---
- name: check isc-dhcp-server
  service_facts:
  listen: 'restart isc-dhcp-server'

- name: restart dhcp server
  systemd:
    name: isc-dhcp-server
    state: restarted
  listen: 'restart isc-dhcp-server'
  when: not ansible_check_mode and ansible_facts.services['isc-dhcp-server']['state'] == 'running'