main.yml

---
#file: example.mysql/defaults/main.yml
mysql_options:
  #General
  user: mysql
  port: 3306
  default_storage_engine: InnoDB
  socket: /var/lib/mysql/mysql.sock
  pid_file: /var/run/mysqld/mysql.pid
  server_id: 1

my.cnf.j2

#file: example.mysql/templates/my.cnf.j2

[mysqld]

# General
port                           = {{ mysql_options['port'] }}
user                           = {{ mysql_options['user'] }}
default_storage_engine         = {{ mysql_options['default_storage_engine'] }}
socket                         = {{ mysql_options['socket'] }}
pid-file                       = {{ mysql_options['pid_file'] }}
server-id                      = {{ mysql_options['server_id'] }}

# Truncated

mysql-master-1.example.org

— #file: host_vars/mysql-master-1.example.org mysql_opts: server_id: 2

mysql_master.yml

---
#file: mysql_master.yml
- hosts: mysql_master

  roles:
    - role: example.mysql
      mysql_options: "{{mysql_opts}}"
      tags: ['mysql']