feat: client identification headers

src/Client/DefaultRegistrationService.php

@@ -22,11 +22,9 @@ public function __construct(
         private readonly ClientInterface $httpClient,
         private readonly RequestFactoryInterface $requestFactory,
         private readonly UnleashConfiguration $configuration,
-        private ?string $sdkName = null,
-        private ?string $sdkVersion = null,
+        private ?string $sdkName = Unleash::SDK_NAME,
+        private ?string $sdkVersion = Unleash::SDK_VERSION,
     ) {
-        $this->sdkName ??= 'unleash-client-php';
-        $this->sdkVersion ??= Unleash::SDK_VERSION;
     }
 
     /**
@@ -66,6 +64,11 @@ public function register(iterable $strategyHandlers): bool
             $request = $request->withHeader($name, $value);
         }
 
+        $request = $request
+            ->withHeader('x-unleash-appname', $this->configuration->getAppName())
+            ->withHeader('x-unleash-sdk', $this->sdkName . ':' . $this->sdkVersion)
+            ->withHeader('x-unleash-connection-id', $this->configuration->getConnectionId());
+
         try {
             $response = $this->httpClient->sendRequest($request);
             $result = $response->getStatusCode() >= 200 && $response->getStatusCode() < 300;

src/Configuration/UnleashConfiguration.php

@@ -14,12 +14,16 @@
 use Unleash\Client\Bootstrap\EmptyBootstrapProvider;
 use Unleash\Client\ContextProvider\DefaultUnleashContextProvider;
 use Unleash\Client\ContextProvider\UnleashContextProvider;
+use Unleash\Client\Enum\CacheKey;
 use Unleash\Client\Helper\Url;
+use Unleash\Client\Helper\Uuid;
 use Unleash\Client\Metrics\DefaultMetricsBucketSerializer;
 use Unleash\Client\Metrics\MetricsBucketSerializer;
 
 final class UnleashConfiguration
 {
+    private string $connectionId;
+
     /**
      * @param array<string,string> $headers
      */
@@ -45,6 +49,7 @@
         private MetricsBucketSerializer $metricsBucketSerializer = new DefaultMetricsBucketSerializer(),
     ) {
         $this->contextProvider ??= new DefaultUnleashContextProvider();
+        $this->connectionId = Uuid::v4();
     }
 
     public function getCache(): CacheInterface
@@ -298,4 +303,16 @@
 
         return $this;
     }
+
+    public function getConnectionId(): string
+    {
+        $cachedConnectionId = $this->getCache()->get(CacheKey::CONNECTION_ID);
+
+        return $cachedConnectionId ?? $this->connectionId;
+    }
+
+    public function updateCachedConnectionId(): void
+    {
+        $this->getCache()->set(CacheKey::CONNECTION_ID, $this->connectionId);
+    }
 }

src/Enum/CacheKey.php

@@ -14,4 +14,6 @@ final class CacheKey
     public const string REGISTRATION = 'unleash.client.metrics.registration';
 
     public const string FEATURES_RESPONSE = 'unleash.client.feature.response';
+
+    public const string CONNECTION_ID = 'unleash.client.connection.id';
 }

src/Repository/DefaultUnleashRepository.php

@@ -88,6 +88,8 @@ public function __construct(
         private ClientInterface $httpClient,
         private RequestFactoryInterface $requestFactory,
         private UnleashConfiguration $configuration,
+        private string $sdkName = Unleash::SDK_NAME,
+        private string $sdkVersion = Unleash::SDK_VERSION,
     ) {
     }
 
@@ -158,7 +160,9 @@ private function getCachedFeatures(): ?array
     private function setCache(array $features): void
     {
         $cache = $this->configuration->getCache();
-        $cache->set(CacheKey::FEATURES, $features, $this->configuration->getTtl());
+        $ttl = $this->configuration->getTtl();
+        $cache->set(CacheKey::FEATURES, $features, $ttl);
+        $this->configuration->updateCachedConnectionId();
     }
 
     /**
@@ -510,6 +514,7 @@ private function fetchFeatures(): array
         } else {
             $request = $this->requestFactory
                 ->createRequest('GET', (string) Url::appendPath($this->configuration->getUrl(), 'client/features'))
+                // TODO: remove non-standard headers
                 ->withHeader('UNLEASH-APPNAME', $this->configuration->getAppName())
                 ->withHeader('UNLEASH-INSTANCEID', $this->configuration->getInstanceId())
                 ->withHeader('Unleash-Client-Spec', Unleash::SPECIFICATION_VERSION);
@@ -518,6 +523,11 @@ private function fetchFeatures(): array
                 $request = $request->withHeader($name, $value);
             }
 
