set_fact - Set host facts from a task


  • This module allows setting new variables. Variables are set on a host-by-host basis just like facts discovered by the setup module.
  • These variables will be available to subsequent plays during an ansible-playbook run, but will not be saved across executions even if you use a fact cache.
  • Per the standard Ansible variable precedence rules, many other types of variables have a higher priority, so this value may be overridden. See Variable Precedence Guide for more information.
  • This module is also supported for Windows targets.


Parameter Choices/Defaults Comments
(added in 2.4)
This boolean indicates if the facts set will also be added to the fact cache, if fact caching is enabled.
The set_fact module takes key=value pairs as variables to set in the playbook scope. Or alternatively, accepts complex arguments using the args: statement.



  • The var=value notation can only create strings or booleans. If you want to create lists/arrays or dictionary/hashes use var: [val1, val2]
  • This module is also supported for Windows targets.
  • Since ‘cacheable’ is now a module param, ‘cacheable’ is no longer a valid fact name as of 2.4.


# Example setting host facts using key=value pairs, note that this always creates strings or booleans
- set_fact: one_fact="something" other_fact="{{ local_var }}"

# Example setting host facts using complex arguments
- set_fact:
     one_fact: something
     other_fact: "{{ local_var * 2 }}"
     another_fact: "{{ some_registered_var.results | map(attribute='ansible_facts.some_fact') | list }}"

# Example setting facts so that they will be persisted in the fact cache
- set_fact:
    one_fact: something
    other_fact: "{{ local_var * 2 }}"
    cacheable: true

# As of 1.8, Ansible will convert boolean strings ('true', 'false', 'yes', 'no')
# to proper boolean values when using the key=value syntax, however it is still
# recommended that booleans be set using the complex argument style:
- set_fact:
    one_fact: true
    other_fact: false


This module is flagged as stableinterface which means that the maintainers for this module guarantee that no backward incompatible interface changes will be made.


For more information about Red Hat’s support of this module, please refer to this Knowledge Base article


  • Dag Wieers (@dagwieers)


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