Create ubuntu user and disable root login

README.md

RUN this first as root

curl -s https://gist.githubusercontent.com/shahidcodes/218a5c1331b87b45235a52a2b2382c46/raw/ea6b22452282aa5a1fd70c9fa7df393e89107e03/create-ubuntu-user.sh | sudo bash

Login using ubuntu user

Then run this as ubuntu user

curl -s https://gist.githubusercontent.com/shahidcodes/218a5c1331b87b45235a52a2b2382c46/raw/ea6b22452282aa5a1fd70c9fa7df393e89107e03/disable-root-pwd-login.sh | bash

create-ubuntu-user.sh

#!/bin/bash

# Check if script is running as root
if [ "$EUID" -ne 0 ]; then 
    echo "Please run as root"
    exit 1
fi

# Create ubuntu user if it doesn't exist
if ! id "ubuntu" &>/dev/null; then
    useradd -m -s /bin/bash ubuntu
    echo "Created user: ubuntu"
fi

# Set up sudo without password for ubuntu user
echo "ubuntu ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/ubuntu
chmod 440 /etc/sudoers.d/ubuntu

# Create .ssh directory for ubuntu user if it doesn't exist
UBUNTU_HOME="/home/ubuntu"
SSH_DIR="$UBUNTU_HOME/.ssh"
mkdir -p "$SSH_DIR"

# Copy root's authorized_keys to ubuntu user if it exists
ROOT_AUTH_KEYS="/root/.ssh/authorized_keys"
UBUNTU_AUTH_KEYS="$SSH_DIR/authorized_keys"

if [ -f "$ROOT_AUTH_KEYS" ]; then
    cp "$ROOT_AUTH_KEYS" "$UBUNTU_AUTH_KEYS"
    echo "Copied SSH authorized_keys from root to ubuntu user"
fi

# Set correct permissions
chown -R ubuntu:ubuntu "$SSH_DIR"
chmod 700 "$SSH_DIR"
chmod 600 "$UBUNTU_AUTH_KEYS"

echo "Setup completed successfully!"

disable-root-pwd-login.sh

#!/bin/bash

# Check if script is running as ubuntu user
if [ "$(whoami)" != "ubuntu" ]; then
    echo "This script must be run as ubuntu user"
    exit 1
fi

# Check if user has sudo privileges
if ! sudo -v &>/dev/null; then
    echo "Ubuntu user must have sudo privileges to run this script"
    exit 1
fi

# Backup sshd_config file
sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.backup.$(date +%Y%m%d_%H%M%S)

# Disable root login by modifying sshd_config
sudo sed -i 's/^PermitRootLogin.*$/PermitRootLogin no/' /etc/ssh/sshd_config

# If PermitRootLogin line doesn't exist, add it
if ! grep -q "^PermitRootLogin" /etc/ssh/sshd_config; then
    echo "PermitRootLogin no" | sudo tee -a /etc/ssh/sshd_config
fi

# Set additional secure SSH configurations
sudo sed -i 's/^PasswordAuthentication.*$/PasswordAuthentication no/' /etc/ssh/sshd_config
if ! grep -q "^PasswordAuthentication" /etc/ssh/sshd_config; then
    echo "PasswordAuthentication no" | sudo tee -a /etc/ssh/sshd_config
fi

# Verify the configuration file
echo "Verifying sshd_config..."
sudo sshd -t
if [ $? -eq 0 ]; then
    echo "SSH configuration is valid"
    # Restart SSH service
    sudo systemctl restart sshd
    echo "SSH service restarted"
    echo "Root login has been disabled successfully"
else
    echo "Error: SSH configuration is invalid"
    echo "Restoring backup..."
    sudo cp /etc/ssh/sshd_config.backup.$(ls -t /etc/ssh/sshd_config.backup.* | head -1) /etc/ssh/sshd_config
    exit 1
fi