Step by step: create a pem file to login without password and without copy local keys to remote server. SSH authentication like AWS EC2.

login-without-password-and-without-copy-key-to-server.md

1. Login with account user (not root)

mkdir pem
cd pem
ssh-keygen -b 2048 -f identity -t rsa

2. Copy public key contents to authorized_keys

cat identity.pub >> ~/.ssh/authorized_keys

3. Disable Password Authentication

sudo nano /etc/ssh/sshd_config

Change to no to disable tunnelled clear text passwords

PasswordAuthentication no

4. Restart SSH

sudo service ssh restart

5. Download your private key to client side

cat ~/.ssh/pem/identity

6. Set permission for pem on your local

sudo chmod 600 identity.pem

7. Test login

ssh -i identity.pem user@vps-ip

Credits: https://medium.com/@nhancv/tech-setup-ssh-login-with-pem-file-without-password-on-ubuntu-linux-server-b97dda5a8b8c