k8s/manifests/02-deployments/deployment-postgres.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
  namespace: pg 
spec:
  selector:
   matchLabels:
    app: postgres
  replicas: 1
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
      - name: postgres
        image: postgres:latest
        imagePullPolicy: "IfNotPresent"
        env:
          - name: POSTGRES_USER
            valueFrom:
              secretKeyRef:
                name: postgres-secret
                key: postgres-root-username
          - name: POSTGRES_PASSWORD
            valueFrom:
              secretKeyRef:
                name: postgres-secret
                key: postgres-root-password
          - name: POSTGRES_DB
            valueFrom:
              configMapKeyRef:
                name: postgres-configmap
                key: postgres-dbname
        volumeMounts:
        - mountPath: /var/lib/postgresql/data
          name: postgredb 
          subPath: postgres 
      volumes:
        - name: postgredb
          persistentVolumeClaim:
            claimName: postgres-pv-claim
---
kind: PersistentVolume
apiVersion: v1
metadata:
  namespace: pg 
  name: postgres-pv-volume
  labels:
    type: local
    app: postgres
spec:
  storageClassName: longhorn
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteMany
  hostPath:
    path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  namespace: pg 
  name: postgres-pv-claim
  labels:
    app: postgres
spec:
  storageClassName: longhorn
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi