Ansible with_subelements default value

Question

i have a vars definition like this:

sites:
 - site: mysite1.com
   exec_init:
    - "command1 to exec"
    - "command2 to exec"
 - site: mysite2.com

then i have play with the following task

- name: Execute init scripts for all sites
  shell: "{{item.1}}"
  with_subelements: 
    - sites
    - exec_init
  when: item.0.exec_init is defined

The idea here is that i will have multiple "Site" definitions with dozens of other properties in my vars, then i would like to execute multiple Shell script commands for those sites having "exec_init" defined

Doing it this way it just always skip executing the task, i've tried this in all combinations i can imagine but i just can't get it to work...

Is this the proper way of doing it? maybe i'm trying to achieve something that doesn't make sense?

Thanks for your help

Answer 1

The valid solution here (considering ansible 2.7+) is to use loop instead of with_subelements. As with loop you can apply subelements filter, that has skip_missing option (ie what @hkariti suggested in option 3 but in proper way).

So, code should look like:

- name: Execute init scripts for all sites
  shell: "{{ item.1 }}"
  loop: "{{ sites | subelements('exec_init', skip_missing=True) }}"

Answer 2

This works for me. I am using version 2.1.1 Just add the third element in the subelements list as shown

- name: Iterate over something
  with_subelements:
     - "{{ unit }}"
     - config
     - skip_missing: True

Answer 3

There's another way, try:

- debug: "var=item"
  with_subelements:
    - "{{ sites | selectattr('exec_init', 'defined') | list }}"
    - exec_init

Thanks to: https://github.com/PublicaMundi/ansible-plugins/blob/master/lookup_plugins/subelements_if_exist.py