+            $request = $request
+                ->withHeader('x-unleash-appname', $this->configuration->getAppName())
+                ->withHeader('x-unleash-sdk', $this->sdkName . ':' . $this->sdkVersion)
+                ->withHeader('x-unleash-connection-id', $this->configuration->getConnectionId());
+
             try {
                 $response = $this->httpClient->sendRequest($request);
                 if ($response->getStatusCode() === 200) {

src/Unleash.php

@@ -7,6 +7,8 @@
 
 interface Unleash
 {
+    public const string SDK_NAME = 'unleash-client-php';
+
     public const string SDK_VERSION = '2.6.1';
 
     public const string SPECIFICATION_VERSION = '5.0.2';

src/UnleashBuilder.php

@@ -36,6 +36,7 @@
 use Unleash\Client\Helper\Builder\StickinessCalculatorAware;
 use Unleash\Client\Helper\DefaultImplementationLocator;
 use Unleash\Client\Helper\UnleashBuilderContainer;
+use Unleash\Client\Helper\Uuid;
 use Unleash\Client\Metrics\DefaultMetricsBucketSerializer;
 use Unleash\Client\Metrics\DefaultMetricsHandler;
 use Unleash\Client\Metrics\DefaultMetricsSender;
@@ -69,6 +70,8 @@ final class UnleashBuilder
 
     private ?string $appName = null;
 
+    private string $connectionId;
+
     private ?ClientInterface $httpClient = null;
 
     private ?RequestFactoryInterface $requestFactory = null;
@@ -131,6 +134,8 @@ public function __construct()
             $this->eventDispatcher = new EventDispatcher();
         }
 
+        $this->connectionId = Uuid::v4();
+
         $rolloutStrategyHandler = new GradualRolloutStrategyHandler(new MurmurHashCalculator());
         $this->strategies = [
             new DefaultStrategyHandler(),
@@ -406,7 +411,11 @@ public function build(): Unleash
         );
 
         assert($dependencyContainer->getConfiguration() !== null);
-        $registrationService = $this->registrationService ?? new DefaultRegistrationService($dependencyContainer->getHttpClient(), $dependencyContainer->getRequestFactory(), $dependencyContainer->getConfiguration());
+        $registrationService = $this->registrationService ?? new DefaultRegistrationService(
+            $dependencyContainer->getHttpClient(),
+            $dependencyContainer->getRequestFactory(),
+            $dependencyContainer->getConfiguration(),
+        );
         $metricsHandler = $this->metricsHandler ?? new DefaultMetricsHandler($metricsSender, $dependencyContainer->getConfiguration());
         $variantHandler = $this->variantHandler ?? new DefaultVariantHandler(new MurmurHashCalculator());
 
@@ -671,6 +680,10 @@ private function createRepository(UnleashBuilderContainer $dependencyContainer):
     {
         assert($dependencyContainer->getConfiguration() !== null);
 
-        return new DefaultUnleashRepository($dependencyContainer->getHttpClient(), $dependencyContainer->getRequestFactory(), $dependencyContainer->getConfiguration());
+        return new DefaultUnleashRepository(
+            $dependencyContainer->getHttpClient(),
+            $dependencyContainer->getRequestFactory(),
+            $dependencyContainer->getConfiguration(),
+        );
     }
 }

tests/Client/DefaultRegistrationServiceTest.php

@@ -131,4 +131,30 @@ public function testUrl()
         self::assertCount(1, $this->requestHistory);
         self::assertSame('https://localhost/api/client/register?namePrefix=somePrefix', (string) $this->requestHistory[0]['request']->getUri());
     }
+
+    public function testRequestHeaders()
+    {
+        $configuration = (new UnleashConfiguration('', 'customAppName', ''))
+            ->setCache($this->getCache())
+            ->setHeaders([
+                'Some-Header' => 'some-value',
+                'x-unleash-connection-id' => 'should not override',
+            ])->setCache($this->getCache());
+
+        $instance = new DefaultRegistrationService(
+            $this->httpClient,
+            new HttpFactory(),
+            $configuration
+        );
+        $this->pushResponse([]);
+
+        $instance->register([]);
+        self::assertCount(1, $this->requestHistory);
+
+        $request = $this->requestHistory[0]['request'];
+        self::assertSame('some-value', $request->getHeaderLine('Some-Header'));
+        self::assertEquals('customAppName', $request->getHeaderLine('x-unleash-appname'));
+        self::assertStringStartsWith('unleash-client-php:', $request->getHeaderLine('x-unleash-sdk'));
+        self::assertStringMatchesFormat('%s-%s-%s-%s-%s', $request->getHeaderLine('x-unleash-connection-id'));
+    }
 }