Merge pull request #163 from City-of-Helsinki/UHF-9635

UHF-9635: Custom Sentry traces_sampler callback

helfi_api_base.install

@@ -58,6 +58,16 @@ function helfi_api_base_install(bool $is_syncing = FALSE) : void {
   }
   catch (\InvalidArgumentException) {
   }
+
+  if (Drupal::moduleHandler()->moduleExists('raven')) {
+    Drupal::configFactory()->getEditable('raven.settings')
+      ->set('drush_error_handler', TRUE)
+      ->set('request_tracing', TRUE)
+      ->set('traces_sample_rate', 0.2)
+      ->set('database_tracing', TRUE)
+      ->set('twig_tracing', TRUE)
+      ->save();
+  }
 }
 
 /**

helfi_api_base.services.yml

@@ -25,6 +25,7 @@ services:
     parent: logger.channel_base
     arguments: [ 'helfi_api_base' ]
 
+  Drupal\helfi_api_base\EventSubscriber\SentryTracesSamplerSubscriber: ~
   Drupal\helfi_api_base\EventSubscriber\DisableUserPasswordSubscriber: ~
   Drupal\helfi_api_base\Features\FeatureManager: ~
 

src/EventSubscriber/SentryTracesSamplerSubscriber.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\helfi_api_base\EventSubscriber;
+
+use Drupal\raven\Event\OptionsAlter;
+use Sentry\Tracing\SamplingContext;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Overrides the Sentry traces sampler to ignore certain data.
+ */
+final class SentryTracesSamplerSubscriber implements EventSubscriberInterface {
+
+  public const DEFAULT_SAMPLE_RATE = 0.2;
+
+  /**
+   * Checks if the trace url should be ignored.
+   *
+   * @param array $data
+   *   The data.
+   *
+   * @return bool
+   *   TRUE if url should be ignored.
+   */
+  private function ignoreTracerUrl(array $data) : bool {
+    if (!isset($data['http.url'])) {
+      return FALSE;
+    }
+    $path = parse_url($data['http.url'], PHP_URL_PATH);
+
+    return str_ends_with($path, '/health');
+  }
+
+  /**
+   * Responds to OptionsAlter event.
+   *
+   * @param \Drupal\raven\Event\OptionsAlter $event
+   *   The options alter event.
+   */
+  public function setTracesSampler(OptionsAlter $event) : void {
+    $event->options['traces_sampler'] = function (SamplingContext $context) use ($event): float {
+      if ($context->getParentSampled()) {
+        // If the parent transaction (for example, a JavaScript front-end)
+        // is sampled, also sample the current transaction.
+        return 1.0;
+      }
+
+      $data = $context->getTransactionContext()?->getData();
+
+      if ($data && $this->ignoreTracerUrl($data)) {
+        return 0;
+      }
+
+      // Sample ~20% of transactions by default.
+      // @see https://docs.sentry.io/platforms/php/configuration/sampling/
+      return $event->options['traces_sample_rate'] ?? self::DEFAULT_SAMPLE_RATE;
+    };
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() : array {
+    return [
+      'Drupal\raven\Event\OptionsAlter' => ['setTracesSampler'],
+    ];
+  }
+
+}

tests/src/Kernel/EventSubscriber/SentryTracesSamplerSubscriberTest.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\helfi_api_base\Kernel\EventSubscriber;
+
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\Tests\helfi_api_base\Traits\ApiTestTrait;
+use Sentry\SentrySdk;
+
+/**
+ * Tests our custom Sentry 'traces_sampler' event subscriber.
+ *
+ * @group helfi_api_base
+ */
+class SentryTracesSamplerSubscriberTest extends KernelTestBase {
+
+  use ApiTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'user',
+    'raven',
+    'helfi_api_base',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installConfig('helfi_api_base');
+  }
+
+  /**
+   * Make sure our 'traces_sampler' is actually registered.
+   */
+  public function testSamplerIsCalled() : void {
+    $request = $this->getMockedRequest('/user/login');
+    $this->processRequest($request);
+
+    $client = SentrySdk::getCurrentHub()->getClient();
+    $sampler = $client->getOptions()->getTracesSampler();
+    $this->assertIsCallable($sampler);
+  }
+
+}

