Getting Started

Minimal Setup

Installation Run:
```
composer require a5sys/monitor-bundle
```

Enable Bundles Add to app/AppKernel.php:

new A5sys\MonitorBundle\MonitorBundle(),
new JMS\TranslationBundle\JMSTranslationBundle(), // Required dependency

Configure Monolog In app/config/config.yml:

monolog:
    channels: ['monitor']
    handlers:
        monitor:
            type: rotating_file
            max_files: 60
            path: "%kernel.logs_dir%/monitor.log"
            channels: ['monitor']
            formatter: monitor.monolog.formatter

Exclude monitor from your main log to avoid spam:

monolog:
    handlers:
        main:
            type: rotating_file
            channels: [!'monitor']

Route Access Add to app/config/routing.yml:

monitor_controller:
    resource: "@MonitorBundle/Controller/"
    type: annotation
    prefix: /monitor

First Use Case Access /monitor in your browser (ensure security is configured). The dashboard will show:
- Unfinished requests (timeouts/errors).
- Slow requests (thresholds configurable via bundle settings).
- Performance killers (e.g., long-running queries or external API calls).

Implementation Patterns

Core Workflow

Data Collection The bundle hooks into Symfony’s event system (e.g., kernel.request, kernel.response) to log:
- Request duration.
- Response status codes (e.g., 500, 200).
- Memory usage spikes.
- Exceptions (if uncaught).

Threshold Configuration Customize performance thresholds in config.yml:

monitor:
    slow_request_threshold: 500  # ms (default)
    error_threshold: 100          # requests before alerting

Integration with Existing Logs
- Correlation IDs: Use Request::get('X-Request-ID') to trace logs across services.
- Structured Logging: Extend the monitor.monolog.formatter to include custom metadata (e.g., user IDs, request payloads).
Scheduled Reports Use Symfony’s CronBundle or a queue worker (e.g., Symfony Messenger) to:
- Parse monitor.log daily.
- Generate reports (e.g., Slack alerts for 5xx spikes).
- Archive logs via Logrotate.

Dashboard Customization Override the default controller (MonitorBundle:Controller\MonitorController) to:

Add filters (e.g., by route, user role).
Integrate with Grafana for visualization.

Example:

// src/Acme/MonitorBundle/Controller/MonitorController.php
class MonitorController extends \A5sys\MonitorBundle\Controller\MonitorController
{
    public function indexAction()
    {
        $data = parent::indexAction();
        $data['custom_metric'] = $this->getCustomMetric();
        return $this->render('AcmeMonitorBundle:monitor:index.html.twig', $data);
    }
}

API Access Expose metrics via a custom endpoint:

# app/config/routing.yml
monitor_api:
    path: /api/monitor/metrics
    defaults: { _controller: AcmeMonitorBundle:MonitorApi:metrics }

Gotchas and Tips

Pitfalls

Log Bloat
- Issue: Rotating logs (max_files: 60) may fill disk space if not monitored.
- Fix: Set up log rotation via logrotate or increase max_files temporarily during debugging.
Performance Overhead
- Issue: Logging every request adds ~1–5ms overhead. Disable in production for non-critical routes:
```
monitor:
    enabled_environments: [dev, staging]
```
- Fix: Use environment checks in the bundle’s event listeners.
Security Risks
- Issue: The /monitor route exposes sensitive data (e.g., slow queries, error stacks).
- Fix: Restrict access in security.yml:
```
access_control:
    - { path: ^/monitor, roles: [ROLE_ADMIN] }
```

Formatter Conflicts

Issue: The monitor.monolog.formatter may conflict with other bundles using the same channel.

Fix: Define a custom formatter in services.yml:

services:
    monitor.monolog.formatter:
        class: Monolog\Formatter\LineFormatter
        arguments: ["[%datetime%] %channel% %level% %message% %context%\n"]

Outdated Dependencies
- Issue: The bundle relies on JMS/TranslationBundle (last updated 2017) and Symfony 2.x.
- Fix: Fork the bundle and update dependencies if using Symfony 3.4+/4.x.

Debugging Tips

Verify Log Output Check var/logs/monitor.log for raw data:
```
tail -f var/logs/monitor.log | grep "slow_request"
```
Test Event Listeners Trigger a slow request manually:
```
// In a controller
sleep(1); // Simulate slow request
return new Response('Test');
```
Verify it appears in the dashboard.

Custom Metrics Extend the bundle’s logger service to add context:

// src/Acme/MonitorBundle/DependencyInjection/CompilerPass.php
public function process(ContainerBuilder $container)
{
    $definition = $container->findDefinition('monitor.logger');
    $definition->addMethodCall('addContext', ['custom_key', 'custom_value']);
}

Database Queries To log slow queries, patch the bundle’s QueryListener:

// Override A5sys\MonitorBundle\EventListener\QueryListener
public function onQuery(QueryEvent $event)
{
    if ($event->getStartTime() > 500) { // 500ms threshold
        $this->logger->warning('Slow query', ['query' => $event->getSql()]);
    }
}

Extension Points

Add Custom Metrics Inject metrics via the monitor.event service:

// In a controller/service
$this->get('monitor.event')->addMetric('custom_metric', ['value' => 123]);

Alerting System Hook into the monitor.log handler to send alerts:

# app/config/config.yml
monolog:
    handlers:
        monitor_alert:
            type:         fingers_crossed
            action_level: error
            handler:      nested
            excluded_404s: ~
            channels:     ['monitor']
            buffer_size:  0
            handlers:
                slack:
                    type:        stream
                    path:        "php://temp"
                    formatter:  monolog.formatter.slack
                    streams:     ["https://hooks.slack.com/..."]

Export Data Use the MonitorBundle\Service\MonitorService to fetch raw data:

$monitorService = $this->get('monitor.service');
$slowRequests = $monitorService->getSlowRequests(300); // Threshold in ms

Monitor Bundle Laravel Package