1. Connect to the EC2 Linux instance that you plan to add user accounts to.
2. Run the following command
sudo adduser <new_user>
3. Switch context to new user account
sudo su - <new_user>
4. Create .ssh directory
mkdir .ssh
5. Limit access to the .ssh directory
chmod 700 .ssh
6. Create the file ‘authorized_keys’ in the .ssh directory:
touch .ssh/authorized_keys
7. Change permission to authorized_keys
chmod 600 .ssh/authorized_keys
8. Run the following command to generate public key
ssh-keygen -y
enter location of .PEM key-pair
9. Copy output public to key to .ssh/authorized_keys
10. Verify that you can use SSH to connect to your instance.
ssh -i /path/<new_keypair>.pem <new_user>@public_dns_name_of_EC2_Linux_instance
