Ansible loop over a list to define a dynamic dictionary - linux

Question

I am trying to define a dictionary FACTS_VAR in which the key must contain the word SUB. Argument_value and the value is true but when I loop over the variable Argument
hosts: all
gather_facts: true
vars:
Argument:
- value1
- value2
tasks:
- name: DEFINING A variable
set_fact:
FACTS_VAR: {'SUB..item': true}
loop: "{{Argument}}"
- debug:
var: FACTS_VAR
I got this result so I don't know what is missing there. I am expecting to get a dictionary like this
FACTS_ENTRY:
SUB.value1: true
SUB.value2: true
TASK [debug] *****************************************************************************************************************
ok: [control] => {
"FACTS_ENTRY": {
"SUB..item": true
}
}
ok: [ansible4] => {
"FACTS_ENTRY": {
"SUB..item": true
}

Answer 1

Create the keys
facts_entry_keys: "{{ ['sub']|product(argument)|map('join','.')|list }}"
gives
facts_entry_keys:
- sub.value1
- sub.value2
Create the dictionary
facts_entry: "{{ dict(facts_entry_keys|product([true])) }}"
gives
facts_entry:
sub.value1: true
sub.value2: true
Example of a complete playbook
- hosts: localhost
vars:
argument:
- value1
- value2
facts_entry_keys: "{{ ['sub']|product(argument)|map('join','.')|list }}"
facts_entry: "{{ dict(facts_entry_keys|product([true])) }}"
tasks:
- debug:
var: facts_entry

Answer 2

From your current description I understand only that you probably like to define variables somehow dynamically.
The following example could give some guidance.
---
- hosts: test
become: false
gather_facts: false
vars:
ARG:
- val1
- val2
tasks:
- name: Dynamically define variable
set_fact:
FACTS_VAR: "{ 'SUB_{{ item }}': true }"
loop: "{{ ARG }}"
- debug:
var: FACTS_VAR
resulting into an output of
TASK [Dynamically define variable] **
ok: [test.example.com] => (item=val1)
ok: [test.example.com] => (item=val2)
TASK [debug] ************************
ok: [test.example.com] =>
FACTS_VAR:
SUB_val2: true
Please take note that according your current description there can be only one value as result.
Further Q&A
Build variable name at play level