Ansible style guide: `INJECT_FACTS_AS_VARS = false`-compatible fact usage?

[andreashaerter]

To improve consistency and compatibility with INJECT_FACTS_AS_VARS = false, update the style guide to recommend using ansible_facts['<keyname>'] instead of the shorthand {{ ansible_<keyname> }} for fact references.

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Current Behavior:

The shorthand {{ ansible_<keyname> }} is commonly used to reference facts, which depends on the INJECT_FACTS_AS_VARS setting being enabled. However, for clarity, portability, and future-proofing playbooks, it is better to reference facts explicitly using ansible_facts['<keyname>'].

Example of the shorthand (current, not preferred):

- ansible.builtin.debug:  
    msg: "{{ ansible_distribution }}"  

Proposed Change:

Recommend the explicit usage of ansible_facts in the style guide for accessing facts. This ensures compatibility with INJECT_FACTS_AS_VARS = false, which disables the automatic injection of facts as top-level variables.

Example of the preferred method:

- ansible.builtin.debug:  
    msg: "{{ ansible_facts['distribution'] }}"  

Rationale:

• Compatibility: The shorthand relies on behavior tied to INJECT_FACTS_AS_VARS = true
• Explicit and readable: Using ansible_facts['<keyname>'] makes it clear where the data originates.