How do I write an Ansible handler with multiple tasks?

Question

In response to a change, I have multiple related tasks that should run. How do I write an Ansible handler with multiple tasks?

For example, I would like a handler that restarts a service only if already started:

- name: Restart conditionally   shell: check_is_started.sh   register: result  - name: Restart conditionally step 2   service: name=service state=restarted   when: result 

Answer 1

There is proper solution to this problem as of Ansible 2.2.

handlers can also “listen” to generic topics, and tasks can notify those topics as follows:

handlers:     - name: restart memcached       service: name=memcached state=restarted       listen: "restart web services"     - name: restart apache       service: name=apache state=restarted       listen: "restart web services"  tasks:     - name: restart everything       command: echo "this task will restart the web services"       notify: "restart web services" 

This use makes it much easier to trigger multiple handlers. It also decouples handlers from their names, making it easier to share handlers among playbooks and roles

Specifically to the question, this should work:

- name: Check if restarted   shell: check_is_started.sh   register: result   listen: Restart processes  - name: Restart conditionally step 2   service: name=service state=restarted   when: result   listen: Restart processes 

and in the task, notify handlers via 'Restart processes'

http://docs.ansible.com/ansible/playbooks_intro.html#handlers-running-operations-on-change

Answer 2

In your handler file, chain the different steps together using notify.

- name: Restart conditionally   debug: msg=Step1   changed_when: True   notify: Restart conditionally step 2  - name: Restart conditionally step 2   debug: msg=Step2   changed_when: True   notify: Restart conditionally step 3  - name: Restart conditionally step 3   debug: msg=Step3 

Then refer to it from a task with notify: Restart conditionally.

Note that you can only notify to handlers below the current one. So for example, Restart conditionally step 2 can't notify Restart conditionally.

Source: #ansible at irc.freenode.net. I'm unsure whether this will continue to work in the future as it's not mentioned as a feature in the official documentation.