Add baggage propagation in instana

src/Propagation/Instana/README.md

@@ -1,6 +1,15 @@
-OpenTelemetry Instana Propagator
+[![Releases](https://img.shields.io/badge/releases-purple)](https://github.com/opentelemetry-php/contrib-propagator-instana/releases)
+[![Issues](https://img.shields.io/badge/issues-pink)](https://github.com/open-telemetry/opentelemetry-php/issues)
+[![Source](https://img.shields.io/badge/source-contrib-green)](https://github.com/open-telemetry/opentelemetry-php-contrib/tree/main/src/Propagation/Instana)
+[![Mirror](https://img.shields.io/badge/mirror-opentelemetry--php--contrib-blue)](https://github.com/opentelemetry-php/contrib-propagator-instana)
+[![Latest Version](http://poser.pugx.org/open-telemetry/opentelemetry-propagation-instana/v/unstable)](https://packagist.org/packages/open-telemetry/opentelemetry-propagation-instana/)
+[![Stable](http://poser.pugx.org/open-telemetry/opentelemetry-propagation-instana/v/stable)](https://packagist.org/packages/open-telemetry/opentelemetry-propagation-instana/)
 
-The OpenTelemetry Propagator for Instana provides HTTP header propagation for systems that are using IBM Observability by Instana.
+This is a read-only subtree split of https://github.com/open-telemetry/opentelemetry-php-contrib.
+
+# OpenTelemetry Instana Propagator
+
+The OpenTelemetry Propagator for Instana provides HTTP header propagation and Baggage propagation for systems that are using IBM Observability by Instana.
 This propagator translates the Instana trace correlation headers (`X-INSTANA-T/X-INSTANA-S/X-INSTANA-L`) into the OpenTelemetry `SpanContext`, and vice versa.
 It does not handle `TraceState`.
 
@@ -14,7 +23,7 @@ composer require open-telemetry/opentelemetry-propagation-instana
 ## Usage
 
 ```
-$propagator = InstanaMultiPropagator::getInstance();
+$propagator = InstanaPropagator::getInstance();
 ```
 
 Both of the above have extract and inject methods available to extract and inject respectively into the header.

src/Propagation/Instana/_register.php

@@ -1,13 +1,15 @@
 <?php
 
 declare(strict_types=1);
-use OpenTelemetry\Contrib\Propagation\Instana\InstanaMultiPropagator;
+
+use OpenTelemetry\Contrib\Propagation\Instana\InstanaPropagator;
 use OpenTelemetry\SDK\Registry;
 
 if (!class_exists(Registry::class)) {
     return;
 }
+
 Registry::registerTextMapPropagator(
     'instana',
-    InstanaMultiPropagator::getInstance()
+    InstanaPropagator::getInstance()
 );

