如何用Laravel 5创建命令定期检查BitMEX WebSocket API

Let’s walk through building this Laravel command step by step—here’s a practical, battle-tested approach based on similar WebSocket integrations I’ve done:

First, generate a new Artisan command to house our WebSocket check logic:

php artisan make:command CheckBitMEXWebSocket

Open the generated file at app/Console/Commands/CheckBitMEXWebSocket.php and update the signature and description to make it clear what the command does:

protected $signature = 'bitmex:check-websocket';
protected $description = 'Periodically validate the BitMEX real-time WebSocket connection';

Laravel doesn’t include a built-in WebSocket client, so we’ll use ratchet/pawl—a robust async WebSocket client for PHP. Install it via Composer:

composer require ratchet/pawl

Now, add the core connection logic to the handle() method of your command. We’ll connect to BitMEX’s WebSocket, subscribe to a test channel (to confirm data flow), add timeout handling, and capture errors:

use Ratchet\Client\WebSocket;
use React\EventLoop\Factory;
use Illuminate\Support\Facades\Log;

public function handle()
{
    $loop = Factory::create();
    $websocketUrl = 'wss://www.bitmex.com/realtime';
    $subscribeChannel = 'instrument:XBTUSD'; // BTC/USD instrument data
    $timeout = 10; // 10-second timeout to avoid hanging

    \Ratchet\Client\connect($websocketUrl, [], [], $loop)->then(function (WebSocket $conn) use ($subscribeChannel, $loop, $timeout) {
        // Send a subscription request to BitMEX
        $conn->send(json_encode([
            'op' => 'subscribe',
            'args' => [$subscribeChannel]
        ]));

        // Handle incoming messages
        $conn->on('message', function ($msg) use ($conn) {
            $data = json_decode($msg, true);
            
            $this->info('Received valid data from BitMEX: ' . substr($msg, 0, 100) . '...');
            
            // Verify the connection is working by checking for expected data
            if (isset($data['table']) && $data['table'] === 'instrument') {
                $this->info('✅ BitMEX WebSocket connection is functional.');
                Log::info('BitMEX WebSocket check passed');
                $conn->close(); // Close after successful validation
            }
        });

        // Handle normal connection closure
        $conn->on('close', function ($code = null, $reason = null) {
            if ($code === 1000) {
                $this->info('Connection closed after successful check.');
            } else {
                $this->error("❌ Connection closed unexpectedly (code {$code}): {$reason}");
                Log::error('BitMEX WebSocket closed unexpectedly', ['code' => $code, 'reason' => $reason]);
            }
        });

        // Handle connection errors
        $conn->on('error', function (\Exception $e) use ($loop) {
            $this->error("❌ WebSocket error: {$e->getMessage()}");
            Log::error('BitMEX WebSocket error', ['error' => $e->getMessage()]);
            $loop->stop();
        });

        // Add timeout to prevent infinite waiting
        $loop->addTimer($timeout, function () use ($conn) {
            $this->error("❌ WebSocket check timed out after {$timeout} seconds.");
            Log::error('BitMEX WebSocket check timed out');
            $conn->close();
        });
    }, function (\Exception $e) use ($loop) {
        $this->error("❌ Failed to connect to BitMEX WebSocket: {$e->getMessage()}");
        Log::error('BitMEX WebSocket connection failed', ['error' => $e->getMessage()]);
        $loop->stop();
    });

    $loop->run();
}

To run this check on a schedule, open app/Console/Kernel.php and add the command to the schedule() method. For example, to run it every 5 minutes:

protected function schedule(Schedule $schedule)
{
    $schedule->command('bitmex:check-websocket')->everyFiveMinutes();
    // Adjust frequency as needed: everyMinute(), hourly(), dailyAt('09:00'), etc.
}

Don’t forget to set up the Laravel scheduler cron job on your server to trigger these scheduled tasks:

* * * * * cd /path-to-your-laravel-project && php artisan schedule:run >> /dev/null 2>&1

• Configuration: Move WebSocket URL, channels, and timeout to config/services.php for easy updates:

  // config/services.php
  'bitmex' => [
      'websocket_url' => env('BITMEX_WEBSOCKET_URL', 'wss://www.bitmex.com/realtime'),
      'subscribe_channels' => ['instrument:XBTUSD'],
      'timeout' => env('BITMEX_WEBSOCKET_TIMEOUT', 10),
  ]
  

  Then reference these values in your command with config('services.bitmex.websocket_url').

• Alerts: Add notifications (email, Slack, etc.) for failed checks. For example, using Laravel’s mail facade:

  // Inside the error handling blocks
  \Illuminate\Support\Facades\Mail::to('your-alert-email@example.com')->send(new \App\Mail\BitMEXWebSocketFailure($e));
  

• Testing: Run the command manually first to validate it works:

  php artisan bitmex:check-websocket
  

内容的提问来源于stack exchange，提问作者user3489502