Access to YAML file based nested variables in Ansible

Question

Imagine I have a YAML configuration file config.yml like the following:

---
vendor:
  url: https://acme.com

According to Ansible documentation, I can load this data structure into a variable:

- name: Include vars of stuff.yaml into the 'stuff' variable (2.2).
  ansible.builtin.include_vars:
    file: {{ lookup('ansible.builtin.env', 'STUFF') }}
    name: stuff

But how to use this variable and its subsidiaries? How to access the stuff/vendor/url variable properly, and is there a way to print out the whole variable tree?

Answer 1

To use those variables, you have to use the templating system of Ansible, which is Jinja.

Since your variable is currently an URL, here would be an example usage:

- ansible.builtin.get_url:
    url: "{{ stuff.vendor.url }}"
    dest: /tmp/vendor_page_copy

---

To see the content of the variable, you can:

1. use the debug module with the var parameter:

   - ansible.builtin.debug:
       var: stuff.vendor.url
   

   which outputs something like

   ok: [localhost] => 
     stuff.vendor.url: https://acme.com
   

   or

   - ansible.builtin.debug:
       var: stuff
   

   which outputs something like

   ok: [localhost] => 
     stuff:
       vendor:
         url: https://acme.com
   

2. use the debug module with the msg parameter, and template the variable:

   - ansible.builtin.debug:
       msg: "{{ stuff.vendor.url }}"
   

   which outputs something like

   ok: [localhost] => 
     msg: https://acme.com
   

   The same can be done with msg: "{{ stuff }}", as seen above.
3. run your playbook with the -v option:

   ansible-playbook play.yml -v
   

   which outputs something like

   ok: [localhost] => changed=false 
     ansible_facts:
       stuff:
         vendor:
           url: https://acme.com
     ansible_included_var_files:
     - /usr/local/ansible/stuff.yml
   

^{Note: your own output would seem really different that was is displayed here, and be in JSON, in a hard to read one liner. If this is the case, you would greatly benefit from using the YAML callback.}