Calling roles in a loop using dictionaries from an array as vars - ansible

Question

My question is somehow similar to the one posted here, but that doesn't quite answer it.
In my case I have an array containing multiple vars: entries, which I loop over when calling a certain role. The following examples shows the idea:
some_vars_file.yml:
redis_config:
- vars:
redis_version: 6.0.6
redis_port: 6379
redis_bind: 127.0.0.1
redis_databases: 1
- vars:
redis_version: 6.0.6
redis_port: 6380
redis_bind: 127.0.0.1
redis_databases: 1
playbook.yml:
...
- name: Install and setup redis
include_role:
name: davidwittman.redis
with_dict: "{{ dictionary }}"
loop: "{{ redis_config }}"
loop_control:
loop_var: dictionary
...
As far as I understand, this should just set the dictionary beginning with the vars node on every iteration, but it somehow doesn't. Is there any chance to get something like this to work, or do I really have to redefine all properties at the role call, populating them using with_items?

Answer 1

Given the role
shell> cat roles/davidwittman_redis/tasks/main.yml
- debug:
var: dictionary
Remove with_dict. The playbook
shell> cat playbook.yml
- hosts: localhost
vars_files:
- some_vars_file.yml
tasks:
- name: Install and setup redis
include_role:
name: davidwittman_redis
loop: "{{ redis_config }}"
loop_control:
loop_var: dictionary
gives
shell> ansible-playbook playbook.yml
PLAY [localhost] **********************************************
TASK [Install and setup redis] ********************************
TASK [davidwittman_redis : debug] *****************************
ok: [localhost] =>
dictionary:
vars:
redis_bind: 127.0.0.1
redis_databases: 1
redis_port: 6379
redis_version: 6.0.6
TASK [davidwittman_redis : debug] ******************************
ok: [localhost] =>
dictionary:
vars:
redis_bind: 127.0.0.1
redis_databases: 1
redis_port: 6380
redis_version: 6.0.6
Q: "Might there be an issue related to the variable population on role call?"
A: Yes. It can. See Variable precedence. vars_files is precedence 14. Any higher precedence will override it. Decide how to structure the data and optionally use include_vars (precedence 18). For example
shell> cat playbook.yml
- hosts: localhost
tasks:
- include_vars: some_vars_file.yml
- name: Install and setup redis
include_role:
name: davidwittman_redis
loop: "{{ redis_config }}"
loop_control:
loop_var: dictionary
Ultimately, command line --extra-vars would override all previous settings
shell> ansible-playbook playbook.yml --extra-vars "#some_vars_file.yml"
Q: "Maybe it is not possible to set the vars section directly via an external dictionary?"
A: It is possible, of course. The example in this answer clearly proves it.