- name: "Change database root user password"
  mysql_user:
    name: root
    password: "{{ lookup('password','/dev/null chars=ascii_letters,digits length=32') }}"
    host: "{{ item }}"
    check_implicit_admin: yes
    priv: "*.*:ALL,GRANT"
    state: present
  when: mysql_root_result.stat.exists == False
  with_items:
  - localhost
  - "::1"
  - 127.0.0.1

[client]
user={{ item.user }}
password={{ item.password }}

# MariaDB: Set up secure root password
# Set up (and save) secure root password
# Check for /root/.my.cnf
# All the other things are skipped if this file already exists
- name: "Check if we already have a root password config"
  stat:
    path: /root/.my.cnf
  register: mysql_root_result

# Generate password
# This uses https://docs.ansible.com/ansible/latest/plugins/lookup/password.html
# to generate a 32 character random alphanumeric password
- name: "Generate database root password if needed"
  set_fact:
    mysql_root_passwd: "{{ lookup('password','/dev/null chars=ascii_letters,digits length=32') }}"
  when: mysql_root_result.stat.exists == False

# Generate /root/.my.cnf.new
# A temporary file is used to keep it from breaking further commands
# It also ensures that the password is on the server if the critical
# parts are interrupted
- name: "Save new root password in temporary file"
  template:
    src: my_passwd.cnf.j2
    dest: /root/.my.cnf.new
    owner: root
    group: root
    mode: 0400
  when: mysql_root_result.stat.exists == False
  with_items:
  - user: root
    password: "{{ mysql_root_passwd }}"

# START of area that you don't want to interrupt
# If this is interrupted after the first task
# it can be fixed by manually running this on the server
# mv /root/.my.cnf.new /root/.my.cnf
# If the playbook is reran before that. The password would be lost!
# Add DB user
- name: "Add database root user"
  mysql_user:
    name: root
    password: "{{ mysql_root_passwd }}"
    host: "{{ item }}"
    check_implicit_admin: yes
    priv: "*.*:ALL,GRANT"
    state: present
  when: mysql_root_result.stat.exists == False
  with_items:
  - localhost

# Now move the config in place
- name: "Rename config with root password to correct name - Step 1 - link"
  file:
    state: hard
    src: /root/.my.cnf.new
    dest: /root/.my.cnf
    force: yes
  when: mysql_root_result.stat.exists == False
# END of area that you don't want to interrupt

# Interrupting before this task will leave a temporary file around
# Everything will work as it should though
- name: "Rename config with root password to correct name - Step 2 - unlink"
  file:
    state: absent
    path: /root/.my.cnf.new
  when: mysql_root_result.stat.exists == False

# Remove additional root users - these don't have the password set
# You might want to ensure that none of these variables are `localhost`
# All return somewhat different values on my test system
- name: "Clean up additional root users"
  mysql_user:
    name: root
    host: "{{ item }}"
    check_implicit_admin: yes
    state: absent
  with_items:
  - "::1"
  - 127.0.0.1
  - "{{ ansible_fqdn }}"
  - "{{ inventory_hostname }}"
  - "{{ ansible_hostname }}"