handle symfony subrequests (#262)

- kind=internal
- name contains controller

Author: brettmc

composer.json

@@ -7,6 +7,7 @@
   "readme": "./README.md",
   "license": "Apache-2.0",
   "minimum-stability": "dev",
+  "prefer-stable": true,
   "require": {
     "php": "^8.0",
     "ext-opentelemetry": "*",

src/SymfonyInstrumentation.php

@@ -16,6 +16,7 @@
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\HttpKernel;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
 
 final class SymfonyInstrumentation
 {
@@ -37,11 +38,16 @@ public static function register(): void
                 ?int $lineno,
             ) use ($instrumentation): array {
                 $request = ($params[0] instanceof Request) ? $params[0] : null;
+                $type = $params[1] ?? HttpKernelInterface::MAIN_REQUEST;
+                $method = $request?->getMethod() ?? 'unknown';
+                $name = ($type === HttpKernelInterface::SUB_REQUEST)
+                    ? sprintf('%s %s', $method, $request?->attributes?->get('_controller') ?? 'sub-request')
+                    : $method;
                 /** @psalm-suppress ArgumentTypeCoercion */
                 $builder = $instrumentation
                     ->tracer()
-                    ->spanBuilder(\sprintf('%s', $request?->getMethod() ?? 'unknown'))
-                    ->setSpanKind(SpanKind::KIND_SERVER)
+                    ->spanBuilder($name)
+                    ->setSpanKind(($type === HttpKernelInterface::SUB_REQUEST) ? SpanKind::KIND_INTERNAL : SpanKind::KIND_SERVER)
                     ->setAttribute(TraceAttributes::CODE_FUNCTION, $function)
                     ->setAttribute(TraceAttributes::CODE_NAMESPACE, $class)
                     ->setAttribute(TraceAttributes::CODE_FILEPATH, $filename)

tests/Integration/AbstractTest.php

@@ -8,6 +8,7 @@
 use OpenTelemetry\API\Instrumentation\Configurator;
 use OpenTelemetry\API\Trace\Propagation\TraceContextPropagator;
 use OpenTelemetry\Context\ScopeInterface;
+use OpenTelemetry\SDK\Trace\ImmutableSpan;
 use OpenTelemetry\SDK\Trace\SpanExporter\InMemoryExporter;
 use OpenTelemetry\SDK\Trace\SpanProcessor\SimpleSpanProcessor;
 use OpenTelemetry\SDK\Trace\TracerProvider;
@@ -16,6 +17,7 @@
 abstract class AbstractTest extends TestCase
 {
     private ScopeInterface $scope;
+    /** @var ArrayObject<int, ImmutableSpan> $storage */
     protected ArrayObject $storage;
 
     public function setUp(): void

tests/Integration/SymfonyInstrumentationTest.php

@@ -4,8 +4,10 @@
 
 namespace OpenTelemetry\Tests\Instrumentation\Symfony\tests\Integration;
 
+use OpenTelemetry\API\Trace\SpanKind;
 use OpenTelemetry\Contrib\Propagation\ServerTiming\ServerTimingPropagator;
 use OpenTelemetry\Contrib\Propagation\TraceResponse\TraceResponsePropagator;
+use OpenTelemetry\SDK\Trace\ImmutableSpan;
 use OpenTelemetry\SemConv\TraceAttributes;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
@@ -164,6 +166,22 @@ public function test_http_kernel_handle_without_route(): void
         );
     }
 
+    public function test_http_kernel_handle_subrequest(): void
+    {
+        $kernel = $this->getHttpKernel(new EventDispatcher());
+        $this->assertCount(0, $this->storage);
+        $request = new Request();
+        $request->attributes->set('_controller', 'ErrorController');
+
+        $kernel->handle($request, HttpKernelInterface::SUB_REQUEST);
+        $this->assertCount(1, $this->storage);
+
+        /** @var ImmutableSpan $span */
+        $span = $this->storage[0];
+        $this->assertSame('GET ErrorController', $span->getName());
+        $this->assertSame(SpanKind::KIND_INTERNAL, $span->getKind());
+    }
+
     private function getHttpKernel(EventDispatcherInterface $eventDispatcher, $controller = null, RequestStack $requestStack = null, array $arguments = []): HttpKernel
     {
         $controller ??= fn () => new Response('Hello');