feat(agent): add AgentClient (#2062)

Author: Litarnus

src/Agent/Transport/AgentClient.php

@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sentry\Agent\Transport;
+
+use Sentry\HttpClient\HttpClientInterface;
+use Sentry\HttpClient\Request;
+use Sentry\HttpClient\Response;
+use Sentry\Options;
+
+class AgentClient implements HttpClientInterface
+{
+    /**
+     * @var string
+     */
+    private $host;
+
+    /**
+     * @var int
+     */
+    private $port;
+
+    /**
+     * @var resource|null
+     */
+    private $socket;
+
+    public function __construct(string $host = '127.0.0.1', int $port = 5148)
+    {
+        $this->host = $host;
+        $this->port = $port;
+    }
+
+    public function __destruct()
+    {
+        $this->disconnect();
+    }
+
+    /**
+     * @phpstan-assert-if-true resource $this->socket
+     */
+    private function connect(): bool
+    {
+        if ($this->socket !== null) {
+            return true;
+        }
+
+        // We set the timeout to 10ms to avoid blocking the request for too long if the agent is not running
+        // @TODO: 10ms should be low enough? Do we want to go lower and/or make this configurable? Only applies to initial connection.
+        $socket = fsockopen($this->host, $this->port, $errorNo, $errorMsg, 0.01);
+
+        // @TODO: Error handling? See $errorNo and $errorMsg
+        if ($socket === false) {
+            return false;
+        }
+
+        // @TODO: Set a timeout for the socket to prevent blocking (?) if the socket connection stops working after the connection (e.g. the agent is stopped) if needed
+        $this->socket = $socket;
+
+        return true;
+    }
+
+    private function disconnect(): void
+    {
+        if ($this->socket === null) {
+            return;
+        }
+
+        fclose($this->socket);
+
+        $this->socket = null;
+    }
+
+    private function send(string $message): void
+    {
+        if (!$this->connect()) {
+            return;
+        }
+
+        // @TODO: Make sure we don't send more than 2^32 - 1 bytes
+        $contentLength = pack('N', \strlen($message) + 4);
+
+        // @TODO: Error handling?
+        fwrite($this->socket, $contentLength . $message);
+    }
+
+    public function sendRequest(Request $request, Options $options): Response
+    {
+        $body = $request->getStringBody();
+
+        if (empty($body)) {
+            return new Response(400, [], 'Request body is empty');
+        }
+
+        $this->send($body);
+
+        // Since we are sending async there is no feedback so we always return an empty response
+        return new Response(202, [], '');
+    }
+}

tests/HttpClient/AgentClientTest.php

@@ -0,0 +1,91 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sentry\Tests\HttpClient;
+
+use PHPUnit\Framework\TestCase;
+use Sentry\Agent\Transport\AgentClient;
+use Sentry\Event;
+use Sentry\HttpClient\Request;
+use Sentry\Options;
+use Sentry\Serializer\PayloadSerializer;
+
+final class AgentClientTest extends TestCase
+{
+    use TestAgent;
+
+    protected function tearDown(): void
+    {
+        if ($this->agentProcess !== null) {
+            $this->stopTestAgent();
+        }
+    }
+
+    public function testClientHandsOffEnvelopeToLocalAgent(): void
+    {
+        $this->startTestAgent();
+
+        $envelope = $this->createEnvelope('http://public@example.com/1', 'Hello from agent client test!');
+
+        $request = new Request();
+        $request->setStringBody($envelope);
+
+        $client = new AgentClient('127.0.0.1', $this->agentPort);
+        $response = $client->sendRequest($request, new Options());
+
+        $this->waitForEnvelopeCount(1);
+        $agentOutput = $this->stopTestAgent();
+
+        $this->assertSame(202, $response->getStatusCode());
+        $this->assertSame('', $response->getError());
+        $this->assertCount(1, $agentOutput['messages']);
+        $this->assertStringContainsString('Hello from agent client test!', $agentOutput['messages'][0]);
+        $this->assertStringContainsString('"type":"event"', $agentOutput['messages'][0]);
+    }
+
+    public function testClientReturnsAcceptedWhenLocalAgentIsUnavailable(): void
+    {
+        $envelope = $this->createEnvelope('http://public@example.com/1', 'Hello from unavailable agent test!');
+
+        $request = new Request();
+        $request->setStringBody($envelope);
+
+        $client = new AgentClient('127.0.0.1', 65001);
+
+        set_error_handler(static function (): bool {
+            return true;
+        });
+
+        try {
+            $response = $client->sendRequest($request, new Options());
+        } finally {
+            restore_error_handler();
+        }
+
+        $this->assertSame(202, $response->getStatusCode());
+        $this->assertSame('', $response->getError());
+    }
+
+    public function testClientReturnsErrorWhenBodyIsEmpty(): void
+    {
+        $client = new AgentClient();
+        $response = $client->sendRequest(new Request(), new Options());
+
+        $this->assertSame(400, $response->getStatusCode());
+        $this->assertTrue($response->hasError());
+        $this->assertSame('Request body is empty', $response->getError());
+    }
+
+    private function createEnvelope(string $dsn, string $message): string
+    {
+        $options = new Options(['dsn' => $dsn]);
+
+        $event = Event::createEvent();
+        $event->setMessage($message);
+
+        $serializer = new PayloadSerializer($options);
+
+        return $serializer->serialize($event);
+    }
+}