Create User debian

setup-post-install-linux.sh

useradd -m -d /home/pivg -s /bin/bash pivg
passwd pivg
cp -r .ssh /home/pivg/

# ensure the directory ir owned by the new user
chown -R pivg:pivg /home/pivg/.ssh

# make sure only the new user has permissions
chmod 700 /home/pivg/.ssh
chmod 600 /home/pivg/.ssh/authorized_keys
usermod -aG sudo pivg

# https://humanwhocodes.com/snippets/2021/03/create-user-linux-ssh-key/

# Automatically upgrade apt packages
sudo apt update && sudo apt upgrade -y

# Install unattended upgrades
sudo apt install unattended-upgrades -y

# Enable auto updates for unattended upgrades
echo "unattended-upgrades unattended-upgrades/enable_auto_updates boolean true" | sudo debconf-set-selections

# Prevent SSH brute force attacks by installing fail2ban
sudo apt install fail2ban -y

# Install firewall ufw
sudo apt install ufw -y

# Rate limit SSH attempts
sudo ufw limit ssh/tcp

# Firewall rules
sudo ufw allow OpenSSH
sudo ufw allow dns
sudo ufw allow http
sudo ufw allow https

# Enable ufw and default to deny
sudo ufw enable
sudo ufw default deny incoming
sudo ufw default allow outgoing