Add default backend page for unmatched domains

- Add default backend template (hap_default_backend.tpl)
- Add customizable default page HTML template (default_page.html)
- Modify generate_config() to include default backend for unmatched domains
- Add environment variables for customizing default page content:
  - HAPROXY_DEFAULT_PAGE_TITLE
  - HAPROXY_DEFAULT_MAIN_MESSAGE
  - HAPROXY_DEFAULT_SECONDARY_MESSAGE
- Update README with documentation and examples
- Ensure backward compatibility with existing configurations
- Remove email contact link as requested

README.md

@@ -28,6 +28,7 @@ docker run -d -p 80:80 -p 443:443 -p 8000:8000 -v lets-encrypt:/etc/letsencrypt
 - **NEW**: Certificate download endpoints for other services
 - **NEW**: Comprehensive error logging and alerting system
 - **NEW**: Certificate status monitoring with expiration dates
+- **NEW**: Default backend page for unmatched domains
 
 ## Security
 
@@ -326,6 +327,34 @@ tail -f /var/log/haproxy-manager-errors.log
 | Variable | Description | Default |
 |----------|-------------|---------|
 | `HAPROXY_API_KEY` | API key for authentication (optional) | None (no auth) |
+| `HAPROXY_DEFAULT_PAGE_TITLE` | Title for the default page | Site Not Configured |
+| `HAPROXY_DEFAULT_MAIN_MESSAGE` | Main message on the default page | This domain has not been configured yet. Please contact your system administrator to set up this website. |
+| `HAPROXY_DEFAULT_SECONDARY_MESSAGE` | Secondary message on the default page | If you believe this is an error, please check the domain name and try again. |
+
+## Default Backend Configuration
+
+When a domain is accessed that hasn't been configured in HAProxy, the system will serve a default page instead of showing an error. This default page:
+
+- Informs visitors that the site is not configured
+- Displays the domain name and current timestamp
+- Is fully customizable through environment variables
+
+### Customizing the Default Page
+
+You can customize the default page by setting environment variables:
+
+```bash
+docker run -d \
+  -p 80:80 -p 443:443 -p 8000:8000 \
+  -v lets-encrypt:/etc/letsencrypt \
+  -v haproxy:/etc/haproxy \
+  -e HAPROXY_API_KEY=your-secure-api-key-here \
+  -e HAPROXY_DEFAULT_PAGE_TITLE="Website Coming Soon" \
+  -e HAPROXY_DEFAULT_MAIN_MESSAGE="This website is currently under construction and will be available soon." \
+  -e HAPROXY_DEFAULT_SECONDARY_MESSAGE="Please check back later or contact us for more information." \
+  --name haproxy-manager \
+  repo.anhonesthost.net/cloud-hosting-platform/haproxy-manager-base:latest
+```
 
