fix(flow-php/symfony-telemetry-bundle): optional http-foundation telemetry bridge

documentation/installation/packages/symfony-telemetry-bundle.md

@@ -20,7 +20,6 @@ composer require flow-php/symfony-telemetry-bundle:~--FLOW_PHP_VERSION--
 ## Core Dependencies
 
 - [flow-php/telemetry](/documentation/installation/packages/telemetry.md)
-- [flow-php/symfony-http-foundation-telemetry-bridge](/documentation/installation/packages/symfony-http-foundation-telemetry-bridge.md)
 - [symfony/config](https://packagist.org/packages/symfony/config)
 - [symfony/console](https://packagist.org/packages/symfony/console)
 - [symfony/dependency-injection](https://packagist.org/packages/symfony/dependency-injection)
@@ -29,6 +28,7 @@ composer require flow-php/symfony-telemetry-bundle:~--FLOW_PHP_VERSION--
 ## Suggested Dependencies
 
 - [flow-php/symfony-postgresql-bundle](/documentation/installation/packages/symfony-postgresql-bundle.md) — for PostgreSQL database management and migrations with telemetry support
+- [flow-php/symfony-http-foundation-telemetry-bridge](/documentation/installation/packages/symfony-http-foundation-telemetry-bridge.md) — for HTTP trace context propagation (extract incoming / inject outgoing W3C trace headers)
 - [flow-php/psr18-telemetry-bridge](/documentation/installation/packages/psr18-telemetry-bridge.md) — for PSR-18 HTTP client tracing
 - [flow-php/telemetry-otlp-bridge](/documentation/installation/packages/telemetry-otlp-bridge.md) — for OTLP exporter support
 - [symfony/messenger](https://packagist.org/packages/symfony/messenger) — for Messenger tracing middleware

documentation/upgrading.md

@@ -11,15 +11,18 @@ Please follow the instructions for your specific version to ensure a smooth upgr
 
 ### 1) Removal of Elasticsearch Adapter
 
-The Elasticsearch adapter has been removed from Flow PHP and replaced by the [SEAL](https://php-cmsig.github.io/search/) adapter (`flow-php/etl-adapter-seal`), a search engine abstraction layer that supports Elasticsearch, OpenSearch, Meilisearch, Solr, Typesense, Algolia, RediSearch and Loupe.
+The Elasticsearch adapter has been removed from Flow PHP and replaced by the [SEAL](https://php-cmsig.github.io/search/)
+adapter (`flow-php/etl-adapter-seal`), a search engine abstraction layer that supports Elasticsearch, OpenSearch,
+Meilisearch, Solr, Typesense, Algolia, RediSearch and Loupe.
 
 To migrate, install the SEAL adapter together with the engine adapter for your backend:
 
 ```
 composer require flow-php/etl-adapter-seal cmsig/seal-elasticsearch-adapter
 ```
 
-Then build a `CmsIg\Seal\Engine` and pass it to `to_seal_upsert()` instead of the previous `to_es_bulk_index()` (or Meilisearch) DSL functions:
+Then build a `CmsIg\Seal\Engine` and pass it to `to_seal_upsert()` instead of the previous `to_es_bulk_index()` (or
+Meilisearch) DSL functions:
 
 ```php
 use CmsIg\Seal\Engine;
@@ -38,6 +41,21 @@ data_frame()
     ->run();
 ```
 
+### 2) `flow-php/symfony-telemetry-bundle` -
+
+`flow-php/symfony-http-foundation-telemetry-bridge` is now an optional dependency
+
+| Before                               | After                                                       |
+|--------------------------------------|-------------------------------------------------------------|
+| installed transitively by the bundle | install explicitly to enable HTTP trace context propagation |
+
+`instrumentation.http_kernel.context_propagation` is silently disabled when the bridge is absent. To keep extracting
+incoming and injecting outgoing W3C trace headers:
+
+```
+composer require flow-php/symfony-http-foundation-telemetry-bridge
+```
+
 ---
 
