How to add NTP server to bosh VMs


Hi Expert,When deploy bosh from microbosh. How to make sure BOSH vms are configured with right NTP server?My manifest as below. But after deployment, ssh to bosh director,  /var/vcap/bosh/etc/ntpserver is not changed.

- name: health_monitor  template: health_monitor  instances: 1  resource_pool: small  networks:  - name: vlan249    static_ips:    -
properties:  env:  ntp: []
  blobstore:    address:    port: 25251    backend_port: 25552    agent:      user: agent      password: mysecretpw    director:      user: director      password: mysecretpw