localhost                                           remotehost
=========                                           ==========
                                                    // sudo root user
user:joe                                            user:admin
passsword:xxx                                       password:admin123
.ssh/id_rsa.pub ----------------------------------> ./ssh/authorised_keys

[defaults]
ansible_user=joe
ansible_ssh_user=admin
private_key_file=/home/pauloconnell/.ssh/id_rsa.pem

localhost                                           remotehost
=========                                           ==========
                                                    // sudo root user
user:joe                                            user:admin
passsword:xxx                                       password:admin123
~~.ssh/id_rsa.pub ----------------------------------> ./ssh/authorised_keys~~
user:ansible_ssh_user                               user:ansible_ssh_user
.ssh/id_rsa.pub ----------------------------------> ./ssh/authorised_keys

[defaults]
ansible_user=ansible_ssh_user
ansible_ssh_user=ansible_ssh_user
private_key_file=??