K8S: PostgreSQL with Persistent Storage Volume

ConfigMap for PostgreSQL Configurations

Create file with configuration postgres-configmap.yaml:

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-config
  labels:
    app: postgres
data:
  POSTGRES_DB: postgresdb
  POSTGRES_USER: postgresadmin
  POSTGRES_PASSWORD: admin123

Creat ConfigMap:

kubectl create -f postgres-configmap.yaml
# configmap "postgres-config" created

Persistent Storage Volume

Create file with storage information postgres-storage.yaml:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: postgres-pv-volume
  labels:
    type: local
    app: postgres
spec:
  storageClassName: manual
  capacity:
    storage: 5Gi # Should be the same as in PersistentVolumeClaim
  accessModes:
    - ReadWriteMany
  hostPath:
    path: "/mnt/data"  #

---

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: postgres-pv-claim
  labels:
    app: postgres
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi # Should be the same as in PersistentVolume

Creat Storage Volume:

kubectl create -f postgres-storage.yaml
# persistentvolume "postgres-pv-volume" created
# persistentvolumeclaim "postgres-pv-claim" created

PostgreSQL Deployment

postgres-deployment.yaml Create file with deployment postgres-deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - name: postgres
          image: postgres:latest # Available https://hub.docker.com/_/postgres
          imagePullPolicy: "IfNotPresent"
          ports:
            - containerPort: 5432
          envFrom:
            - configMapRef:
                name: postgres-config # postgres-configmap.yaml
          volumeMounts:
            - mountPath: /var/lib/postgresql/data
              name: postgredb
      volumes:
        - name: postgredb
          persistentVolumeClaim:
            claimName: postgres-pv-claim # postgres-storage.yaml

Deploy:

kubectl create -f postgres-deployment.yaml
# deployment "postgres" created

Expose PostgreSQL

postgres-deployment.yaml Create service postgres-service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: postgres
  labels:
    app: postgres
spec:
  type: NodePort
  ports:
    - port: 5432
  selector:
    app: postgres

Create Service:

kubectl create -f postgres-service.yaml
# service "postgres" created

2022-09-02