[ReactPHP] Add required HTTP Client Metric

src/Instrumentation/ReactPHP/README.md

@@ -9,17 +9,23 @@ This is a read-only subtree split of https://github.com/open-telemetry/opentelem
 
 # OpenTelemetry ReactPHP HTTP Browser auto-instrumentation
 
+This is an OpenTelemetry auto-instrumentation package for the [ReactPHP HTTP library](https://reactphp.org/http/). Currently only the Browser (client) component is instrumented.
+
 Please read https://opentelemetry.io/docs/instrumentation/php/automatic/ for instructions on how to
 install and configure the extension and SDK.
 
 ## Overview
 
-Auto-instrumentation hooks are registered via composer, which will:
+This library is provides the following:
 
-* create spans automatically for each ReactPHP HTTP Browser request that is sent
-* add a `traceparent` header to the request to facilitate distributed tracing
+- OpenTelemetry Semantic Conventions v1.32.0:
+    - [HTTP Client Spans](https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span) - required and HTTP header (opt-in) attributes only
+    - [HTTP Client Metrics](https://opentelemetry.io/docs/specs/semconv/http/http-metrics/#http-client) - required attributes only
+- W3C Trace Context:
+    - [Trace Context HTTP Request Headers](https://www.w3.org/TR/trace-context/#trace-context-http-headers-format)
 
-Note that span lifetime behavior differs based on how ReactPHP is utilized; see [examples/README.md](examples/README.md) for more information.
+> [!NOTE]
+> HTTP Client Span lifetime behavior differs based on how ReactPHP is utilized; see [examples/README.md](examples/README.md) for more information.
 
 ## Configuration
 

src/Instrumentation/ReactPHP/examples/http_requests_metric_only.php

@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+use OpenTelemetry\SDK\Metrics\Data\Temporality;
+use OpenTelemetry\SDK\Metrics\MeterProvider;
+use OpenTelemetry\SDK\Metrics\MetricExporter\ConsoleMetricExporter;
+use OpenTelemetry\SDK\Metrics\MetricReader\ExportingReader;
+use OpenTelemetry\SDK\Resource\ResourceInfoFactory;
+use OpenTelemetry\SDK\Sdk;
+use Psr\Http\Message\ResponseInterface;
+use React\Http\Browser;
+use React\Http\Message\Request;
+use React\Http\Message\ResponseException;
+
+require_once dirname(__DIR__) . '/vendor/autoload.php';
+
+$exporter = new ConsoleMetricExporter(Temporality::CUMULATIVE);
+
+$meterProvider = MeterProvider::builder()
+    ->addReader(new ExportingReader($exporter))
+    ->setResource(ResourceInfoFactory::emptyResource())
+    ->build();
+
+Sdk::builder()
+    ->setMeterProvider($meterProvider)
+    ->setAutoShutdown(true)
+    ->buildAndRegisterGlobal();
+
+try {
+    $browser = new Browser();
+
+    $requests = [
+        new Request('GET', 'https://postman-echo.com/get'),
+        new Request('GET', 'https://postman-echo.com/stream/33554432'),
+        new Request('POST', 'https://postman-echo.com/post', ['Content-Type' => 'application/json'], '{}'),
+        new Request('CUSTOM', 'http://postman-echo.com:443/get'),
+        new Request('GET', 'unknown://postman-echo.com/get'),
+        new Request('GET', 'https://postman-echo.com/delay/2'),
+    ];
+
+    foreach ($requests as $request) {
+        $browser
+            ->request($request->getMethod(), $request->getUri())
+            ->then(function (ResponseInterface $response) use ($request) {
+                echo sprintf(
+                    '[HTTP/%s %d %s] %s%s',
+                    $response->getProtocolVersion(),
+                    $response->getStatusCode(),
+                    $response->getReasonPhrase(),
+                    $request->getUri(),
+                    PHP_EOL
+                );
+            }, function (Throwable $t) use ($request) {
+                if (is_a($t, ResponseException::class)) {
+                    $response = $t->getResponse();
+                    echo sprintf(
+                        '[HTTP/%s %d %s] %s%s',
+                        $response->getProtocolVersion(),
+                        $response->getStatusCode(),
+                        $response->getReasonPhrase(),
+                        $request->getUri(),
+                        PHP_EOL
+                    );
+                } else {
+                    echo sprintf(
+                        '[%d: %s] %s%s',
+                        $t->getCode(),
+                        $t->getMessage(),
+                        $request->getUri(),
+                        PHP_EOL
+                    );
+                }
+            });
+    }
+} finally {
+    $meterProvider->forceFlush();
+}

