Bringing machine 'node1' up with 'virtualbox' provider...
Bringing machine 'node2' up with 'virtualbox' provider...
Bringing machine 'node3' up with 'virtualbox' provider...
==> node3: Running provisioner: setup (ansible_local)...
    node3: Running ansible-playbook...

PLAY [My little playbook] ******************************************************

TASK [create_user : Create group] **********************************************
fatal: [192.168.10.11]: FAILED! => {"failed": true, "msg": "ERROR! Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support this.  Please add this host's fingerprint to your known_hosts file to manage this host."}
fatal: [192.168.10.12]: FAILED! => {"failed": true, "msg": "ERROR! Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support this.  Please add this host's fingerprint to your known_hosts file to manage this host."}

PLAY RECAP *********************************************************************
192.168.10.11              : ok=0    changed=0    unreachable=0    failed=1
192.168.10.12              : ok=0    changed=0    unreachable=0    failed=1

Ansible failed to complete successfully. Any error output should be
visible above. Please fix these errors and try again.