src/Propagation/Instana/src/InstanaContextPropagator.php

@@ -0,0 +1,172 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Propagation\Instana;
+
+use OpenTelemetry\API\Trace\NonRecordingSpan;
+use OpenTelemetry\API\Trace\Span;
+use OpenTelemetry\API\Trace\SpanContext;
+use OpenTelemetry\API\Trace\SpanContextInterface;
+use OpenTelemetry\API\Trace\TraceFlags;
+use OpenTelemetry\Context\Context;
+use OpenTelemetry\Context\ContextInterface;
+use OpenTelemetry\Context\Propagation\ArrayAccessGetterSetter;
+use OpenTelemetry\Context\Propagation\PropagationGetterInterface;
+use OpenTelemetry\Context\Propagation\PropagationSetterInterface;
+use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
+
+/**
+ * InstanaPropagator is a propagator that supports the specification for multiple
+ * "instana" http headers used for trace context propagation across service
+ * boundaries.
+ */
+final class InstanaContextPropagator implements TextMapPropagatorInterface
+{
+    /**
+     * The  X-INSTANA-T header is required and is encoded as 32 lower-hex characters.
+     * For example, a 128-bit TraceId header might look like: X-Instana-T: 463ac35c9f6413ad48485a3953bb6124 .
+     *
+     */
+    private const INSTANA_TRACE_ID_HEADER = 'X-INSTANA-T';
+
+    /**
+     * The X-Instana-S header must be present on a child span and absent on the root span.
+     * It is encoded as 16 lower-hex characters.
+     * For example, a ParentSpanId header might look like: X-Instana-S: 0020000000000001
+     *
+     */
+    private const INSTANA_SPAN_ID_HEADER = 'X-INSTANA-S';
+
+    /**
+     * An accept sampling decision is encoded as X-INSTANA-L: 1 and a deny as X-INSTANA-L: 0.
+     * Absent means defer the decision to the receiver of this header.
+     * For example, a Sampled header might look like: X-Instana-L: 1
+     *
+     */
+    private const INSTANA_LEVEL_HEADER = 'X-INSTANA-L';
+
+    private const IS_SAMPLED = '1';
+    private const VALID_SAMPLED = [self::IS_SAMPLED, 'true'];
+    private const IS_NOT_SAMPLED = '0';
+    private const VALID_NON_SAMPLED = [self::IS_NOT_SAMPLED, 'false'];
+
+    private const FIELDS = [
+        self::INSTANA_TRACE_ID_HEADER,
+        self::INSTANA_SPAN_ID_HEADER,
+        self::INSTANA_LEVEL_HEADER,
+    ];
+
+    private static ?self $instance = null;
+
+    public static function getInstance(): self
+    {
+        if (null === self::$instance) {
+            self::$instance = new self();
+        }
+
+        return self::$instance;
+    }
+
+    /**
+     * @suppress PhanUndeclaredClassAttribute
+     */
+    #[\Override]
+    public function fields(): array
+    {
+        return self::FIELDS;
+    }
+
+    /**
+     * @suppress PhanUndeclaredClassAttribute
+     */
+    #[\Override]
+    public function inject(&$carrier, ?PropagationSetterInterface $setter = null, ?ContextInterface $context = null): void
+    {
+        $setter ??= ArrayAccessGetterSetter::getInstance();
+        $context ??= Context::getCurrent();
+        $spanContext = Span::fromContext($context)->getContext();
+
+        if (!$spanContext->isValid()) {
+            return;
+        }
+
+        // Inject multiple Instana headers
+        $setter->set($carrier, self::INSTANA_TRACE_ID_HEADER, $spanContext->getTraceId());
+        $setter->set($carrier, self::INSTANA_SPAN_ID_HEADER, $spanContext->getSpanId());
+        $setter->set($carrier, self::INSTANA_LEVEL_HEADER, $spanContext->isSampled() ? self::IS_SAMPLED : self::IS_NOT_SAMPLED);
+    }
+
+    /**
+     * @suppress PhanUndeclaredClassAttribute
+     */
+    #[\Override]
+    public function extract($carrier, ?PropagationGetterInterface $getter = null, ?ContextInterface $context = null): ContextInterface
+    {
+        $getter ??= ArrayAccessGetterSetter::getInstance();
+        $context ??= Context::getCurrent();
+
+        $traceId = self::readHeader($carrier, $getter, self::INSTANA_TRACE_ID_HEADER);
+        $spanId = self::readHeader($carrier, $getter, self::INSTANA_SPAN_ID_HEADER);
+        $level = self::getSampledValue($carrier, $getter);
+
+        $spanContext = self::extractImpl($carrier, $getter);
+
+        if (($traceId === '' &&  $spanId === '') && $level !== null) {
+            return (new NonRecordingSpan($spanContext))
+                ->storeInContext($context);
+        } elseif (!$spanContext->isValid()) {
+            return $context;
+        }
+
+        return $context->withContextValue(Span::wrap($spanContext));
+    }
+
+    private static function readHeader($carrier, PropagationGetterInterface $getter, string $key): string
+    {
+        $header = $getter->get($carrier, $key) ?: '';
+
+        // Return the header or an empty string if not found
+        return $header;
+    }
+
+    private static function getSampledValue($carrier, PropagationGetterInterface $getter): ?int
+    {
+        $value = $getter->get($carrier, self::INSTANA_LEVEL_HEADER);
+
+        if ($value === null) {
+            return null;
+        }
+
+        if (in_array(strtolower($value), self::VALID_SAMPLED)) {
+            return (int) self::IS_SAMPLED;
+        }
+
+        if (in_array(strtolower($value), self::VALID_NON_SAMPLED)) {
+            return (int) self::IS_NOT_SAMPLED;
+        }
+
+        return null;
+    }
+
+    private static function extractImpl($carrier, PropagationGetterInterface $getter): SpanContextInterface
+    {
+        $traceId = self::readHeader($carrier, $getter, self::INSTANA_TRACE_ID_HEADER);
+        $spanId = self::readHeader($carrier, $getter, self::INSTANA_SPAN_ID_HEADER);
+        $level = self::getSampledValue($carrier, $getter);
+
+        if ($traceId && strlen($traceId) < 32) {
+            $traceId = str_pad($traceId, 32, '0', STR_PAD_LEFT);
+        }
+
+        if ($spanId && strlen($spanId) < 16) {
+            $spanId = str_pad($spanId, 16, '0', STR_PAD_LEFT);
+        }
+
+        return SpanContext::createFromRemoteParent(
+            $traceId,
+            $spanId,
+            $level ? TraceFlags::SAMPLED : TraceFlags::DEFAULT
+        );
+    }
+}

src/Propagation/Instana/src/InstanaPropagator.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Propagation\Instana;
+
+use OpenTelemetry\API\Baggage\Propagation\BaggagePropagator;
+use OpenTelemetry\Context\Context;
+use OpenTelemetry\Context\ContextInterface;
+use OpenTelemetry\Context\Propagation\PropagationGetterInterface;
+use OpenTelemetry\Context\Propagation\PropagationSetterInterface;
+use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
+
+class InstanaPropagator implements TextMapPropagatorInterface
+{
+    /** @var TextMapPropagatorInterface[] */
+    private array $propagators;
+
+    private static ?self $instance = null;
+
+    public function __construct(array $propagators)
+    {
+        $this->propagators = $propagators;
+    }
+
+    public static function getInstance(): self
+    {
+        if (null === self::$instance) {
+            // Create propagator instances
+            $instanaPropagator =  InstanaContextPropagator::getInstance();
+            $baggagePropagator = new BaggagePropagator();
+            self::$instance = new self([$instanaPropagator, $baggagePropagator]);
+        }
+
+        return self::$instance;
+    }
+
+    /**
+    * @suppress PhanUndeclaredClassAttribute
+    */
+    #[\Override]
+    public function fields(): array
+    {
+        $fields = [];
+        foreach ($this->propagators as $propagator) {
+            $fields = array_merge($fields, $propagator->fields());
+        }
+
+        return array_values(array_unique($fields));
+    }
+
+    /**
+     * @suppress PhanUndeclaredClassAttribute
+     */
+    #[\Override]
+    public function inject(&$carrier, ?PropagationSetterInterface $setter = null, ?ContextInterface $context = null): void
+    {
+        foreach ($this->propagators as $propagator) {
+            $propagator->inject($carrier, $setter, $context);
+        }
+    }
+
+    /**
+     * @suppress PhanUndeclaredClassAttribute
+     */
+    #[\Override]
+    public function extract($carrier, ?PropagationGetterInterface $getter = null, ?ContextInterface $context = null): ContextInterface
+    {
+        $context ??= Context::getCurrent();
+        foreach ($this->propagators as $propagator) {
+            $context = $propagator->extract($carrier, $getter, $context);
+        }
+
+        return $context;
+    }
+}