src/Instrumentation/ReactPHP/src/ReactPHPInstrumentation.php

@@ -6,8 +6,11 @@
 
 use Composer\InstalledVersions;
 use GuzzleHttp\Psr7\Query;
+use OpenTelemetry\API\Common\Time\Clock;
+use OpenTelemetry\API\Common\Time\ClockInterface;
 use OpenTelemetry\API\Globals;
 use OpenTelemetry\API\Instrumentation\CachedInstrumentation;
+use OpenTelemetry\API\Metrics\Noop\NoopHistogram;
 use OpenTelemetry\API\Trace\Span;
 use OpenTelemetry\API\Trace\SpanKind;
 use OpenTelemetry\API\Trace\StatusCode;
@@ -81,6 +84,9 @@ class ReactPHPInstrumentation
 
     public static function register(): void
     {
+        /** @var \OpenTelemetry\API\Metrics\HistogramInterface|null */
+        static $histogram;
+
         $instrumentation = new CachedInstrumentation(
             self::INSTRUMENTATION_LIBRARY_NAME,
             InstalledVersions::getPrettyVersion(self::COMPOSER_NAME),
@@ -102,24 +108,28 @@ public static function register(): void
                     $request = $request->withoutHeader($field);
                 }
 
-                /** @var non-empty-string|null */
-                $method = self::canonizeMethod($request->getMethod());
+                /** @var array{'http.request.method':non-empty-string|null,'server.address':non-empty-string,'server.port':int} $requestMeta */
+                $requestMeta = [
+                    'http.request.method' => self::canonizeMethod($request->getMethod()),
+                    'server.address' => $request->getUri()->getHost(),
+                    'server.port' => $request->getUri()->getPort() ?? ($request->getUri()->getScheme() === 'https' ? 443 : 80),
+                ];
 
                 $spanBuilder = $instrumentation
                     ->tracer()
                     // https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span
-                    ->spanBuilder($method ?? self::HTTP_REQUEST_METHOD_HTTP)
+                    ->spanBuilder($requestMeta['http.request.method'] ?? self::HTTP_REQUEST_METHOD_HTTP)
                     ->setParent($parentContext)
                     ->setSpanKind(SpanKind::KIND_CLIENT)
-                    ->setAttribute(TraceAttributes::HTTP_REQUEST_METHOD, $method ?? TraceAttributeValues::HTTP_REQUEST_METHOD_OTHER)
-                    ->setAttribute(TraceAttributes::SERVER_ADDRESS, $request->getUri()->getHost())
-                    ->setAttribute(TraceAttributes::SERVER_PORT, $request->getUri()->getPort() ?? ($request->getUri()->getScheme() === 'https' ? 443 : 80))
+                    ->setAttribute(TraceAttributes::HTTP_REQUEST_METHOD, $requestMeta['http.request.method'] ?? TraceAttributeValues::HTTP_REQUEST_METHOD_OTHER)
+                    ->setAttribute(TraceAttributes::SERVER_ADDRESS, $requestMeta['server.address'])
+                    ->setAttribute(TraceAttributes::SERVER_PORT, $requestMeta['server.port'])
                     ->setAttribute(TraceAttributes::URL_FULL, self::sanitizeUrl($request->getUri()))
                     // https://opentelemetry.io/docs/specs/semconv/code/
                     ->setAttribute(TraceAttributes::CODE_FUNCTION_NAME, sprintf('%s::%s', $class, $function));
 
                 // https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span
-                if ($method === null) {
+                if ($requestMeta['http.request.method'] === null) {
                     $spanBuilder->setAttribute(TraceAttributes::HTTP_REQUEST_METHOD_ORIGINAL, $request->getMethod());
                 }
 
@@ -133,7 +143,8 @@ public static function register(): void
                     $spanBuilder->setAttribute(TraceAttributes::CODE_LINE_NUMBER, $lineno);
                 }
 
-                $span = $spanBuilder->startSpan();
+                $requestStart = Clock::getDefault()->now();
+                $span = $spanBuilder->setStartTimestamp($requestStart)->startSpan();
                 $context = $span->storeInContext($parentContext);
                 $propagator->inject($request, HeadersPropagator::instance(), $context);
 
@@ -146,11 +157,13 @@ public static function register(): void
                     }
                 }
 
-                Context::storage()->attach($context);
+                $scope = Context::storage()->attach($context);
+                $scope->offsetSet('requestMeta', $requestMeta);
+                $scope->offsetSet('requestStart', $requestStart);
 
                 return [$request];
             },
-            post: static function (Transaction $transaction, array $params, PromiseInterface $promise): PromiseInterface {
+            post: static function (Transaction $transaction, array $params, PromiseInterface $promise) use (&$histogram, $instrumentation): PromiseInterface {
                 $scope = Context::storage()->scope();
                 $scope?->detach();
 
@@ -160,21 +173,42 @@ public static function register(): void
 
                 $span = Span::fromContext($scope->context());
 
-                if (!$span->isRecording()) {
+                //https://opentelemetry.io/docs/specs/semconv/http/http-metrics/#http-client
+                $histogram ??= $instrumentation->meter()->createHistogram(
+                    'http.client.request.duration',
+                    's',
+                    'Duration of HTTP client requests.',
+                    ['ExplicitBucketBoundaries' => [0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10]]
+                );
+
+                if (!$span->isRecording() && is_a($histogram, NoopHistogram::class)) {
                     return $promise;
                 }
 
