Facts

A play gathers facts unless it sets gather_facts: false. Volant runs ansible-core’s own setup module for that, on the warm Python path.

- hosts: web
  tasks:
    - debug:
        msg: "{{ ansible_hostname }} runs {{ ansible_facts.distribution }}"

Because setup is a Python module, the controller needs ansible-core and the host needs a Python 3 interpreter. A controller without ansible-core stops a play that gathers facts before the first connection, instead of carrying on without them. Set gather_facts: false on plays that do not need facts.

Two names for each fact

Each fact is readable in two places:

• flat, with an ansible_ prefix: ansible_hostname
• inside ansible_facts, spelled the way the module returned it: ansible_facts.hostname

They are separate variables. A later set_fact of ansible_hostname shadows the flat one and leaves ansible_facts.hostname alone. Ansible behaves the same way.

Gathered facts rank above inventory variables and below the play’s own variables, see Precedence.

Facts are data

Facts are the host’s own words, so they arrive untrusted: a template inside a fact stays text and is never rendered. See Trusted and untrusted values.

Not there yet

• gather_subset and gather_timeout are not supported yet. Remove them and the play gathers the full set of facts.