In a regular task, we can use a conditional looped include to perform a set of tasks serially for each host:
- name: include when loop item is inventory_hostname
include_tasks: include.yml
when: inventory_hostname == item
loop: "{{ groups['x'] }}"
See include-loop.yml for a complete example. The included task in this case
displays the name of the host. If we run this multiple times we see that the
order of the includes is consistent between runs:
ansible-playbook -i inv include-loop.yml
Next, we can try this pattern from within a handler, as in
handler-include-loop.yml. Again, the order seems consistent.
ansible-playbook -i inv handler-include-loop.yml
In handler-include-loop2.yml, we use a command task to notify the handler,
rather than the debug task used previously. In this case, the order
becomes inconsistent. It seems that the task completion becoming
asynchronous causes the order of the handler host list to become ordered
differently from the main host list.
ansible-playbook -i inv handler-include-loop2.yml