+                /** @var array{'http.request.method':non-empty-string|null,'server.address':non-empty-string,'server.port':int} $requestMeta */
+                $requestMeta = $scope->offsetGet('requestMeta');
+                $requestMeta['http.request.method'] ??= '_OTHER';
+                /** @var int $requestStart */
+                $requestStart = $scope->offsetGet('requestStart');
+
                 return $promise->then(
-                    onFulfilled: function (ResponseInterface $response) use ($span) {
+                    onFulfilled: function (ResponseInterface $response) use ($histogram, $requestMeta, $requestStart, $span) {
+                        $requestEnd = Clock::getDefault()->now();
+                        /** @var array{'http.response.status_code':int,'network.protocol.version':non-empty-string,'error.type'?:non-empty-string} $responseMeta */
+                        $responseMeta = [
+                            'http.response.status_code' => $response->getStatusCode(),
+                            'network.protocol.version' => $response->getProtocolVersion(),
+                        ];
                         // https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span
                         $span
-                            ->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $response->getStatusCode())
-                            ->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $response->getProtocolVersion());
+                            ->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $responseMeta['http.response.status_code'])
+                            ->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $responseMeta['network.protocol.version']);
 
-                        if ($response->getStatusCode() >= 400 && $response->getStatusCode() < 600) {
+                        if ($responseMeta['http.response.status_code'] >= 400 && $responseMeta['http.response.status_code'] < 600) {
                             $span
                                 ->setStatus(StatusCode::STATUS_ERROR)
-                                ->setAttribute(TraceAttributes::ERROR_TYPE, (string) $response->getStatusCode());
+                                ->setAttribute(TraceAttributes::ERROR_TYPE, (string) $responseMeta['http.response.status_code']);
+                            $responseMeta['error.type'] = (string) $responseMeta['http.response.status_code'];
                         }
 
                         foreach (explode(',', $_ENV[self::ENV_HTTP_RESPONSE_HEADERS] ?? '') as $header) {
@@ -186,19 +220,31 @@ public static function register(): void
                             }
                         }
 
-                        $span->end();
+                        $span->end($requestEnd);
+
+                        $histogram->record(
+                            (float) (($requestEnd - $requestStart) / ClockInterface::NANOS_PER_SECOND),
+                            array_merge($requestMeta, $responseMeta)
+                        );
 
                         return $response;
                     },
-                    onRejected: function (Throwable $t) use ($span) {
+                    onRejected: function (Throwable $t) use ($histogram, $requestMeta, $requestStart, $span) {
+                        $requestEnd = Clock::getDefault()->now();
                         $span->recordException($t);
                         if (is_a($t, ResponseException::class)) {
+                            /** @var array{'http.response.status_code':int,'network.protocol.version':non-empty-string,'error.type':non-empty-string} $responseMeta */
+                            $responseMeta = [
+                                'error.type' => (string) $t->getCode(),
+                                'http.response.status_code' => $t->getCode(),
+                                'network.protocol.version' => $t->getResponse()->getProtocolVersion(),
+                            ];
                             // https://opentelemetry.io/docs/specs/semconv/http/http-spans/#http-client-span
                             $span
                                 ->setStatus(StatusCode::STATUS_ERROR)
-                                ->setAttribute(TraceAttributes::ERROR_TYPE, (string) $t->getCode())
-                                ->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $t->getCode())
-                                ->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $t->getResponse()->getProtocolVersion());
+                                ->setAttribute(TraceAttributes::ERROR_TYPE, $responseMeta['error.type'])
+                                ->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $responseMeta['http.response.status_code'])
+                                ->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $responseMeta['network.protocol.version']);
 
                             foreach (explode(',', $_ENV[self::ENV_HTTP_RESPONSE_HEADERS] ?? '') as $header) {
                                 if ($t->getResponse()->hasHeader($header)) {
@@ -209,12 +255,21 @@ public static function register(): void
                                 }
                             }
                         } else {
+                            /** @var array{'error.type':non-empty-string} $responseMeta */
+                            $responseMeta = [
+                                'error.type' => $t::class,
+                            ];
                             $span
                                 ->setStatus(StatusCode::STATUS_ERROR, $t->getMessage())
-                                ->setAttribute(TraceAttributes::ERROR_TYPE, $t::class);
+                                ->setAttribute(TraceAttributes::ERROR_TYPE, $responseMeta['error.type']);
                         }
 
-                        $span->end();
+                        $span->end($requestEnd);
+
+                        $histogram->record(
+                            (float) (($requestEnd - $requestStart) / ClockInterface::NANOS_PER_SECOND),
+                            array_merge($requestMeta, $responseMeta)
+                        );
 
                         throw $t;
                     }