tests/src/Traits/ApiTestTrait.php

@@ -86,7 +86,12 @@ public function fromOptions(array $config = []) : Client {
    *   The response.
    */
   protected function processRequest(Request $request): Response {
-    return $this->container->get('http_kernel')->handle($request);
+    /** @var \Drupal\Core\StackMiddleware\StackedHttpKernel $kernel */
+    $kernel = $this->container->get('http_kernel');
+    $response = $kernel->handle($request);
+    $kernel->terminate($request, $response);
+
+    return $response;
   }
 
   /**

tests/src/Unit/EventSubscriber/SentryTracesSamplerSubscriberTest.php

@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\helfi_api_base\Unit\EventSubscriber;
+
+use Drupal\helfi_api_base\EventSubscriber\SentryTracesSamplerSubscriber;
+use Drupal\raven\Event\OptionsAlter;
+use Drupal\Tests\UnitTestCase;
+use Sentry\Tracing\SamplingContext;
+use Sentry\Tracing\TransactionContext;
+
+/**
+ * Tests sentry traces sample.
+ *
+ * @group helfi_api_base
+ */
+class SentryTracesSamplerSubscriberTest extends UnitTestCase {
+
+  /**
+   * Calls the sampler callback.
+   *
+   * @param array $options
+   *   The default options.
+   * @param \Sentry\Tracing\SamplingContext $context
+   *   The sampling context.
+   *
+   * @return float
+   *   The sample rate.
+   */
+  private function callSampler(array $options, SamplingContext $context) : float {
+    $sut = new SentryTracesSamplerSubscriber();
+    $sut->setTracesSampler(new OptionsAlter($options));
+
+    $this->assertIsCallable($options['traces_sampler']);
+
+    return $options['traces_sampler']($context);
+  }
+
+  /**
+   * Tests the default sample rate value.
+   */
+  public function testDefaultSamplerValue() : void {
+    $rate = $this->callSampler([], new SamplingContext());
+    $this->assertEquals(SentryTracesSamplerSubscriber::DEFAULT_SAMPLE_RATE, $rate);
+  }
+
+  /**
+   * Make sure the sample rate is inherited from parent.
+   */
+  public function testParentSampledValue() : void {
+    $rate = $this->callSampler([], (new SamplingContext())->setParentSampled(TRUE));
+    $this->assertEquals(1.0, $rate);
+  }
+
+  /**
+   * Make sure the sample rate is inherited from the setting.
+   */
+  public function testParentDefaultValue() : void {
+    $rate = $this->callSampler(['traces_sample_rate' => 0.5], (new SamplingContext()));
+    $this->assertEquals(0.5, $rate);
+  }
+
+  /**
+   * Make sure nothing is done when URL context is not set.
+   */
+  public function testTracerNoUrl() : void {
+    $transaction = new TransactionContext();
+    $transaction->setData(['something' => 'else']);
+    $context = SamplingContext::getDefault($transaction);
+    $rate = $this->callSampler([], $context);
+    $this->assertEquals(SentryTracesSamplerSubscriber::DEFAULT_SAMPLE_RATE, $rate);
+  }
+
+  /**
+   * Make sure the sample rate is set zero when we get a URL match.
+   *
+   * @dataProvider ignoreUrlData
+   */
+  public function testTracerIgnoreUrl(string $url) : void {
+    $transaction = new TransactionContext();
+    $transaction->setData(['http.url' => $url]);
+    $context = SamplingContext::getDefault($transaction);
+    $rate = $this->callSampler([], $context);
+    $this->assertEquals(0, $rate);
+  }
+
+  /**
+   * Data provider.
+   *
+   * @return array[]
+   *   The data.
+   */
+  public function ignoreUrlData() : array {
+    return [
+      ['http://localhost/fi/health'],
+      ['https://localhost/health'],
+    ];
+  }
+
+}