Add B3 multiple headers propagation

src/Trace/Integrations/Guzzle/EventSubscriber.php

@@ -88,7 +88,7 @@ public function onBefore(BeforeEvent $event)
         $request = $event->getRequest();
         $context = Tracer::spanContext();
         if ($context->enabled()) {
-            $request->setHeader($this->propagator->key(), $this->propagator->formatter()->serialize($context));
+            $request->setHeaders($this->propagator->inject($context, []));
         }
         $span = Tracer::startSpan([
             'name' => 'GuzzleHttp::request',

src/Trace/Integrations/Guzzle/Middleware.php

@@ -70,10 +70,11 @@ public function __invoke(callable $handler)
         return function (RequestInterface $request, $options) use ($handler) {
             $context = Tracer::spanContext();
             if ($context->enabled()) {
-                $request = $request->withHeader(
-                    $this->propagator->key(),
-                    $this->propagator->formatter()->serialize($context)
-                );
+                $headers = $this->propagator->inject($context, []) ;
+
+                foreach ($headers as $headerName => $headerValue) {
+                    $request = $request->withHeader($headerName, $headerValue);
+                }
             }
             return Tracer::inSpan([
                 'name' => 'GuzzleHttp::request',

src/Trace/Propagator/B3HeadersPropagator.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace OpenCensus\Trace\Propagator;
+
+use OpenCensus\Trace\SpanContext;
+
+/**
+ * @see https://github.com/openzipkin/b3-propagation
+ */
+class B3HeadersPropagator implements PropagatorInterface
+{
+    private const X_B3_TRACE_ID = 'X-B3-TraceId';
+    private const X_B3_SPAN_ID = 'X-B3-SpanId';
+    private const X_B3_SAMPLED = 'X-B3-Sampled';
+    private const X_B3_FLAGS = 'X-B3-Flags';
+
+    /**
+     * Extract the SpanContext from some container
+     *
+     * @param mixed $container
+     * @return SpanContext
+     */
+    public function extract($container)
+    {
+        $traceId = $container[self::X_B3_TRACE_ID] ?? null;
+        $spanId = $container[self::X_B3_SPAN_ID] ?? null;
+        $sampled = $container[self::X_B3_SAMPLED] ?? null;
+        $flags = $container[self::X_B3_FLAGS] ?? null;
+
+        $enabled = null;
+
+        if ($sampled !== null) {
+            $enabled = $sampled === '1';
+        }
+
+        if ($flags === '1') {
+            $enabled = true;
+        }
+
+        return new SpanContext($traceId, $spanId, $enabled, true);
+    }
+
+    /**
+     * Inject the SpanContext back into the response
+     *
+     * @param SpanContext $context
+     * @param mixed $container
+     * @return array
+     */
+    public function inject(SpanContext $context, $container)
+    {
+        return [
+            self::X_B3_TRACE_ID => $context->traceId(),
+            self::X_B3_SPAN_ID => $context->spanId(),
+            self::X_B3_SAMPLED => $context->enabled() ? 1 : 0,
+        ] + $container;
+    }
+}

src/Trace/Propagator/FormatterInterface.php

@@ -27,7 +27,7 @@ interface FormatterInterface
     /**
      * Generate a SpanContext object from the Trace Context header
      *
-     * @param string $header
+     * @param string[] $header
      * @return SpanContext
      */
     public function deserialize($header);

src/Trace/Propagator/GrpcMetadataPropagator.php

@@ -78,24 +78,4 @@ public function inject(SpanContext $context, $metadata)
         $metadata[$this->key] = $this->formatter->serialize($context);
         return $metadata;
     }
-
-    /**
-     * Fetch the formatter for propagating the SpanContext
-     *
-     * @return FormatterInterface
-     */
-    public function formatter()
-    {
-        return $this->formatter;
-    }
-
-    /**
-     * Return the key used to propagate the SpanContext
-     *
-     * @return string
-     */
-    public function key()
-    {
-        return $this->key;
-    }
 }

src/Trace/Propagator/HttpHeaderPropagator.php

@@ -25,7 +25,7 @@
  */
 class HttpHeaderPropagator implements PropagatorInterface
 {
-    const DEFAULT_HEADER = 'HTTP_X_CLOUD_TRACE_CONTEXT';
+    const DEFAULT_HEADER = 'X-Cloud-Trace-Context';
 
