This will update the remote ssh keys and reset the known_hosts file after a redeploy of new machines

update-keys.sh

#!/usr/bin/env bash
##
## This will update the remote ssh keys and reset the known_hosts file after a redeploy of a new VM
##


## will return the found *.example.com host names from an ansible file
## - alternatively, put your own logic here or give a fixed list:
## HOSTS=( host1.example.com host2.example.de )
HOSTS=( $(grep -o -e "[a-zA-Z0-9\-]*\.example\.com" inventory/heidelberg/inventory) )

if [[ -z ${SSHUSER} ]]; then
    echo -n ssh user:
    read SSHUSER
else
    echo "SSH User: ${SSHUSER}"
fi


if [[ -z ${SSHPASS} ]]; then
    echo -n ssh password:
    read -s SSHPASS
    echo
fi

export SSHPASS="${SSHPASS}"


if [[ -z ${SSHPASS} || -z ${SSHUSER} ]]; then
    echo "I require an ssh user (or \$SSHUSER) and ssh password (or \$SSHPASS)" >&2
    exit 1
fi

for host in "${HOSTS[@]}"; do
    echo "Updating ${host}"
    ssh-keygen -R "${host}" &> /dev/null || true
    ssh-keyscan "${host}" >> "${HOME}/.ssh/known_hosts" 2> /dev/null
    sshpass -e ssh-copy-id ${SSHUSER}@${host} > /dev/null
done