Telegram Notification Bot for Critical Site Events

Developing a Telegram Bot for Critical Site Event Notifications

Monitoring critical events via Telegram is a quick way to get alerts about website problems on mobile phone, bypassing email and monitoring systems. Bot notifies: site went down, payment error, disk full, 500 errors appeared.

Event Types

// List of critical events with importance levels
enum AlertLevel: string {
    case CRITICAL = '🔴';  // requires immediate action
    case WARNING  = '🟡';  // requires attention
    case INFO     = '🔵';  // informational
}

class SiteEventAlerter
{
    public function alert(AlertLevel $level, string $event, array $context = []): void
    {
        $message = "{$level->value} <b>{$event}</b>\n\n";

        foreach ($context as $key => $value) {
            $message .= "<b>{$key}:</b> {$value}\n";
        }

        $message .= "\n⏰ " . now()->format('d.m.Y H:i:s');

        // Critical events — personal messages to on-call engineer
        $recipients = $level === AlertLevel::CRITICAL
            ? $this->getOnCallEngineers()
            : [$this->alertsChannelId];

        foreach ($recipients as $chatId) {
            $this->telegram->sendMessage($chatId, $message);
        }
    }
}

Integration into Code

// In exception handler (Handler.php)
public function report(Throwable $exception): void
{
    if ($exception instanceof PaymentException) {
        app(SiteEventAlerter::class)->alert(
            AlertLevel::CRITICAL,
            'Payment gateway error',
            [
                'Gateway' => $exception->getGateway(),
                'Order'   => $exception->getOrderId(),
                'Error'   => $exception->getMessage(),
            ]
        );
    }

    parent::report($exception);
}

// In scheduler (Kernel.php)
$schedule->call(function () {
    $freeSpace = disk_free_space('/') / disk_total_space('/') * 100;
    if ($freeSpace < 10) {
        app(SiteEventAlerter::class)->alert(
            AlertLevel::WARNING,
            'Low disk space',
            ['Free' => round($freeSpace, 1) . '%']
        );
    }
})->hourly();

Anti-Spam

Same error can generate hundreds of alerts per minute. Deduplication via Redis:

private function shouldSend(string $eventKey): bool
{
    $cacheKey = "alert_dedup:{$eventKey}";
    if (Cache::has($cacheKey)) return false;
    Cache::put($cacheKey, 1, now()->addMinutes(15));
    return true;
}

Timeline: 1–2 business days.