Move standard package lists to __mariadb_packages vars; clarify test guards

- Define __mariadb_packages (+ __mariadb_packages_mdbf for RedHat) in vars/ and
  set_fact them in variables.yml, matching the role's variable pattern; install
  tasks now use `mariadb_packages + mariadb_packages_extra` for clearer diffs
  and user-overridable base lists.
- Comment why rsync is used as the extra test package.
- Verify guard: use `mariadb_packages_extra | length > 0` (drop redundant
  default([]) since defaults/main.yml already provides []); comment why the
  explicit boolean is needed (ansible-core 2.19 rejects a non-boolean when:).

molecule/default/vars/testvars.yml

@@ -3,6 +3,8 @@ mariadb_server_id: 1
 mariadb_bind_address: 0.0.0.0
 mariadb_replication_role: primary
 
+# rsync is an arbitrary, lightweight package available in every target distro's
+# repos; it exercises the mariadb_packages_extra path without pulling in anything heavy.
 mariadb_packages_extra:
   - rsync
 

molecule/default/verify.yml

@@ -20,19 +20,22 @@
         that: not pkg_status.changed
         fail_msg: "{{ mariadb_server_package }} is not installed"
 
+    # `when: mariadb_packages_extra` relied on a list being implicitly truthy.
+    # ansible-core 2.19 rejects a non-boolean `when:` as an error, so the
+    # "list is non-empty" check must be explicit: `| length > 0`.
     - name: Verify extra packages status
       ansible.builtin.package:
         name: "{{ mariadb_packages_extra }}"
         state: present
       check_mode: true
       register: extra_pkg_status
-      when: mariadb_packages_extra | default([]) | length > 0
+      when: mariadb_packages_extra | length > 0
 
     - name: Check that extra packages are installed
       ansible.builtin.assert:
         that: not extra_pkg_status.changed
         fail_msg: "extra packages {{ mariadb_packages_extra }} are not installed"
-      when: mariadb_packages_extra | default([]) | length > 0
+      when: mariadb_packages_extra | length > 0
 
     - name: Register {{ mariadb_config_file }}
       ansible.builtin.stat:

tasks/setup_alpine.yml

@@ -1,7 +1,7 @@
 ---
 - name: Install packages (package)
   ansible.builtin.package:
-    name: "{{ [mariadb_server_package, 'mariadb-backup', 'mariadb-client', 'py3-pymysql'] + mariadb_packages_extra }}"
+    name: "{{ mariadb_packages + mariadb_packages_extra }}"
     state: present
   notify: Setup MariaDB
 

tasks/setup_debian.yml

@@ -77,6 +77,6 @@
 
 - name: Install packages (apt)
   ansible.builtin.apt:
-    package: "{{ [mariadb_server_package, 'mariadb-backup', 'python3-pymysql'] + mariadb_packages_extra }}"
+    package: "{{ mariadb_packages + mariadb_packages_extra }}"
     state: present
     update_cache: true

tasks/setup_redhat.yml

@@ -22,13 +22,13 @@
 
 - name: Install packages (dnf)
   ansible.builtin.dnf:
-    name: "{{ [mariadb_server_package, 'mariadb-backup', 'python3-PyMySQL'] + mariadb_packages_extra }}"
+    name: "{{ mariadb_packages + mariadb_packages_extra }}"
     state: present
   when: not mariadb_use_official_repo
 
 - name: Install packages (dnf/mdbf repo)
   ansible.builtin.dnf:
-    name: "{{ [mariadb_server_package_mdbf, 'MariaDB-backup', 'python3-PyMySQL'] + mariadb_packages_extra }}"
+    name: "{{ mariadb_packages_mdbf + mariadb_packages_extra }}"
     state: present
   when: mariadb_use_official_repo
 

tasks/variables.yml

@@ -28,6 +28,18 @@
     - ansible_facts.os_family == "RedHat"
     - mariadb_server_package_mdbf is not defined
 
+- name: Define mariadb_packages.
+  ansible.builtin.set_fact:
+    mariadb_packages: "{{ __mariadb_packages }}"
+  when: mariadb_packages is not defined
+
+- name: Define mariadb_packages_mdbf.
+  ansible.builtin.set_fact:
+    mariadb_packages_mdbf: "{{ __mariadb_packages_mdbf }}"
+  when:
+    - ansible_facts.os_family == "RedHat"
+    - mariadb_packages_mdbf is not defined
+
 - name: Define mariadb_config_file.
   ansible.builtin.set_fact:
     mariadb_config_file: "{{ __mariadb_config_file }}"

vars/Alpine.yml

@@ -8,3 +8,8 @@ __mariadb_unix_socket: "/run/mysqld/mysqld.sock"
 __mariadb_log_dir: "/var/log/mariadb"
 __mariadb_log_error_file: "{{ mariadb_log_dir }}/error.log"
 __mariadb_cron_package_name: "cronie"
+__mariadb_packages:
+  - "{{ mariadb_server_package }}"
+  - mariadb-backup
+  - mariadb-client
+  - py3-pymysql

vars/Debian.yml

@@ -8,3 +8,7 @@ __mariadb_unix_socket: "/run/mysqld/mysqld.sock"
 __mariadb_log_dir: "/var/log/mysql"
 __mariadb_log_error_file: "{{ mariadb_log_dir }}/error.log"
 __mariadb_cron_package_name: "cron"
+__mariadb_packages:
+  - "{{ mariadb_server_package }}"
+  - mariadb-backup
+  - python3-pymysql

vars/RedHat.yml

@@ -9,3 +9,11 @@ __mariadb_unix_socket: "/var/lib/mysql/mysql.sock"
 __mariadb_log_dir: "/var/log/mariadb"
 __mariadb_log_error_file: "{{ mariadb_log_dir }}/error.log"
 __mariadb_cron_package_name: "cronie"
+__mariadb_packages:
+  - "{{ mariadb_server_package }}"
+  - mariadb-backup
+  - python3-PyMySQL
+__mariadb_packages_mdbf:
+  - "{{ mariadb_server_package_mdbf }}"
+  - MariaDB-backup
+  - python3-PyMySQL