     /**
      * @var FormatterInterface
@@ -44,7 +44,7 @@ class HttpHeaderPropagator implements PropagatorInterface
      *        deserialize SpanContext. **Defaults to** a new
      *        CloudTraceFormatter.
      * @param string $key [optional] The header key to store/retrieve the
-     *        encoded SpanContext. **Defaults to** `HTTP_X_CLOUD_TRACE_CONTEXT`
+     *        encoded SpanContext. **Defaults to** `X-Cloud-Trace-Context`
      */
     public function __construct(FormatterInterface $formatter = null, $header = null)
     {
@@ -75,33 +75,11 @@ public function extract($headers)
      */
     public function inject(SpanContext $context, $container)
     {
-        $header = $this->key();
+        $header = $this->header;
         $value = $this->formatter->serialize($context);
-        if (!headers_sent()) {
-            header("$header: $value");
-        }
-        return [
-            $header => $value
-        ];
-    }
 
-    /**
-     * Returns the current formatter
-     *
-     * @return FormatterInterface
-     */
-    public function formatter()
-    {
-        return $this->formatter;
-    }
+        $container[$header] = $value;
 
-    /**
-     * Return the key used to propagate the SpanContext
-     *
-     * @return string
-     */
-    public function key()
-    {
-        return str_replace('_', '-', preg_replace('/^HTTP_/', '', $this->header));
+        return $container;
     }
 }

src/Trace/Propagator/PropagatorInterface.php

@@ -42,18 +42,4 @@ public function extract($container);
      * @return array
      */
     public function inject(SpanContext $context, $container);
-
-    /**
-     * Fetch the formatter for propagating the SpanContext
-     *
-     * @return FormatterInterface
-     */
-    public function formatter();
-
-    /**
-     * Return the key used to propagate the SpanContext
-     *
-     * @return string
-     */
-    public function key();
 }

src/Trace/SpanContext.php

@@ -52,6 +52,12 @@ class SpanContext
      */
     private $enabled;
 
+
+    /**
+     * @var bool Whether or not this context was detected from a request header.
+     */
+    private $fromHeader;
+
     /**
      * Creates a new SpanContext instance
      *

tests/integration/guzzle5/tests/Guzzle5Test.php

@@ -95,7 +95,7 @@ function (RequestInterface $request, ResponseInterface &$response) {
         $tracer = Tracer::start($exporter->reveal(), [
             'skipReporting' => true,
             'headers' => [
-                'HTTP_X_CLOUD_TRACE_CONTEXT' => $traceContextHeader
+                'X-Cloud-Trace-Context' => $traceContextHeader
             ]
         ]);
 

tests/integration/guzzle6/tests/Guzzle6Test.php

@@ -95,7 +95,7 @@ function (RequestInterface $request, ResponseInterface &$response) {
         $tracer = Tracer::start($exporter->reveal(), [
             'skipReporting' => true,
             'headers' => [
-                'HTTP_X_CLOUD_TRACE_CONTEXT' => $traceContextHeader
+                'X-Cloud-Trace-Context' => $traceContextHeader
             ]
         ]);
 

tests/unit/Trace/Integrations/Guzzle/EventSubscriberTest.php

@@ -72,8 +72,8 @@ public function testAddsSpanContextHeader()
 
         $request = $history->getLastRequest();
         $headers = $request->getHeaders();
-        $this->assertArrayHasKey('X-CLOUD-TRACE-CONTEXT', $headers);
-        $this->assertRegExp('/[0-9a-f]+\/4660;o=1/', $headers['X-CLOUD-TRACE-CONTEXT'][0]);
+        $this->assertArrayHasKey('X-Cloud-Trace-Context', $headers);
+        $this->assertRegExp('/[0-9a-f]+\/4660;o=1/', $headers['X-Cloud-Trace-Context'][0]);
 
