defaults/main.yml

@@ -1,7 +1,8 @@
 ---
-# @var redis_packages:description: Define a list of packages to install.
-redis_packages:
-  - redis5
+# @var redis_packages:description: >
+# Define a list of packages to install. The default packages depend on the OS version.
+# @end
+# @var redis_packages:default: $ "_unset_"
 
 # @var redis_packages_extra:description: Can be used to install other dependency packages.
 redis_packages_extra: []

molecule/rocky8/converge.yml

@@ -1,9 +1,5 @@
 ---
 - name: Converge
   hosts: all
-  vars:
-    redis_packages_extra:
-      - https://repo.ius.io/ius-release-el7.rpm
-      - https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
   roles:
     - role: xoxys.redis

tasks/main.yml

@@ -1,2 +1,15 @@
 ---
+- include_vars: "{{ var_files }}"
+  vars:
+    var_files: "{{ lookup('first_found', params, errors='ignore') }}"
+    params:
+      files:
+        - "{{ ansible_lsb.id | default('') | lower }}.yml"
+        - "{{ ansible_os_family | lower }}-{{ ansible_distribution_major_version }}.yml"
+        - "{{ ansible_os_family | lower }}.yml"
+      paths:
+        - "vars"
+  when: var_files
+
+- include_tasks: overwrites.yml
 - include_tasks: setup.yml

tasks/overwrites.yml

@@ -0,0 +1,5 @@
+---
+- name: Define redis_packages
+  set_fact:
+    redis_packages: "{{ __redis_packages | list }}"
+  when: redis_packages is not defined

vars/redhat-7.yml

@@ -0,0 +1,3 @@
+---
+__redis_packages:
+  - redis5

vars/redhat-8.yml

@@ -0,0 +1,3 @@
+---
+__redis_packages:
+  - "@redis:6"