How do I call a role from within another role in Ansible?

Question

My playbook runs a list of roles:

roles:
  - common
  - postgres
  - nginx
  - supervisord
  - { role: deploy_app,  app_name: myapp }
  - { role: deploy_app,  app_name: otherapp }

I have another role, celery, that I only want to run when the app named myapp is created using deploy_app. I was thinking I should pass a parameter into the role like this:

- { role: deploy_app,  app_name: myapp, celery: yes }

Then within my deploy_app role, I would use a when conditional:

- name: create celery worker for application
  <RUN ROLE HERE>
  when: '{{ celery }}' == 'yes'

How can I conditionally run a role from within a task list?

Answer 1

I think ansible depenencies would help here. Just create a /meta/main.yml inside your role with the following:

---
dependencies:
  - { role: celery, tags: ["sometag"], when: "celery == 'yes'" }