After creation of machines, if want to create users and add sudoers

• useradd user_name
• passwd user_name
• after which open sudoers file add below line ( to open sudoers file vi /etc/sudoers )

user_name    ALL=(ALL:ALL) ALL

• once that's done, by default cloud machines password authentication is disabled. so we need to enable and restart ssh service using below commands

vi /etc/ssh/sshd_config change PasswordAuthentication no to as shown below

PasswordAuthentication yes

• systemctl restart sshd