 ## Upgrading from 0.39.x to 0.40.x

src/bridge/symfony/telemetry-bundle/composer.json

@@ -17,7 +17,6 @@
     "require": {
         "php": "~8.3.0 || ~8.4.0 || ~8.5.0",
         "flow-php/psr3-telemetry-bridge": "self.version",
-        "flow-php/symfony-http-foundation-telemetry-bridge": "self.version",
         "flow-php/telemetry": "self.version",
         "psr/clock": "^1.0",
         "symfony/config": "^6.4 || ^7.4 || ^8.0",
@@ -32,6 +31,7 @@
         "composer/semver": "^3.4",
         "doctrine/dbal": "^4.4",
         "flow-php/psr18-telemetry-bridge": "self.version",
+        "flow-php/symfony-http-foundation-telemetry-bridge": "self.version",
         "flow-php/telemetry-otlp-bridge": "self.version",
         "nyholm/psr7": "^1.8",
         "symfony/framework-bundle": "^6.4 || ^7.4 || ^8.0",
@@ -44,6 +44,7 @@
     "suggest": {
         "doctrine/dbal": "Required for Doctrine DBAL tracing (^4.4)",
         "flow-php/psr18-telemetry-bridge": "Required for PSR-18 HTTP client tracing",
+        "flow-php/symfony-http-foundation-telemetry-bridge": "Required for HTTP trace context propagation (extract incoming / inject outgoing W3C trace headers)",
         "flow-php/telemetry-otlp-bridge": "Required for OTLP exporter support",
         "symfony/messenger": "Required for Messenger tracing middleware",
         "symfony/web-profiler-bundle": "Required for the dev-only Flow Telemetry Web Profiler panel",

src/bridge/symfony/telemetry-bundle/src/Flow/Bridge/Symfony/TelemetryBundle/FlowTelemetryBundle.php

@@ -131,6 +131,8 @@ final class FlowTelemetryBundle extends AbstractBundle
 
     private const string HTTP_CLIENT_INTERFACE = 'Symfony\\Contracts\\HttpClient\\HttpClientInterface';
 
+    private const string HTTP_FOUNDATION_REQUEST_CARRIER = 'Flow\\Bridge\\Symfony\\HttpFoundationTelemetry\\RequestCarrier';
+
     private const string MESSENGER_MIDDLEWARE_INTERFACE = 'Symfony\\Component\\Messenger\\Middleware\\MiddlewareInterface';
 
     private const string PSR18_CLIENT_INTERFACE = 'Psr\\Http\\Client\\ClientInterface';
@@ -471,7 +473,7 @@ public function configure(DefinitionConfigurator $definition): void
             ->end()
             ->end()
             ->booleanNode('context_propagation')
-            ->info('Enable context propagation from incoming HTTP headers (requires propagator)')
+            ->info('Extract trace context from incoming request headers and inject it into outgoing response headers (requires flow-php/symfony-http-foundation-telemetry-bridge; silently disabled when absent)')
             ->defaultTrue()
             ->end()
             ->end()
@@ -2537,7 +2539,7 @@ private function registerInstrumentation(array $config, ContainerConfigurator $c
             );
             $builder->setParameter(
                 'flow.telemetry.http_kernel.context_propagation',
-                $httpKernelConfig['context_propagation'] ?? true,
+                ($httpKernelConfig['context_propagation'] ?? true) && class_exists(self::HTTP_FOUNDATION_REQUEST_CARRIER),
             );
             $container->import(__DIR__ . '/Resources/config/instrumentation/http_kernel.php');
         }

src/bridge/symfony/telemetry-bundle/src/Flow/Bridge/Symfony/TelemetryBundle/Instrumentation/HttpKernel/HttpKernelSpanSubscriber.php

