Check master replication status.

[zangra-dev]

In tasks/replication.yml This errors occurs while I'm testing this role on vagrant guests.

Problem 1 has a delegate_to: "{{ mysql_replication_master }} option which in my case needed a remote_user to fix a remote SSH connection failure

Problem 2 a) When I give the remote_user: my ansible_user variable it gives me an "Unhandled exception occurred while templating" b) Using a custom group variable gives me an "msg": "'remote_user' is undefined"

solution is to set a variable in defaults/main.yml which can be overridden for the different used distribution ....

- name: Check master replication status.
  mysql_replication: mode=getprimary
  delegate_to: "{{ mysql_replication_master }}"
  remote_user: "{{ guest_user }}"
  register: master
  when:
    - (slave.Is_Replica is defined and not slave.Is_Replica) or (slave.Is_Replica is not defined and slave is failed)
    - mysql_replication_role == 'slave'
    - (mysql_replication_master | length) > 0
  tags: ['skip_ansible_galaxy']

- name: "debug 'master' var"
  debug:
    msg: "{{ master }}, guest_user: {{ guest_user }}"

This is also a follow up of #495