Initial setup for new digital ocean droplet.

init.sh

#!/bin/bash

#inital setup for ubuntu 14.04 digital ocean droplet
#creates a new sudo user, copies root authorized keys file to user
#disables root and password logins

if [[ -z "$1" ]]; then
        echo "You didn't enter a username!"
        exit 1
fi

id -u "$1" > /dev/null || {
        adduser "$1"
        gpasswd -a "$1" sudo
}

ssh_dir="/home/${1}/.ssh"

if [[ ! -d "$ssh_dir" ]]; then
        mkdir "$ssh_dir"
fi

cp -r /root/.ssh/authorized_keys "${ssh_dir}/authorized_keys"
chown -R "$1:$1" "$ssh_dir"
chmod 600 "${ssh_dir}/authorized_keys"
sed -i 's/PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config
sed -i 's/#PasswordAuthentication yes/PasswordAuthentication no/' /etc/ssh/sshd_config
service ssh restart

#setup basic firewall rules
sudo ufw allow ssh
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw allow 25/tcp
sudo ufw enable

#create swap file
fallocate -l 2G /swapfile
chmod 600 /swapfile
mkswap /swapfile
swapon /swapfile
sh -c 'echo "/swapfile none swap sw 0 0" >> /etc/fstab'