ansible/examples/playbooks/upgraded_vars.yml

# in Ansible 1.2 and later, the $foo variable syntax, which is friendly enough for simple things
# has been upgraded to allow Jinja2 substitiutions as well, which is now the preferred Syntax.
# here is an example.  Note that Jinja2 conditionals belong only in templates.  Use ansible conditionals
# in playbooks.

---

  - hosts: all

    tasks:
      - shell: echo 'hello {{ ansible_hostname.upper() }}'

      - shell: echo 'match'
        when: 2 == 2

      - shell: echo 'no match'
        when: 2 == 2 + 1

      - shell: echo '{{ ansible_os_family }}'

      - shell: echo 'RedHat'
        when: ansible_os_family == 'RedHat'