Sample MySQL deployment to initialize from *.sql file

mysql-init-demo.yaml

#  Here, I am using a gcePersistentDisk disk to store my init.sql file.
# You can you any Kubernetes volume such as hostPath,nfs etc.
apiVersion: apps/v1 
kind: Deployment
metadata:
  name: mysql-init-demo
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.6
        name: mysql
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: data
          mountPath: /var/lib/mysql
        - name: init-script
          mountPath: /docker-entrypoint-initdb.d # we are mounting init-script volume in this directory. so init.sql file will be available here.
      volumes:
      - name: data # this volume will be used for database storage.
        persistentVolumeClaim:
          claimName: mysql-data-pvc
      - name: init-script # this volume holds init.sql file.
        gcePersistentDisk:
          pdName: mysql-dump-storage
          fsType: ext4

Could you please help me out with this

I don't see any reason why you are getting this error. Perhaps more context will help to debug.