gistfile1.yml

---
- name: Group by Distribution
  hosts: all
  tasks:
    - group_by: key={{ansible_distribution}}

- name: Set Time Zone
  hosts: Ubuntu
  gather_facts: False
  vars:
  - my_zone: 'America/New_York'

  tasks:
    - name: check current timezone
      shell: cat /etc/timezone
      register: current_zone

    - name: Set timezone variables
      copy: content={{my_zone}}
            dest=/etc/timezone
            owner=root
            group=root
            mode=0644
            backup=yes
      when: current_zone.stdout != my_zone
      notify:
        - update timezone
  handlers:
    - name: update timezone
      command: dpkg-reconfigure --frontend noninteractive tzdata

Nice, thanks. You may want to add "changed_when: False" to the check task so it doesn't report back a changed status

You could also use the template function which already takes care of the idempotency for you. Also, you might consider to define a handler to restart syslog, some intrusion detection systems like fail2ban are relying on this.

Thanks for those two comments. I've found them useful for my setup.

"check current timezone" needs

changed_when: current_zone.stdout != "{{my_zone}}"

to stop nagging user about changed status!

When running ansible with --check it will cause this error:

fatal: [test] => error while evaluating conditional: current_zone.stdout != timezone

Any idea to solve this problem?

I found the solution: always_run: yes

Doesn't work. The ansible part works, but "dpkg-reconfigure --frontend noninteractive tzdata" will reset it to what it was before.

I added this task here

• name: ensure correct timezone link is set
  file:
  src: '/usr/share/zoneinfo/{{my_zone}}'
  dest: /etc/localtime
  owner: root
  group: root
  state: link

After that, the handler will do the right thing.

here is my solution

• name: Check current timezone
  shell: cat /etc/timezone
  register: current_timezone
  changed_when: false

• name: Set Timezone
  timezone:
  name: America/Chicago
  when: current_timezone.stdout != "America/Chicago"