README

This Symfony bundle provides an automated solution for managing dynamic IP addresses in Apache's access control configurations. In environments where IP addresses change regularly, maintaining accurate access control becomes challenging. This bundle solves that problem by automatically synchronizing your Apache configuration with the current IP addresses of your dynamic DNS domains.

Understanding Dynamic DNS and Access Control

Dynamic DNS (DDNS) is a method of automatically updating DNS records in real-time. It's commonly used when your IP address might change periodically, such as with residential internet connections or cloud services that don't provide static IPs. While DDNS ensures your domain always points to the correct IP, maintaining access control based on these IPs requires additional automation.

This bundle bridges that gap by monitoring your dynamic DNS domains and automatically updating your Apache configuration whenever IP changes are detected. It supports both IPv4 and IPv6, providing comprehensive coverage for modern network environments.

Core Features

The bundle has been designed with reliability and efficiency in mind:

Monitoring and Updates:

Tracks multiple dynamic DNS domains simultaneously
Supports both IPv4 and IPv6 address resolution
Implements intelligent caching to minimize unnecessary DNS queries
Provides automatic updates when IP changes are detected

Safety and Reliability:

Creates automatic backups before any modifications
Implements automatic rollback on failure
Provides comprehensive logging for all operations
Maintains atomic operations to prevent configuration corruption

Integration:

Seamlessly integrates with Symfony's ecosystem
Works with Apache's .htaccess configuration
Supports both manual and automated operation
Provides command-line interface for easy management

System Requirements

Before installation, ensure your environment meets these prerequisites:

PHP 8.1 or higher Required for modern language features and type safety
Symfony 6.0 or 7.0 Provides the foundation for robust application architecture
Apache web server with .htaccess support Necessary for implementing dynamic access control
Write permissions for the .htaccess file Required for automated configuration updates
DNS resolution capabilities Needed for resolving dynamic DNS entries

Installation and Setup

First, install the package using Composer:

composer require monosize/dynamic-dns-ip-updater

return [
    // ... other bundles ...
    Monosize\DynamicDnsIpUpdater\DynamicDnsIpUpdaterBundle::class => ['all' => true],
];

Configure your dynamic DNS domains by creating or updating your .env file:

# List your domains, separated by commas
# Example: DNS_DOMAINS=office.dynamicdns.net,backup.dyndns.org
DNS_DOMAINS=yourdomain1.example.org,yourdomain2.example.org

Configuration Management

The bundle manages a dedicated section in your .htaccess file, marked with clear delimiters:

# START DYNAMIC DNS BLOCK
# Dynamic DNS IPv4 addresses
Require ip 203.0.113.1
# Dynamic DNS IPv6 addresses
Require ip 2001:db8::1
# END DYNAMIC DNS BLOCK

This block is automatically maintained by the bundle. The clear delimiters ensure:

Easy identification of managed sections
Safe updates without affecting other configurations
Clean integration with existing access controls

Operation Modes

The bundle can operate in two primary modes:

Manual Operation

Use the command-line interface for direct control:

# Standard update - checks cache and updates only if needed
php bin/console dns:update-dynamic-ip

# Force update - bypasses cache and forces configuration refresh
php bin/console dns:update-dynamic-ip --force

Automated Operation

For continuous monitoring, you can implement automatic updates using either Symfony's Scheduler or traditional cron jobs.

Using Symfony Scheduler (Recommended):

# config/packages/scheduler.yaml
scheduler:
    dns_update:
        type: cron
        schedule: '*/5 * * * *'  # Updates every 5 minutes
        command: 'dns:update-dynamic-ip'

Using Traditional Crontab:

# Updates every 5 minutes
*/5 * * * * /usr/bin/php /path/to/your/project/bin/console dns:update-dynamic-ip

Understanding the Update Process

Each update cycle follows a carefully designed process to ensure reliability:

Domain Resolution:
- Reads configured domains from environment
- Resolves current IPv4 and IPv6 addresses
- Validates resolution results
Change Detection:
- Compares new IPs with cached values
- Determines if updates are necessary
- Optimizes performance by avoiding unnecessary writes
Safe Updates:
- Creates timestamped backup of current configuration
- Validates backup creation
- Implements update using atomic operations
Error Handling:
- Detects any problems during update
- Automatically restores from backup if needed
- Logs detailed error information
Cache Management:
- Updates cache with new IP addresses
- Sets appropriate cache expiration
- Maintains cache consistency

Monitoring and Logging

The bundle integrates with Symfony's logging system to provide comprehensive operational insights:

Configuration Changes:

IP address updates
Backup operations
Configuration modifications

Error Conditions:

DNS resolution failures
File operation issues
Permission problems

Performance Metrics:

Cache hits and misses
Update timing
Resource usage

Logs are written to your Symfony application's log directory (var/log/), following the standard Symfony logging conventions.

Development and Testing

The bundle includes a comprehensive test suite and development tools:

Running Tests:

# Complete test suite with all checks
composer check-all

# Individual components
composer test           # Unit tests
composer test-coverage  # Coverage analysis
composer cs-check      # Code style validation
composer cs-fix        # Automatic style fixes
composer phpstan       # Static analysis

Test Coverage Analysis: To generate detailed coverage reports, install either PCOV (recommended) or Xdebug:

# Using PCOV
pecl install pcov

# Or using Xdebug
pecl install xdebug

Contributing

We welcome contributions that improve the bundle's functionality or documentation. To contribute:

Fork the repository
Create a feature branch
Implement your changes with tests
Submit a pull request

For significant changes, please open an issue first to discuss your proposed changes.

Support and Troubleshooting

If you encounter issues or need assistance:

Check the logs in var/log/ for detailed error messages
Verify your DNS domains are correctly configured
Ensure proper file permissions for .htaccess
Open an issue on the GitHub repository with:
- Detailed description of the problem
- Relevant log entries
- Your configuration (without sensitive data)
- Steps to reproduce the issue

License

This project is licensed under the MIT License, promoting open collaboration and reuse. See the LICENSE file for complete terms.

monosize / dynamic-dns-ip-updater

Maintainers

Details