Conditionnal include and group_by in roles

[Julien Pepy]

Hi,

I'm struggling to solve a classical problem : building a multi-OS role without spawning unnecessary skipped statements. I've already read a lot of discussions on the subject (Dynamic 'include:' lines?, Conditional Include Question, Roles with multiple OS versions...), but I find no satisfying solution :

• task include with "when" statement does not really performs a conditional include, since it instantiates all tasks in the included file with an added "when" statement, so at runtime we get a lot of unnecessary skipped messages.
• task include file name is evaluated at parsing level, before any host is even contacted, so we can't use the same trick as with include_vars.
• the officially recommended solution, group_by, seems fine, but since we can't restrict a task to specific hosts, we can't use it in a role. It's designed to be used in a playbook, so it's not a real solution for a multi-OS role.

I think I've listed every alternative, but I may be missing something. If that's not the case, would it be possible to extend the task include statement to handle properly the when clause at runtime, depending on each host ?

Thanks for your help,

Julien

[dlun...@syberisle.com]

I ran into the same problem and my playbooks ended up looking like this, not pretty to say the least. Since I primarily manage FreeBSD machines. I had to move quite a few of my roles to handle the singular Ubuntu system that exists. 

my-play.yml

---
- hosts: all

  gather_facts: yes

  tasks:

    - group_by:

        key: "{{ ansible_os_family | lower }}"

- hosts: freebsd

  sudo: yes

  gather_facts: no

  vars:

    os_type: freebsd

  roles:

    - multi-os-role

- hosts: debian

  sudo: yes

  gather_facts: no

  vars:

    os_type: debian

  roles:

    - multi-os-role

roles/multi-os-role/tasks/main.yml

---

- include: "{{ os_type }}.yml"

# other tasks that are common between OS'

if you have steps that need to be run in different places in your task like I did, you can make the os_type a directory and do "{{ os_type }}/step-one.yml" or "{{ os_type }}/step-two.yml".