Merge pull request #29 from nenad/patch/decorate-event-subscriber-guzzle

Decorate the Guzzle5 event subscriber with more information
nenad · Sep 12, 2019 · 737e4d6 · 737e4d6
2 parents aafcac5 + bc90ba5
commit 737e4d6
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Showing 4 changed files with 105 additions and 50 deletions.
diff --git a/src/Trace/Integrations/Guzzle/EventSubscriber.php b/src/Trace/Integrations/Guzzle/EventSubscriber.php
@@ -26,6 +26,7 @@
 use GuzzleHttp\Event\BeforeEvent;
 use GuzzleHttp\Event\EndEvent;
 use GuzzleHttp\Event\SubscriberInterface;
+use OpenCensus\Trace\Tracer\TracerInterface;
 
 /**
  * This class handles integration with GuzzleHttp 5. Attaching this EventSubscriber to
@@ -48,21 +49,35 @@ class EventSubscriber implements SubscriberInterface
      * @var PropagatorInterface
      */
     private $propagator;
-
+    /**
+     * @var TracerInterface
+     */
+    private $tracer;
+    /**
+     * @var bool
+     */
+    private $logBody;
     /**
      * @var Scope
      */
     private $scope;
+    /**
+     * @var Span
+     */
+    private $span;
 
     /**
      * Create a new Guzzle event listener that creates trace spans and propagates the current
      * trace context to the downstream request.
      *
+     * @param TracerInterface $tracer
      * @param PropagatorInterface $propagator Interface responsible for serializing trace context
      */
-    public function __construct(PropagatorInterface $propagator = null)
+    public function __construct(TracerInterface $tracer, PropagatorInterface $propagator = null, bool $logBody = true)
     {
         $this->propagator = $propagator ?: new HttpHeaderPropagator();
+        $this->tracer = $tracer;
+        $this->logBody = $logBody;
     }
 
     /**
@@ -87,22 +102,25 @@ public function getEvents()
     public function onBefore(BeforeEvent $event)
     {
         $request = $event->getRequest();
-        $context = Tracer::spanContext();
-        if ($context->enabled()) {
-            $headers = new ArrayHeaders();
-            $this->propagator->inject($context, $headers);
-            $request->setHeaders($headers->toArray());
+        $headers = new ArrayHeaders();
+        $this->propagator->inject($this->tracer->spanContext(), $headers);
+        $request->setHeaders($headers->toArray());
+
+        $attrHeaders = [];
+        foreach ($request->getHeaders() as $name => $values) {
+            $attrHeaders['request.' . $name] = implode(', ', $values);
         }
 
-        $span = Tracer::startSpan([
-            'name' => 'GuzzleHttp::request',
+        $this->span = $this->tracer->startSpan([
+            'name' => sprintf('Guzzle: %s', $request->getHost()),
             'attributes' => [
-                'method' => $request->getMethod(),
-                'uri' => $request->getUrl()
-            ],
-            'kind' => Span::KIND_CLIENT
+                    'http.method' => $request->getMethod(),
+                    'http.uri' => $request->getUrl(),
+                ] + $attrHeaders,
+            'kind' => Span::KIND_CLIENT,
+            'sameProcessAsParentSpan' => !empty($this->spans),
         ]);
-        $this->scope = Tracer::withSpan($span);
+        $this->scope = $this->tracer->withSpan($this->span);
     }
 
     /**
@@ -113,6 +131,43 @@ public function onBefore(BeforeEvent $event)
      */
     public function onEnd(EndEvent $event)
     {
+        $response = $event->getResponse();
+        $exception = $event->getException();
+
+        if ($exception) {
+            $this->span->addAttribute('error', 'true');
+            $this->span->addAttribute('exception', sprintf('%s: %s', get_class($exception), $exception->getMessage()));
+        }
+
+        if ($response === null) {
+            $this->scope->close();
+            return;
+        }
+
+        $statusCode = $response->getStatusCode();
+        $this->span->addAttribute('http.status_code', (string)$statusCode);
+
+        // If it's an error, annotate it as such
+        if ($statusCode >= 400) {
+            $this->span->addAttribute('error', 'true');
+        }
+
+        if ($this->logBody) {
+            $bodyLength = (int)$response->getHeader('Content-Length');
+            if ($bodyLength > 0 && $bodyLength <= 4096) {
+                $body = (string)$response->getBody();
+            } else {
+                $body = 'Either Content-Length is missing, or it is bigger than 4096';
+            }
+            $this->span->addAttribute('response.body', $body);
+        }
+
+        $attrHeaders = [];
+        foreach ($response->getHeaders() as $name => $values) {
+            $attrHeaders['response.' . $name] = implode(', ', $values);
+        }
+        $this->span->addAttributes($attrHeaders);
+
         $this->scope->close();
     }
 }
diff --git a/tests/integration/guzzle5/composer.json b/tests/integration/guzzle5/composer.json
@@ -1,6 +1,6 @@
 {
     "require": {
-        "php": "^7.2",
+        "php": "^7.0",
         "opencensus/opencensus": "dev-master",
         "guzzlehttp/guzzle": "^5.0",
         "ext-opencensus": "*"

