Adicionar outro usuário ao MySQL no Kubernetes

apiVersion: extensions/v1beta1
kind: Pod
metadata:
  name: mysql
spec:
  containers:
  - name: mysql
    image: mysql
    .....
    env:
    - name: MYSQL_ROOT_PASSWORD
      value: "root"
    .....
    volumeMounts:
      - name: mysql-initdb
        mountPath: /docker-entrypoint-initdb.d
  volumes:
  - name: mysql-initdb
    configMap:
      name: initdb

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: initdb
data:
  initdb.sql: |-
    CREATE USER 'first_user'@'%' IDENTIFIED BY '111' ;
    CREATE USER 'second_user'@'%' IDENTIFIED BY '222' ;

kubectl exec -it <PODNAME> -- mysql -uroot -p -e 'SELECT user, host FROM mysql.user;'

    +-------------+------+
    | user        | host |
    +-------------+------+
    | first_user  | %    |
    | second_user | %    |
    | root        | %    |
    +-------------+------+