tl;dr Add a scope parameter to set_fact module, improving usability.
The current behavior of set_fact is to create a run-time only variable, in 2.x with private_role_vars this variable is scoped(*) to the role it is defined within.
It is helpful to be able to specify global facts in a few circumstances, such as passing information between roles or implementing once-per-playbook roles.
What I’d like to see is the set_fact module extended to support a scope parameter:
- playbook
- runtime lifetime.
- 1.x like behavior.
- 2.x behavior when
private_role_varsis not enabled. - role
- runtime lifetime.
- 2.x behavior when
private_role_varsis enabled. - corollary: should roles maintain state (set_fact’ed variables loaded back up) within the same playbook?
Additionally, the process for creating persistent facts in a role is a wee bit clunky (write out a json blob in facts.d, and force a potentially expensive fact reload).
So, a lifetime parameter:
- runtime
- default behavior
- persistent
- record fact to host’s facts.d, erroring if unable to do so.
- add fact to host’s in-memory ansible_local facts.
- optimization: does not trigger a fact reload.
(*) “Scoped” might be the wrong word here as the variable is deleted when the role ends. If the role is executed later in the playbook, the variable will not be defined.