diff --git a/tests/integration/guzzle5/phpunit.xml.dist b/tests/integration/guzzle5/phpunit.xml.dist
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit bootstrap="./vendor/autoload.php" colors="true">
   <testsuites>
-    <testsuite>
+    <testsuite name="guzzle">
       <directory>tests</directory>
     </testsuite>
   </testsuites>

diff --git a/tests/integration/guzzle5/tests/Guzzle5Test.php b/tests/integration/guzzle5/tests/Guzzle5Test.php
@@ -20,6 +20,9 @@
 use GuzzleHttp\Client;
 use HttpTest\HttpTestServer;
 use OpenCensus\Trace\Exporter\NullExporter;
+use OpenCensus\Trace\Propagator\HttpHeaderPropagator;
+use OpenCensus\Trace\RequestHandler;
+use OpenCensus\Trace\Sampler\AlwaysSampleSampler;
 use OpenCensus\Trace\Tracer;
 use OpenCensus\Trace\Integrations\Guzzle\EventSubscriber;
 use Psr\Http\Message\RequestInterface;
@@ -37,16 +40,11 @@ public function setUp()
     {
         parent::setUp();
         $this->client = new Client();
-        $subscriber = new EventSubscriber();
-        $this->client->getEmitter()->attach($subscriber);
         if (extension_loaded('opencensus')) {
             opencensus_trace_clear();
         }
     }
 
-    /**
-     * @runInSeparateProcess
-     */
     public function testGuzzleRequest()
     {
         $server = HttpTestServer::create(
@@ -57,32 +55,31 @@ function (RequestInterface $request, ResponseInterface &$response) {
             }
         );
 
-        $exporter = new NullExporter();
-        $tracer = Tracer::start($exporter, [
-            'skipReporting' => true
-        ]);
 
-        $server->start();
+        $tracer = new RequestHandler(
+            new NullExporter(),
+            new AlwaysSampleSampler(),
+            new HttpHeaderPropagator(),
+            ['skipReporting' => true]
+        );
 
-        $response = $this->client->get($server->getUrl());
-        $this->assertEquals(200, $response->getStatusCode());
+        $this->client->getEmitter()->attach(new EventSubscriber($tracer->tracer()));
 
+        $server->start();
+        $response = $this->client->get($server->getUrl());
         $server->stop();
-
         $tracer->onExit();
+        $this->assertEquals(200, $response->getStatusCode());
 
         $spans = $tracer->tracer()->spans();
-        $this->assertCount(2, $spans);
 
+        $this->assertCount(2, $spans);
         $curlSpan = $spans[1];
-        $this->assertEquals('GuzzleHttp::request', $curlSpan->name());
-        $this->assertEquals('GET', $curlSpan->attributes()['method']);
-        $this->assertEquals($server->getUrl(), $curlSpan->attributes()['uri']);
+        $this->assertEquals('Guzzle: localhost', $curlSpan->name());
+        $this->assertEquals('GET', $curlSpan->attributes()['http.method']);
+        $this->assertEquals($server->getUrl(), $curlSpan->attributes()['http.uri']);
     }
 
-    /**
-     * @runInSeparateProcess
-     */
     public function testPersistsTraceContext()
     {
         $server = HttpTestServer::create(
@@ -97,29 +94,32 @@ function (RequestInterface $request, ResponseInterface &$response) {
         );
 
         $traceContextHeader = '1603c1cde5c74f23bcf1682eb822fcf7/1150672535;o=1';
-        $exporter = new NullExporter();
-        $tracer = Tracer::start($exporter, [
-            'skipReporting' => true,
-            'headers' => [
-                'X-Cloud-Trace-Context' => $traceContextHeader
+        $tracer = new RequestHandler(
+            new NullExporter(),
+            new AlwaysSampleSampler(),
+            new HttpHeaderPropagator(),
+            [
+                'skipReporting' => true,
+                'headers' => [
+                    'X-Cloud-Trace-Context' => $traceContextHeader,
+                ],
             ]
-        ]);
+        );
 
-        $server->start();
+        $this->client->getEmitter()->attach(new EventSubscriber($tracer->tracer()));
 
+        $server->start();
         $response = $this->client->get($server->getUrl());
-        $this->assertEquals(200, $response->getStatusCode());
-
         $server->stop();
-
         $tracer->onExit();
+        $this->assertEquals(200, $response->getStatusCode());
 
         $spans = $tracer->tracer()->spans();
-        $this->assertCount(2, $spans);
 
+        $this->assertCount(2, $spans);
         $curlSpan = $spans[1];
-        $this->assertEquals('GuzzleHttp::request', $curlSpan->name());
-        $this->assertEquals('GET', $curlSpan->attributes()['method']);
-        $this->assertEquals($server->getUrl(), $curlSpan->attributes()['uri']);
+        $this->assertEquals('Guzzle: localhost', $curlSpan->name());
+        $this->assertEquals('GET', $curlSpan->attributes()['http.method']);
+        $this->assertEquals($server->getUrl(), $curlSpan->attributes()['http.uri']);
     }
 }