mysql.yml

---
- name: Copy the MariaDB root non-interactive password
  template: src=mariadb_non_interactive_password.sh.j2 dest=/tmp/mariadb_non_interactive_password.sh owner=root group=root mode=0700

- name: Execute the MariaDN root non-interactive password file
  shell: /tmp/mariadb_non_interactive_password.sh

- name: Delete the non-interactive password file
  file: path=/tmp/mariadb_non_interactive_password.sh state=absent

- name: Add GPG key for MariaDB repo
  apt_key: id=0xcbcb082a1bb943db url=http://keyserver.ubuntu.com/pks/lookup?op=get&search=0xcbcb082a1bb943db

- name: Add MariaDB 10.1 repo
  apt_repository: repo="deb http://sgp1.mirrors.digitalocean.com/mariadb/repo/10.1/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} main" state=present
  register: add_mariadb_10_1_repo

- name: Install mariadb-server
  apt: name={{ item }} state=present update_cache=yes
  with_items:
    - mariadb-server
    - python-mysqldb # for ansible
  notify:
    - enable mariadb service
    - start mariadb service
  register: install_mariadb

- name: Create .my.conf file for root user
  template: src=.my.cnf.j2 dest=/root/.my.cnf owner=root mode=0600

- name: Update MariaDB root password for all root accounts
  mysql_user: name=root host={{ item }} password={{ mariadb_root_password }}
  with_items:
    - "{{ inventory_hostname }}"
    - 127.0.0.1
    - ::1
    - localhost
  tags: mariadb

# vim: set ts=2 sw=2:

Your .my.cnf.j2 is actually with a dot in the file system? Will you remember it's actually there if it's invisible?