post_install() {
  getent group nova &>/dev/null || groupadd nova >/dev/null
  getent passwd nova &>/dev/null || useradd  -d /var/lib/nova -g nova -s /bin/false nova >/dev/null

  chmod 755 /etc/nova
  chown -R nova:nova /etc/nova
  chown root:root /etc/nova/rootwrap.conf
  chown -R root:root /etc/nova/rootwrap.d
  chown nova:nova /var/lib/nova
  chown nova /var/log/nova
  chown root:root /etc/sudoers.d/nova_sudoers
  chmod 440 /etc/sudoers.d/nova_sudoers
}

post_upgrade() {
  post_install
}

pre_remove() {
  getent passwd nova &>/dev/null && userdel nova >/dev/null
  getent group nova &>/dev/null && groupdel nova >/dev/null
  true
}