mariadb-deployment.yml

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mariadb-deployment
spec:
  selector:
    matchLabels:
      app: mariadb
  template:
    metadata:
      labels:
        app: mariadb
    spec:
      containers:
      - name: mariadb
        image: mariadb:10.4.4
        env:
        - name: MYSQL_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: mariadb-secrets
              key: mysql-root-password
        volumeMounts:
          - name: mariadb-pv
            mountPath: /var/lib/mysql
        ports:
        - containerPort: 3306
      volumes:
      - name: mariadb-pv
        persistentVolumeClaim:
          claimName: mariadb-pvc

mariadb-pvc.yml

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mariadb-pvc
  labels:
    app: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

mariadb-secrets.yml

apiVersion: v1
kind: Secret
metadata:
  name: mariadb-secrets
data:
  mysql-root-password: Mzk1MjgkdmRnN0pi

mariadb-service.yml

---
apiVersion: v1
kind: Service
metadata:
  name: mariadb
spec:
  type: ClusterIP
  ports:
  - port: 3306 # the port that this service will serve on
    targetPort: 3306 # should match containerPort
  selector:
    app: mariadb