Introduce variable for the tools to be installed

defaults/main.yml

@@ -143,3 +143,13 @@ mysql_use_percona_apt: false
 mysql_galera_resetup: false
 mysql_galera_members: []
 mysql_galera_primary_node: 'change_me' # See: https://github.com/ansible/ansible/issues/17453
+
+# -------------------------------------
+# Tools
+# -------------------------------------
+mysql_tools:
+  - mytop              # Not available on Debian Stretch (included in mariadb-client instead)
+  - percona-toolkit
+  - percona-xtrabackup # Not available on Debian Stretch (without using the Percona repository)
+  - python-mysqldb
+  - mysqltuner

tasks/install/main.yml

@@ -35,9 +35,4 @@
 
 - name: APT | Install few MySQL related tools
   apt: pkg={{ item }} state=present install_recommends=no
-  with_items:
-    - mytop
-    - percona-toolkit
-    - percona-xtrabackup
-    - python-mysqldb
-    - mysqltuner
+  with_items: "{{ mysql_tools }}"