db-deployment.yaml

# Define a 'Persistent Voulume Claim'(PVC) for Mysql Storage, dynamically provisioned by cluster
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim # name of PVC essential for identifying the storage data
  labels:
    app: mysql
    tier: database
spec:
  accessModes:
    - ReadWriteOnce   #This specifies the mode of the claim that we are trying to create.
  resources:
    requests:
      storage: 1Gi    #This will tell kubernetes about the amount of space we are trying to claim.
---
# Configure 'Deployment' of mysql server
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql
  labels:
    app: mysq
    tier: database
spec:
  selector: # mysql Pod Should contain same labels
    matchLabels:
      app: mysql
      tier: database
  strategy:
    type: Recreate
  template:
    metadata:
      labels: # Must match 'Service' and 'Deployment' selectors
        app: mysql
        tier: database
    spec:
      containers:
        - image: ricardo2000/mysql:2.0 # image from docker-hub
          name: mysql
          env:
            - name: MYSQL_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mysql-secrets
                  key: password
          ports:
            - containerPort: 3306
              name: mysql
          volumeMounts:        # Mounting voulume obtained from Persistent Volume Claim
            - name: mysql-persistent-storage
              mountPath: /var/lib/mysql #This is the path in the container on which the mounting will take place.
            - name: mysql-initdb
              mountPath: /docker-entrypoint-initdb.d
      volumes:
        - name: mysql-persistent-storage # Obtaining 'vloume' from PVC
          persistentVolumeClaim:
            claimName: mysql-pv-claim
        - name: mysql-initdb
          configMap:
            name: mysql-initdb-config
---
# Define a 'Service' To Expose mysql to Other Services
apiVersion: v1
kind: Service
metadata:
  name: mysql  # DNS name
  labels:
    app: mysql
    tier: database
spec:
  ports:
    - port: 3306
      targetPort: 3306
  selector:       # mysql Pod Should contain same labels
    app: mysql
    tier: database
  clusterIP: None  # We Use DNS, Thus ClusterIP is not relevant