@@ -6,10 +6,12 @@
 
 use Closure;
 use DateTimeImmutable;
+use Flow\Bridge\Symfony\HttpFoundationTelemetry\RequestCarrier;
+use Flow\Bridge\Symfony\HttpFoundationTelemetry\ResponseCarrier;
 use Flow\Telemetry\Context\Context;
 use Flow\Telemetry\Context\ContextStorage;
 use Flow\Telemetry\PackageVersion;
-use Flow\Telemetry\Propagation\ArrayCarrier;
+use Flow\Telemetry\Propagation\PropagationContext;
 use Flow\Telemetry\Propagation\Propagator;
 use Flow\Telemetry\Telemetry;
 use Flow\Telemetry\Tracer\Span;
@@ -18,6 +20,7 @@
 use Flow\Telemetry\Tracer\Tracer;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\ControllerEvent;
 use Symfony\Component\HttpKernel\Event\ExceptionEvent;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
@@ -48,7 +51,7 @@ public function __construct(
         array $excludePaths,
         private ContextStorage $contextStorage,
         private Propagator $propagator,
-        private bool $extractContext = true,
+        private bool $contextPropagation = true,
     ) {
         $this->excludePathRules = array_map(
             static fn(array $config): PathExclusionRule => PathExclusionRule::fromConfig($config),
@@ -111,7 +114,7 @@ public function onRequest(RequestEvent $event): void
             return;
         }
 
-        if ($event->isMainRequest() && $this->extractContext) {
+        if ($event->isMainRequest() && $this->contextPropagation) {
             $this->extractContextFromRequest($request);
         }
 
@@ -149,6 +152,10 @@ public function onResponse(ResponseEvent $event): void
         } else {
             $span->setStatus(SpanStatus::ok());
         }
+
+        if ($event->isMainRequest() && $this->contextPropagation) {
+            $this->injectContextIntoResponse($span, $response);
+        }
     }
 
     public function onTerminate(TerminateEvent $event): void
@@ -173,16 +180,7 @@ public function onTerminate(TerminateEvent $event): void
 
     private function extractContextFromRequest(Request $request): void
     {
-        $headers = [];
-
-        foreach ($request->headers->all() as $key => $values) {
-            if (count($values) > 0 && is_string($values[0])) {
-                $headers[$key] = $values[0];
-            }
-        }
-
-        $carrier = new ArrayCarrier($headers);
-        $propagationContext = $this->propagator->extract($carrier);
+        $propagationContext = $this->propagator->extract(new RequestCarrier($request));
 
         $spanContext = $propagationContext->spanContext;
 
@@ -198,6 +196,13 @@ private function extractContextFromRequest(Request $request): void
         }
     }
 
+    private function injectContextIntoResponse(Span $span, Response $response): void
+    {
+        $propagationContext = new PropagationContext($span->context(), $this->contextStorage->current()->baggage);
+
+        $this->propagator->inject($propagationContext, new ResponseCarrier($response));
+    }
+
     /**
      * @param array<int, object|string>|callable|object $controller
      */

src/bridge/symfony/telemetry-bundle/src/Flow/Bridge/Symfony/TelemetryBundle/Resources/views/Collector/telemetry.html.twig

@@ -174,7 +174,10 @@
     {% if collector.metrics is empty %}
         <div class="empty"><p>No metrics were recorded for this request.</p></div>
     {% else %}
-        <table>
+        <style>
+            .flow-metrics tr.sf-toggle-content.sf-toggle-visible { display: table-row; }
+        </style>
+        <table class="flow-metrics">
             <thead>
                 <tr>
                     <th>Name</th>
@@ -198,12 +201,16 @@
                                 —
                             {% else %}
                                 <a class="btn btn-link text-small sf-toggle" data-toggle-selector="#metric-attr-{{ loop.index }}" data-toggle-alt-content="Hide attributes">Attributes ({{ metric.attributes|length }})</a>
-                                <div id="metric-attr-{{ loop.index }}" class="hidden">
-                                    {{ _self.attribute_table(metric.attributes) }}
-                                </div>
                             {% endif %}
                         </td>
                     </tr>
+                    {% if metric.attributes is not empty %}
+                        <tr id="metric-attr-{{ loop.index }}" class="hidden">
+                            <td colspan="6">
+                                {{ _self.attribute_table(metric.attributes) }}
+                            </td>
+                        </tr>
+                    {% endif %}
                 {% endfor %}
             </tbody>
         </table>

src/bridge/symfony/telemetry-bundle/tests/Flow/Bridge/Symfony/TelemetryBundle/Tests/Integration/Instrumentation/HttpKernel/HttpKernelSpanSubscriberTest.php

