Automating Web Application Deployment via Git Pull and Service Restart

#!/bin/bash

# Configuration
APP_DIR="/var/www/my_webapp"
WEB_SERVER_SERVICE="nginx" # Or 'apache2'

# --- Deployment Steps ---

echo "Starting deployment for ${APP_DIR}..."

# 1. Navigate to the application directory
cd "${APP_DIR}" || {
  echo "Error: Cannot change directory to ${APP_DIR}. Aborting."
  exit 1
}

# 2. Pull the latest code from Git
echo "Pulling latest code from Git..."
git pull origin main || {
  echo "Error: Git pull failed. Aborting."
  exit 1
}

# 3. (Optional) Install/Update PHP Composer dependencies
if [ -f "composer.json" ]; then
  echo "Installing Composer dependencies..."
  composer install --no-dev --optimize-autoloader || {
    echo "Error: Composer install failed. Aborting."
    exit 1
  }
fi

# 4. (Optional) Install/Update Node.js dependencies (for frontend assets)
if [ -f "package.json" ]; then
  echo "Installing Node.js dependencies and building assets..."
  npm install --omit=dev && npm run build || {
    echo "Error: Node.js dependencies or build failed. Aborting."
    exit 1
  }
fi

# 5. (Optional) Run database migrations
if [ -f "artisan" ]; then # For Laravel applications
  echo "Running database migrations..."
  php artisan migrate --force || {
    echo "Error: Database migrations failed. Aborting."
    exit 1
  }
fi

# 6. Clear caches (example for Laravel)
if [ -f "artisan" ]; then
  echo "Clearing application caches..."
  php artisan optimize:clear
fi

# 7. Restart web server service
echo "Restarting ${WEB_SERVER_SERVICE} service..."
sudo systemctl restart "${WEB_SERVER_SERVICE}" || {
  echo "Error: Failed to restart ${WEB_SERVER_SERVICE}. Aborting."
  exit 1
}

echo "Deployment successful!"