If you use Ansible to manage servers, you should probably use ssh keys to do so. Ssh keys are a way of authenticating to a server, like passwords are. Ssh keys can be protected with passwords or they can be passwordless. If you’re using them for automation, you might need to use passwordless ssh keys, but otherwise, it’s a good practice to protect the keys as well. You can create a key, or really a ssh key pair with the command

The first time you contact an ssh server, you’re presented with a fingerprint and asked whether you want to trust the server to be who it is, based on this fingerprint. Blindly, i might add. If you’re at least a bit concerned about (usable) security, this should send a few shivers down your spine; how the heck are you supposed to know whether this fingerprint is right or not. If you’re managing your servers with ansible, this query can be inconvenient, as it stops your flow at some random place and it’s not entirely clear where it will commence.