spec.clusterIP}")