wthiel / Ubuntu User Setup Script

#!/bin/bash # Ubuntu User Setup Script # Creates user account, sets up SSH keys from GitHub, and optionally grants sudo privileges # Must be run as root set -e # Exit on any error # Color codes for output RED='\033[0;31m' GREEN='\033[0;32m' YELLOW='\033[1;33m' BLUE='\033[0;34m' NC='\033[0m' # No Color # Function to print colored output print_status() { echo -e "${GREEN}[INFO]${NC} $1" } print_warning() { echo -e "${YELLOW}[WARNING]${NC} $1" } print_error() { echo -e "${RED}[ERROR]${NC} $1" } print_question() { echo -e "${BLUE}[QUESTION]${NC} $1" } # Check if running as root if [[ $EUID -ne 0 ]]; then print_error "This script must be run as root" exit 1 fi # Check if required tools are available if ! command -v curl &> /dev/null; then print_error "curl is required but not installed. Please install it first: apt update && apt install curl" exit 1 fi print_status "Starting Ubuntu User Setup Script" echo "==================================" echo # Step 1: Ask for username while true; do print_question "Enter the username for the new user account:" read -r USERNAME if [[ -z "$USERNAME" ]]; then print_warning "Username cannot be empty. Please try again." continue fi if [[ ! "$USERNAME" =~ ^[a-z_]([a-z0-9_-]{0,31}|[a-z0-9_-]{0,30}\$)$ ]]; then print_warning "Invalid username format. Please use lowercase letters, numbers, hyphens and underscores only." continue fi break done # Step 2: Create user account if it doesn't exist if id "$USERNAME" &>/dev/null; then print_warning "User '$USERNAME' already exists. Skipping user creation." else print_status "Creating user account '$USERNAME'..." useradd -m -s /bin/bash "$USERNAME" print_status "User '$USERNAME' created successfully with home directory." fi # Get user's home directory USER_HOME=$(eval echo "~$USERNAME") # Step 3: Ask for GitHub username while true; do print_question "Enter the GitHub username to fetch SSH keys from:" read -r GITHUB_USER if [[ -z "$GITHUB_USER" ]]; then print_warning "GitHub username cannot be empty. Please try again." continue fi # Validate GitHub user exists print_status "Validating GitHub user '$GITHUB_USER'..." HTTP_STATUS=$(curl -s -o /dev/null -w "%{http_code}" "https://api.github.com/users/$GITHUB_USER") if [[ "$HTTP_STATUS" == "200" ]]; then print_status "GitHub user '$GITHUB_USER' found." break elif [[ "$HTTP_STATUS" == "404" ]]; then print_warning "GitHub user '$GITHUB_USER' not found. Please check the username and try again." continue else print_warning "Unable to validate GitHub user (HTTP $HTTP_STATUS). Please check your internet connection and try again." continue fi done # Step 4: Download and setup SSH keys print_status "Downloading SSH keys for GitHub user '$GITHUB_USER'..." # Create .ssh directory with correct permissions SSH_DIR="$USER_HOME/.ssh" mkdir -p "$SSH_DIR" chmod 700 "$SSH_DIR" # Download SSH keys from GitHub KEYS_URL="https://github.com/$GITHUB_USER.keys" AUTHORIZED_KEYS_FILE="$SSH_DIR/authorized_keys" # Download keys and check if any were found KEYS_CONTENT=$(curl -s "$KEYS_URL") if [[ -z "$KEYS_CONTENT" ]] || [[ "$KEYS_CONTENT" == "Not Found" ]]; then print_warning "No public SSH keys found for GitHub user '$GITHUB_USER'." print_warning "The user will need to add SSH keys manually or use password authentication." # Create empty authorized_keys file touch "$AUTHORIZED_KEYS_FILE" else # Write keys to authorized_keys file (overwrites existing content) echo "$KEYS_CONTENT" > "$AUTHORIZED_KEYS_FILE" KEY_COUNT=$(echo "$KEYS_CONTENT" | wc -l) print_status "Successfully downloaded and installed $KEY_COUNT SSH key(s) for user '$USERNAME'." fi # Set correct permissions for SSH files chmod 600 "$AUTHORIZED_KEYS_FILE" chown -R "$USERNAME:$USERNAME" "$SSH_DIR" # Step 5: Ask about sudo privileges echo while true; do print_question "Should user '$USERNAME' get sudo privileges? (y/N):" read -r GRANT_SUDO case $GRANT_SUDO in [Yy]|[Yy][Ee][Ss]) # Add user to sudo group print_status "Adding user '$USERNAME' to sudo group..." usermod -aG sudo "$USERNAME" # Create sudoers file SUDOERS_FILE="/etc/sudoers.d/$USERNAME" print_status "Creating sudoers configuration file..." echo "$USERNAME ALL=(ALL:ALL) NOPASSWD: ALL" > "$SUDOERS_FILE" chmod 440 "$SUDOERS_FILE" # Validate sudoers file if visudo -c -f "$SUDOERS_FILE"; then print_status "User '$USERNAME' granted sudo privileges with NOPASSWD." else print_error "Error in sudoers file configuration. Removing file..." rm -f "$SUDOERS_FILE" exit 1 fi break ;; [Nn]|[Nn][Oo]|"") print_status "User '$USERNAME' will not have sudo privileges." break ;; *) print_warning "Please answer 'y' for yes or 'n' for no." ;; esac done # Step 6: Summary echo print_status "Setup completed successfully!" echo "==================================" echo "Summary:" echo "- User: $USERNAME" echo "- Home directory: $USER_HOME" echo "- SSH directory: $SSH_DIR (permissions: 700)" echo "- SSH keys source: GitHub user '$GITHUB_USER'" if [[ -n "$KEYS_CONTENT" ]] && [[ "$KEYS_CONTENT" != "Not Found" ]]; then echo "- SSH keys: $(echo "$KEYS_CONTENT" | wc -l) key(s) installed" else echo "- SSH keys: No keys found (manual setup required)" fi echo "- Sudo privileges: $(if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then echo "Yes (NOPASSWD)"; else echo "No"; fi)" echo print_status "The user '$USERNAME' can now connect via SSH using their GitHub SSH keys." if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then print_status "The user has passwordless sudo access." fi echo print_status "Setup script finished."