Enable ssh passwordless login for large amount of servers

Install sshpass package

To install sshpass package on the source server from which to enable ssh passwordless login to remote servers:

-bash-4.2# rpm -ivh sshpass-1.06-1.el7.x86_64.rpm

Enable ssh passwordless login to remote servers

To enable ssh passwordless login to a large amount of remote servers, we can use the following command to automate without needs of providing password for each server.

-bash-4.2# for n in `seq 0 239`
do
    sshpass -p "password" ssh-copy-id -i /root/.ssh/id_rsa.pub -o StrictHostKeyChecking=no Client-hostname$n
done