How to add ssh keys to multiple hosts

Requisite

• list.txt: list of hosts
• ~/.ssh/id_rsa.pub: keys to add

Bash script

copy.sh

#!/bin/bash
for ip in `cat list.txt`; do
    sshpass -p "yourpassword" ssh-copy-id -o StrictHostKeyChecking=no -i ~/.ssh/id_rsa.pub medium@$ip
done

Explanation

• sshpass pass your password to the ssh prompt
• -o StrictHostKeyChecking=no ignores the “host identity not established” prompt, allowing sshpass to do its job

How to execute

sudo apt install -y sshpass
chmod +x copy.sh
./copy.sh

Reference

• 1: https://unix.stackexchange.com/questions/145182/copy-ssh-public-key-to-multiple-linux-hosts/489279
• 2: https://stackoverflow.com/questions/28461713/how-to-ignore-or-pass-yes-when-the-authenticity-of-host-cant-be-established-i