Si cuando intentamos conectar a un server nuevo con ANSIBLE, nos indica lo siguiente:

FAILED! => {"msg": "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."}

Esto es causado por la pregunta que salta en el server “Are you sure you want to continue connecting (yes/no)?”, para que no suceda, basta con acceder una vez por SSH al server y responder la pregunta, para que se incluya en la lista ECDSA permamente:

[redes@fe06-sha ansible]$ ssh xxxxx@xx.xx.xx.xx
The authenticity of host 'xx.xx.xx.xx (xx.xx.xx.xx)' can't be established.
ECDSA key fingerprint is SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
ECDSA key fingerprint is MD5:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'xx.xx.xx.xx' (ECDSA) to the list of known hosts.
xxxxx@xx.xx.xx.xx's password: