postgres-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-deployment
spec:
  replicas: 1  # for the databases, we can't just increase the replicas of pods simpley, we need extra config, otherwise dasaster appears!!
  selector:
    matchLabels:
      component: postgres
  template:
    metadata:
      labels:
        component: postgres
    spec:
      volumes:
        - name: postgres-storage
          persistentVolumeClaim:
            claimName: database-persistent-volume
      containers:
        - name: postgres
          image: postgres
          ports:
            - containerPort: 5432
          volumeMounts:
            - name: postgres-storage  # the name here should be identical to the volumns name from line 16
              mountPath: /var/lib/postgresql/data  # here should be the default data saving path of the database in docker container
              subPath: postgres  # this is the folder name of the persistent volume, that mean what should be saved in mountPath will be saved in the persistent volume under the folder with subPath
          env:
            - name: POSTGRES_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: pgpassword
                  key: PGPASSWORD
---
apiVersion: v1
kind: Service
metadata:
  name: postgres-service
spec:
  type: ClusterIP
  selector:
    component: postgres
  ports:
    - port: 5432
      targetPort: 5432