Ansible with_subelements default value
Hm, looks like having a non-uniform structure for the elements in sites
is something with_subelements
doesn't like. And also that item
doesn't contain the subelement you specified in the with_subelements list. You can do several things:
Make sure to have an
exec_init
list, even if it's empty.with_subelements
will skip items with empty subelements. I think this is the best option, although a bit inconvenient when writing the playbook.Don't use
with_subelements
and batch execute yourself (a bit ugly):- name: Execute init scripts for all sites shell: "echo '{{item.exec_init | join(';')}}' | bash" when: item.exec_init is defined with_items: sites
Customize
with_subelements
so that it would items with the missing subelement. You can copy the original (mine is in/usr/local/lib/python2.7/dist-packages/ansible/runner/lookup_plugins/with_subelements.py
) and put it in alookup_plugins
directory next to your playbook, under a different name (saysubelements_missingok.py
). Then change line 59 from:raise errors.AnsibleError("could not find '%s' key in iterated item '%s'" % (subelement, item0))
to:
continue
Then your task can look like this:
- name: Execute init scripts for all sites debug: "msg={{item.1}}" with_subelements_missingok: - sites - exec_init
And yet another way, with the skip_missing flag (Ansible 2.0+):
- name: nested loop skip missing elements
with_subelements:
- sites
- exec_init
- flags:
skip_missing: true
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) }}"
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