         $rt->onExit();
     }

tests/unit/Trace/Integrations/Guzzle/MiddlewareTest.php

@@ -63,7 +63,7 @@ public function testAddsSpanContextHeader()
         $req = $this->prophesize(RequestInterface::class);
         $req->getMethod()->willReturn('GET')->shouldBeCalled();
         $req->getUri()->willReturn('/')->shouldBeCalled();
-        $req->withHeader('X-CLOUD-TRACE-CONTEXT', Argument::that(function ($val) {
+        $req->withHeader('X-Cloud-Trace-Context', Argument::that(function ($val) {
             return preg_match('/[0-9a-f]+\/4660;o=1/', $val);
         }))->willReturn($req->reveal())->shouldBeCalled();
         $request = $req->reveal();

tests/unit/Trace/Propagator/B3HeadersPropagatorTest.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace OpenCensus\Tests\Unit\Trace\Propagator;
+
+use OpenCensus\Trace\Propagator\B3HeadersPropagator;
+use OpenCensus\Trace\Propagator\HttpHeaderPropagator;
+use OpenCensus\Trace\SpanContext;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @group trace
+ */
+class B3HeadersPropagatorTest extends TestCase
+{
+    /**
+     * @dataProvider traceMetadata
+     */
+    public function testExtract($traceId, $spanId, $enabled, $headers)
+    {
+        $propagator = new B3HeadersPropagator();
+        $context = $propagator->extract($headers);
+        $this->assertEquals($traceId, $context->traceId());
+        $this->assertEquals($spanId, $context->spanId());
+        $this->assertEquals($enabled, $context->enabled());
+        $this->assertTrue($context->fromHeader());
+    }
+
+    /**
+     * @dataProvider traceMetadata
+     */
+    public function testInject($traceId, $spanId, $enabled, $headers)
+    {
+        $propagator = new B3HeadersPropagator();
+        $context = new SpanContext($traceId, $spanId, $enabled);
+        $output = $propagator->inject($context, []);
+
+        if (array_key_exists('X-B3-Flags', $headers)) {
+            $headers['X-B3-Sampled'] = $headers['X-B3-Flags'];
+            unset($headers['X-B3-Flags']);
+        }
+
+        $this->assertEquals($headers, $output);
+    }
+
+    public function traceMetadata()
+    {
+        return [
+            [
+                '463ac35c9f6413ad48485a3953bb6124',
+                'a2fb4a1d1a96d312',
+                true,
+                [
+                    'X-B3-TraceId' => '463ac35c9f6413ad48485a3953bb6124',
+                    'X-B3-SpanId' => 'a2fb4a1d1a96d312',
+                    'X-B3-Sampled' => '1',
+                ],
+            ],
+            [
+                '463ac35c9f6413ad48485a3953bb6124',
+                'a2fb4a1d1a96d312',
+                false,
+                [
+                    'X-B3-TraceId' => '463ac35c9f6413ad48485a3953bb6124',
+                    'X-B3-SpanId' => 'a2fb4a1d1a96d312',
+                    'X-B3-Sampled' => '0',
+                ],
+            ],
+            [
+                '463ac35c9f6413ad48485a3953bb6124',
+                'a2fb4a1d1a96d312',
+                true,
+                [
+                    'X-B3-TraceId' => '463ac35c9f6413ad48485a3953bb6124',
+                    'X-B3-SpanId' => 'a2fb4a1d1a96d312',
+                    'X-B3-Flags' => '1',
+                ],
+            ],
+        ];
+    }
+}

