Linux: SSH:Password for Few Users

https://serverfault.com/questions/285800/how-to-disable-ssh-login-with-password-for-some-users

https://serverfault.com/questions/307407/ssh-allow-password-for-one-user-rest-only-allow-public-keys

/etc/ssh/sshd_config
Match User <username>
PasswordAuthentication yes
Match all

/etc/ssh/sshd_config
Match User <username>
PasswordAuthentication yes
Match User all
PasswordAuthentication no




https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html
https://stackoverflow.com/questions/15543032/connecting-aws-ec2-instance-asks-for-password-although-pem-file-is-provided
https://aws.amazon.com/premiumsupport/knowledge-center/new-user-accounts-linux-instance/
https://linuxize.com/post/how-to-list-users-in-linux/
https://serverfault.com/questions/797482/how-to-make-ec2-user-data-script-run-again-on-startup
https://aws.amazon.com/premiumsupport/knowledge-center/execute-user-data-ec2/
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/connect-to-serial-console.html