Add python-pymysql to default packages and add mysql_connection variable

defaults/main.yml

@@ -2,6 +2,7 @@
 
 mysql_packages:
   - mariadb
+  - python-pymysql
 
 mysql_service_name: mariadb
 
@@ -13,5 +14,12 @@ mysql_main_conf:
   dest: /etc/my.cnf
 mysql_confd: []
 
+mysql_connection:
+  unix_socket: /run/mysqld/mysqld.sock
+  # host:
+  # port:
+  # user:
+  # password:
+
 mysql_databases: []
 mysql_users: []