The variable 'whoami' defined in the following places:
- role defaults -> whoami: mario
- extra vars (variables you pass to Ansible CLI with -e) -> whoami: toad
- host facts -> whoami: luigi
- inventory variables (doesn’t matter which type) -> whoami: browser
According to variable precedence, which one will be used?
Answer
The right answer is ‘toad’.
Variable precedence is about how variables override each other when they set in different locations. If you didn’t experience it so far I’m sure at some point you will, which makes it a useful topic to be aware of.
In the context of our question, the order will be extra vars (always override any other variable) -> host facts -> inventory variables -> role defaults (the weakest).
Here is the order of precedence from least to greatest (the last listed variables winning prioritization):
- command line values (eg “-u user”)
- role defaults [1]
- inventory file or script group vars [2]
- inventory group_vars/all [3]
- playbook group_vars/all [3]
- inventory group_vars/* [3]
- playbook group_vars/* [3]
- inventory file or script host vars [2]
- inventory host_vars/* [3]
- playbook host_vars/* [3]
- host facts / cached set_facts [4]
- play vars
- play vars_prompt
- play vars_files
- role vars (defined in role/vars/main.yml)
- block vars (only for tasks in block)
- task vars (only for the task)
- include_vars
- set_facts / registered vars
- role (and include_role) params
- include params
- extra vars (always win precedence)
A full list can be found at PlayBook Variables . Also, note there is a significant difference between Ansible 1.x and 2.x.