feat: Consume Docker system events asynchronously - #313

<?php

// filename : ./examples/listen-to-docker-events-async.php

use Docker\DockerAsync;
use Docker\Stream\ArtaxCallbackStream;

require dirname(__DIR__) . '/vendor/autoload.php';

Amp\Loop::run(function () {
    $docker = DockerAsync::create();

    /** @var ArtaxCallbackStream $events */
    $events = yield $docker->systemEvents();
    $events->onFrame(function ($event): void {
        // Do something with the docker event
        // var_dump($event);
    });

    // Start listening to Docker events
    $events->listen();

    // Close the request when a SIGINT signal is received
    Amp\Loop::onSignal(SIGINT, function (string $watcherId) use ($events) {
        $events->cancel();
        Amp\Loop::cancel($watcherId);
    });
});