Allow using the tracer instance from context, append Trace-Id to Response Header

[huangdijia]

子协程里需要创建新的 tracer，在协程结束的时候执行 $tracer->flush()，防止 span 丢失或者在 finish 之前就被上报了。

#5003

创建子协程的时候需要处理一下。

<?php

declare(strict_types=1);

namespace App\Kernel\Context;

use App\Kernel\Log\AppendRequestIdProcessor;
use Hyperf\Context\Context;
use Hyperf\Contract\StdoutLoggerInterface;
use Hyperf\Engine\Coroutine as Co;
use OpenTracing\Span;
use OpenTracing\Tracer;
use Psr\Container\ContainerInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Log\LoggerInterface;
use Sentry\SentrySdk;
use Throwable;

use function Hyperf\Support\call;
use function Hyperf\Support\make;

class Coroutine
{
    protected LoggerInterface $logger;

    public function __construct(protected ContainerInterface $container)
    {
        $this->logger = $container->get(StdoutLoggerInterface::class);
    }

    /**
     * @return int Returns the coroutine ID of the coroutine just created.
     *             Returns -1 when coroutine create failed.
     */
    public function create(callable $callable): int
    {
        $id = Co::id();
        $root = Context::get('tracer.root');

        $coroutine = Co::create(function () use ($callable, $id, $root) {
            try {
                // Shouldn't copy all contexts to avoid socket already been bound to another coroutine.
                Context::copy($id, [
                    AppendRequestIdProcessor::REQUEST_ID,
                    ServerRequestInterface::class,
                    SentrySdk::class,
                ]);

                // Tracer
                if ($root instanceof Span) {
                    /** @var Tracer $tracer */
                    $tracer = make(Tracer::class);
                    Context::set('tracer.tracer', $tracer);
                    $child = $tracer->startSpan('coroutine', [
                        'child_of' => $root->getContext(),
                    ]);
                    $child->setTag('coroutine.id', Co::id());
                    Context::set('tracer.root', $child);
                    Co::defer(function () use ($child, $tracer) {
                        $child->finish();
                        $tracer->flush();
                    });
                }

                call($callable);
            } catch (Throwable $throwable) {
                if (isset($child)) {
                    $child->setTag('error', true);
                    $child->log(['message', $throwable->getMessage(), 'code' => $throwable->getCode(), 'stacktrace' => $throwable->getTraceAsString()]);
                }
                $this->logger->warning((string) $throwable);
            }
        });

        try {
            return $coroutine->getId();
        } catch (Throwable $throwable) {
            $this->logger->warning((string) $throwable);
            return -1;
        }
    }
}