server installation

For new user
adduser user_name 

add sudo permission to the user
adduser user_name sudo

For generate key(local)
ssh-keygen -b 4096

copy key to server (ubuntu)
ssh-copy-id example_user@203.0.113.10

(MAC)
mkdir -p ~/.ssh && sudo chmod -R 700 ~/.ssh/ (server)
scp ~/.ssh/id_rsa.pub example_user@203.0.113.10:~/.ssh/authorized_keys (local)


Install RVM with RUBY AND RAILS
gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
\curl -sSL https://get.rvm.io | bash -s stable --rails
source ~/.rvm/scripts/rvm


Install NPM
sudo apt-get update
sudo apt-get install nodejs
sudo apt-get install npm


Disable root login
sudo vim /etc/ssh/sshd_config

set PermitRootLogin no
set PasswordAuthentication no

sudo systemctl restart sshd
or
sudo service ssh restart