Manage whole crontab files in Ansible - cron

Question

I have a crontab containing around 80 entries on a server. And I would like to manage that crontab using Ansible.
Ideally I would copy the server's crontab to my Ansible directory and create an Ansible task to ensure that crontab is set on the server.
But the cron module only seems to manage individual cron entries and not whole crontab files.
Manually migrating the crontab to Ansible tasks is tedious. And even if I find or make a tool that does it automatically, I feel the YAML file will be far less readable than the crontab file.
Any idea how I can handle that big crontab using Ansible?

Answer 1

I managed to find a simple way to do it. I copy the crontab file to the server and then update the crontab with the shell module if the file changed.
The crontab task:
---
- name: Ensure crontab file is up-to-date.
copy: src=tasks/crontab/files/{{ file }} dest={{ home }}/cronfile
register: result
- name: Ensure crontab file is active.
shell: crontab cronfile
when: result|changed
In my playbook:
- include: tasks/crontab/main.yml file=backend.cron

Answer 2

I solved this problem like this:
- name: Save out Crontabs
copy: src=../files/crontabs/{{ item }} dest=/var/spool/cron/{{ item }} owner={{item}} mode=0600
notify: restart cron
with_items:
- root
- ralph
- jim
- bob
The advantage of this method (versus writing to an intermediate file) is that any manual edits of the live crontab get removed and replaced with the Ansible controlled version. The disadvantage is that it's somewhat hacking the cron process.

Answer 3

Maintain idempotency by doing it this way:
- name: crontab
block:
- name: copy crontab file
copy:
src: /data/vendor/home/cronfile
dest: /home/mule/cronfile
mode: '0644'
register: result
- name: ensure crontab file is active
command: crontab /home/mule/cronfile
when: result.changed
rescue:
- name: delete crontab file
file:
state: absent
path: /home/mule/cronfile