tests/unit/Trace/Propagator/HttpHeaderPropagatorTest.php

@@ -33,7 +33,7 @@ class HttpHeaderPropagatorTest extends TestCase
     public function testExtract($traceId, $spanId, $enabled, $header)
     {
         $propagator = new HttpHeaderPropagator();
-        $context = $propagator->extract(['HTTP_X_CLOUD_TRACE_CONTEXT' => $header]);
+        $context = $propagator->extract(['X-Cloud-Trace-Context' => $header]);
         $this->assertEquals($traceId, $context->traceId());
         $this->assertEquals($spanId, $context->spanId());
         $this->assertEquals($enabled, $context->enabled());
@@ -45,8 +45,8 @@ public function testExtract($traceId, $spanId, $enabled, $header)
      */
     public function testExtractCustomKey($traceId, $spanId, $enabled, $header)
     {
-        $propagator = new HttpHeaderPropagator(new CloudTraceFormatter(), 'HTTP_TRACE_CONTEXT');
-        $context = $propagator->extract(['HTTP_TRACE_CONTEXT' => $header]);
+        $propagator = new HttpHeaderPropagator(new CloudTraceFormatter(), 'Trace-Context');
+        $context = $propagator->extract(['Trace-Context' => $header]);
         $this->assertEquals($traceId, $context->traceId());
         $this->assertEquals($spanId, $context->spanId());
         $this->assertEquals($enabled, $context->enabled());
@@ -61,20 +61,20 @@ public function testInject($traceId, $spanId, $enabled, $header)
         $propagator = new HttpHeaderPropagator();
         $context = new SpanContext($traceId, $spanId, $enabled);
         $output = $propagator->inject($context, []);
-        $this->assertArrayHasKey('X-CLOUD-TRACE-CONTEXT', $output);
-        $this->assertEquals($header, $output['X-CLOUD-TRACE-CONTEXT']);
+        $this->assertArrayHasKey('X-Cloud-Trace-Context', $output);
+        $this->assertEquals($header, $output['X-Cloud-Trace-Context']);
     }
 
     /**
      * @dataProvider traceMetadata
      */
     public function testInjectCustomKey($traceId, $spanId, $enabled, $header)
     {
-        $propagator = new HttpHeaderPropagator(new CloudTraceFormatter(), 'HTTP_TRACE_CONTEXT');
+        $propagator = new HttpHeaderPropagator(new CloudTraceFormatter(), 'Trace-Context');
         $context = new SpanContext($traceId, $spanId, $enabled);
         $output = $propagator->inject($context, []);
-        $this->assertArrayHasKey('TRACE-CONTEXT', $output);
-        $this->assertEquals($header, $output['TRACE-CONTEXT']);
+        $this->assertArrayHasKey('Trace-Context', $output);
+        $this->assertEquals($header, $output['Trace-Context']);
     }
 
     /**

tests/unit/Trace/RequestHandlerTest.php

@@ -87,7 +87,7 @@ public function testCanParseParentContext()
             new HttpHeaderPropagator(),
             [
                 'headers' => [
-                    'HTTP_X_CLOUD_TRACE_CONTEXT' => '12345678901234567890123456789012/5555;o=1'
+                    'X-Cloud-Trace-Context' => '12345678901234567890123456789012/5555;o=1'
                 ],
                 'skipReporting' => true
             ]
@@ -106,7 +106,7 @@ public function testForceEnabledContextHeader()
             new HttpHeaderPropagator(),
             [
                 'headers' => [
-                    'HTTP_X_CLOUD_TRACE_CONTEXT' => '12345678901234567890123456789012;o=1'
+                    'X-Cloud-Trace-Context' => '12345678901234567890123456789012;o=1'
                 ],
                 'skipReporting' => true
             ]
@@ -124,7 +124,7 @@ public function testForceDisabledContextHeader()
             new HttpHeaderPropagator(),
             [
                 'headers' => [
-                    'HTTP_X_CLOUD_TRACE_CONTEXT' => '12345678901234567890123456789012;o=0'
+                    'X-Cloud-Trace-Context' => '12345678901234567890123456789012;o=0'
                 ],
                 'skipReporting' => true
             ]