 ## Example Usage
 

haproxy_manager.py

@@ -728,7 +728,12 @@ def generate_config():
         config_parts.append(letsencrypt_acl)
         config_acls = []
         config_backends = []
-# Add domain configurations
+        
+        # Add default backend rule (will be used when no domain matches)
+        default_rule = "    # Default backend for unmatched domains\n    default_backend default-backend\n"
+        config_parts.append(default_rule)
+        
+        # Add domain configurations
         for domain in domains:
             if not domain['backend_name']:
                 logger.warning(f"Skipping domain {domain['domain']} - no backend name")
@@ -782,6 +787,31 @@ def generate_config():
         # Add LetsEncrypt Backend
         letsencrypt_backend = template_env.get_template('hap_letsencrypt_backend.tpl').render()
         config_parts.append(letsencrypt_backend)
+        # Add Default Backend
+        try:
+            # Render the default page template with customizable content
+            default_page_template = template_env.get_template('default_page.html')
+            default_page_content = default_page_template.render(
+                page_title=os.environ.get('HAPROXY_DEFAULT_PAGE_TITLE', 'Site Not Configured'),
+                main_message=os.environ.get('HAPROXY_DEFAULT_MAIN_MESSAGE', 'This domain has not been configured yet. Please contact your system administrator to set up this website.'),
+                secondary_message=os.environ.get('HAPROXY_DEFAULT_SECONDARY_MESSAGE', 'If you believe this is an error, please check the domain name and try again.')
+            )
+            default_page_content = default_page_content.replace('"', '\\"').replace('\n', '\\n')
+            
+            default_backend = template_env.get_template('hap_default_backend.tpl').render(
+                default_page_content=default_page_content
+            )
+            config_parts.append(default_backend)
+        except Exception as e:
+            logger.error(f"Error generating default backend: {e}")
+            # Fallback to a simple default backend
+            fallback_backend = '''# Default backend for unmatched domains
+backend default-backend
+    mode http
+    option http-server-close
+    http-response set-header Content-Type text/html
+    http-response set-body "<!DOCTYPE html><html><head><title>Site Not Configured</title></head><body><h1>Site Not Configured</h1><p>This domain has not been configured yet.</p></body></html>"'''
+            config_parts.append(fallback_backend)
         # Add Backends
         config_parts.append('\n' .join(config_backends) + '\n')
         # Write complete configuration to tmp

templates/default_page.html

@@ -0,0 +1,91 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>{{ page_title }}</title>
+    <style>
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+            text-align: center;
+            padding: 50px 20px;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            margin: 0;
+            min-height: 100vh;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+        }
+        .container {
+            background: white;
+            padding: 40px;
+            border-radius: 12px;
+            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
+            max-width: 600px;
+            width: 100%;
+        }
+        .icon {
+            font-size: 64px;
+            margin-bottom: 20px;
+            display: block;
+        }
+        h1 {
+            color: #e74c3c;
+            margin-bottom: 20px;
+            font-size: 2.2em;
+            font-weight: 600;
+        }
+        p {
+            color: #555;
+            line-height: 1.7;
+            margin-bottom: 15px;
+            font-size: 1.1em;
+        }
+        .contact {
+            background: linear-gradient(135deg, #3498db, #2980b9);
+            color: white;
+            padding: 12px 24px;
+            border-radius: 6px;
+            text-decoration: none;
+            display: inline-block;
+            margin-top: 25px;
+            font-weight: 500;
+            transition: transform 0.2s ease, box-shadow 0.2s ease;
+        }
+        .contact:hover {
+            transform: translateY(-2px);
+            box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
+        }
+        .domain-info {
+            background: #f8f9fa;
+            border: 1px solid #e9ecef;
+            border-radius: 6px;
+            padding: 15px;
+            margin: 20px 0;
+            font-family: 'Courier New', monospace;
+            color: #495057;
+        }
+    </style>
+</head>
+<body>
+    <div class="container">
+        <span class="icon">⚠️</span>
+        <h1>{{ page_title }}</h1>
+        <p>{{ main_message }}</p>
+        <p>{{ secondary_message }}</p>
+        
+        <div class="domain-info">
+            <strong>Domain:</strong> <span id="domain"></span><br>
+            <strong>Time:</strong> <span id="timestamp"></span>
+        </div>
+        
+
+    </div>
+    
+    <script>
+        // Display the current domain and timestamp
+        document.getElementById('domain').textContent = window.location.hostname;
+        document.getElementById('timestamp').textContent = new Date().toLocaleString();
+    </script>
+</body>
+</html> 

templates/hap_default_backend.tpl

@@ -0,0 +1,12 @@
+# Default backend for unmatched domains
+backend default-backend
+    mode http
+    option http-server-close
+    http-request set-header X-Forwarded-Proto https if { ssl_fc }
+    http-request set-header X-Forwarded-Port %[dst_port]
+    http-request set-header X-Forwarded-For %[src]
+    http-request set-header X-Real-IP %[src]
+    
+    # Serve the default page HTML response
+    http-response set-header Content-Type text/html
+    http-response set-body "{{ default_page_content }}"