@@ -572,4 +572,113 @@ public function test_traces_successful_http_request(): void
         static::assertSame('test_index', $attributes['http.route']);
         static::assertSame(TestController::class . '::index', $attributes['controller']);
     }
+
+    public function test_injects_context_into_response_when_propagation_enabled(): void
+    {
+        $kernel = $this->bootKernel([
+            'config' => static function (TestKernel $kernel): void {
+                $kernel->addTestBundle(FrameworkBundle::class);
+                $kernel->addTestExtensionConfig('framework', [
+                    'router' => [
+                        'utf8' => true,
+                        'resource' => __DIR__ . '/../../../Fixtures/config/routes.php',
+                    ],
+                    'http_method_override' => false,
+                    'handle_all_throwables' => true,
+                ]);
+                $kernel->addTestExtensionConfig('flow_telemetry', [
+                    'resource' => [],
+                    'exporters' => ['memory' => ['memory' => null], 'void' => ['void' => null]],
+                    'tracer_provider' => [
+                        'processor' => [
+                            'type' => 'memory',
+                            'exporter' => 'memory',
+                        ],
+                    ],
+                    'instrumentation' => [
+                        'http_kernel' => [
+                            'enabled' => true,
+                            'context_propagation' => true,
+                        ],
+                        'console' => ['enabled' => false],
+                        'messenger' => false,
+                    ],
+                ]);
+            },
+        ]);
+
+        $container = $this->getContainer();
+
+        /** @var Router $router */
+        $router = $container->get('router');
+        $routes = $router->getRouteCollection();
+        $routes->add('test_index', new Route('/test', ['_controller' => TestController::class . '::index']));
+
+        $request = Request::create('/test', 'GET');
+        $response = $kernel->handle($request);
+        $kernel->terminate($request, $response);
+
+        static::assertSame(200, $response->getStatusCode());
+
+        /** @var MemorySpanProcessor $processor */
+        $processor = $container->get('flow.telemetry.tracer_provider.processor');
+        $spans = $processor->endedSpans();
+
+        static::assertCount(1, $spans);
+
+        $span = $spans[0];
+        static::assertSame(
+            "00-{$span->context()->traceId->toHex()}-{$span->context()->spanId->toHex()}-01",
+            $response->headers->get('traceparent'),
+        );
+    }
+
+    public function test_does_not_inject_context_into_response_when_propagation_disabled(): void
+    {
+        $kernel = $this->bootKernel([
+            'config' => static function (TestKernel $kernel): void {
+                $kernel->addTestBundle(FrameworkBundle::class);
+                $kernel->addTestExtensionConfig('framework', [
+                    'router' => [
+                        'utf8' => true,
+                        'resource' => __DIR__ . '/../../../Fixtures/config/routes.php',
+                    ],
+                    'http_method_override' => false,
+                    'handle_all_throwables' => true,
+                ]);
+                $kernel->addTestExtensionConfig('flow_telemetry', [
+                    'resource' => [],
+                    'exporters' => ['memory' => ['memory' => null], 'void' => ['void' => null]],
+                    'tracer_provider' => [
+                        'processor' => [
+                            'type' => 'memory',
+                            'exporter' => 'memory',
+                        ],
+                    ],
+                    'instrumentation' => [
+                        'http_kernel' => [
+                            'enabled' => true,
+                            'context_propagation' => false,
+                        ],
+                        'console' => ['enabled' => false],
+                        'messenger' => false,
+                    ],
+                ]);
+            },
+        ]);
+
+        $container = $this->getContainer();
+
+        /** @var Router $router */
+        $router = $container->get('router');
+        $routes = $router->getRouteCollection();
+        $routes->add('test_index', new Route('/test', ['_controller' => TestController::class . '::index']));
+
+        $request = Request::create('/test', 'GET');
+        $response = $kernel->handle($request);
+        $kernel->terminate($request, $response);
+
+        static::assertSame(200, $response->getStatusCode());
+        static::assertFalse($response->headers->has('traceparent'));
+    }
 }