Determine the Order of the Handlers#

Problem#

We have 2 tasks in which we potentially notify Handlers. How to determine or change the order of Handlers?

tasks/main.yml

- name: Configure Nginx service
  ansible.builtin.template:
    src: nginx.service.j2
    dest: /etc/systemd/system/nginx.service
    owner: root
    group: root
    mode: "0644"
  notify: Nginx restart

- name: Add managed vhost config files.
  ansible.builtin.template:
    src: "{{ item.template | default(nginx_vhost_template) }}"
    dest: "{{ nginx_vhost_path }}/{{ item.filename }}"
    owner: root
    group: www-data
    mode: 0644
  with_items: "{{ nginx_vhosts }}"
  notify: Nginx reload

Solution#

The order of execution of Handlers is based how they are ordered in your YAML configuration.

handlers/main.yml

# Executed first
- name: Nginx reload
  ansible.builtin.systemd:
    name: nginx
    state: reloaded

# Executed second
- name: Nginx restart
  ansible.builtin.systemd:
    name: nginx
    state: restart

Explanation#

Handler are not executed according to the order of notify, but, as with tasks, according to the declared order. In our solution, we have therefore deliberately set reload before restart.

Flush Handlers per Role

Orders of Handlers are defined per Play, so the order of your Roles in your Playbook and their Handlers define the order of execution of the Handlers. However, it often makes sense to have a Task at the end of each Role for flushing the Handlers related to coresponding Role.

- name: Flush handlers now
  ansible.builtin.meta: flush_handlers