I've followed the recommendations I could find to prevent this from happening. I am using Vagrant, but once the boxes are spun, I'd like to do things with the ansible command sometimes.
$ grep host_key /etc/ansible/ansible.cfg host_key_checking = False$ grep kafka01 ./inventorykafka01 ansible_host=127.0.0.1 ansible_port=2231 ansible_user='vagrant' ansible_ssh_private_key_file='/home/me/project/project/.vagrant/machines/kafka01/virtualbox/private_key' ansible_ssh_common_args='-o StrictHostKeyChecking=no'$ export ANSIBLE_HOST_KEY_CHECKING=False$ ansible kafka01 -m ping -i ./inventory [WARNING]: Unhandled error in Python interpreter discovery for host kafka01: Failed to connect to the host via ssh: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING:REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping onyou right now (man-in-the-middle attack)! It is also possible that a host key has just been changed. The fingerprint for the ECDSA key sent by the remote host isSHA256:jn5ClU5g566Gsvobf8Xc45DJnIiAllN+RJkg35Nf9KE. Please contact your system administrator. Add correct host key in /home/me/.ssh/known_hosts to get rid of this message. Offending ECDSA keyin /home/me/.ssh/known_hosts:19 remove with: ssh-keygen -f "/home/me/.ssh/known_hosts" -R "[127.0.0.1]:2231" ECDSA host key for [127.0.0.1]:2231 has changed and you have requested strictchecking. Host key verification failed.kafka01 | UNREACHABLE! => {.....What's going on here?
Edit: No, I don't want to keep deleting the key. I destroy/build these over and over again. I want to find the correct, long-term solution.