guzzle auto-instrumentation (#226)

* guzzle auto-instrumentation
* apply review feedback
* update semconv
* adding guzzle to ci and gitsplit
* update readme

.gitattributes

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+* text=auto
+
+*.md diff=markdown
+*.php diff=php
+
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.phan export-ignore
+/.php-cs-fixer.php export-ignore
+/phpstan.neon.dist export-ignore
+/phpunit.xml.dist export-ignore
+/psalm.xml.dist export-ignore
+/tests export-ignore

.gitignore

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+/vendor/

.php-cs-fixer.php

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+<?php
+$finder = PhpCsFixer\Finder::create()
+    ->exclude('vendor')
+    ->exclude('tests/Unit81') //contains php8.1 syntax
+    ->exclude('var/cache')
+    ->exclude('tests/coverage')
+    ->in(__DIR__);
+
+$config = new PhpCsFixer\Config();
+return $config->setRules([
+    'concat_space' => ['spacing' => 'one'],
+    'declare_equal_normalize' => ['space' => 'none'],
+    'is_null' => true,
+    'modernize_types_casting' => true,
+    'ordered_imports' => true,
+    'php_unit_construct' => true,
+    'single_line_comment_style' => true,
+    'yoda_style' => false,
+    '@PSR2' => true,
+    'array_syntax' => ['syntax' => 'short'],
+    'blank_line_after_opening_tag' => true,
+    'blank_line_before_statement' => true,
+    'cast_spaces' => true,
+    'declare_strict_types' => true,
+    'type_declaration_spaces' => true,
+    'include' => true,
+    'lowercase_cast' => true,
+    'new_with_parentheses' => true,
+    'no_extra_blank_lines' => true,
+    'no_leading_import_slash' => true,
+    'echo_tag_syntax' => true,
+    'no_unused_imports' => true,
+    'no_useless_else' => true,
+    'no_useless_return' => true,
+    'phpdoc_order' => true,
+    'phpdoc_scalar' => true,
+    'phpdoc_types' => true,
+    'short_scalar_cast' => true,
+    'blank_lines_before_namespace' => true,
+    'single_quote' => true,
+    'trailing_comma_in_multiline' => true,
+    ])
+    ->setRiskyAllowed(true)
+    ->setFinder($finder);
+

README.md

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+[![Releases](https://img.shields.io/badge/releases-purple)](https://github.com/opentelemetry-php/contrib-auto-guzzle/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/Instrumentation/Guzzle)
+[![Mirror](https://img.shields.io/badge/mirror-opentelemetry--php--contrib-blue)](https://github.com/opentelemetry-php/contrib-auto-guzzle)
+[![Latest Version](http://poser.pugx.org/open-telemetry/opentelemetry-auto-guzzle/v/unstable)](https://packagist.org/packages/open-telemetry/opentelemetry-auto-guzzle/)
+[![Stable](http://poser.pugx.org/open-telemetry/opentelemetry-auto-guzzle/v/stable)](https://packagist.org/packages/open-telemetry/opentelemetry-auto-guzzle/)
+
+This is a read-only subtree split of https://github.com/open-telemetry/opentelemetry-php-contrib.
+
+# OpenTelemetry Guzzle auto-instrumentation
+Please read https://opentelemetry.io/docs/instrumentation/php/automatic/ for instructions on how to
+install and configure the extension and SDK.
+
+## Overview
+Auto-instrumentation hooks are registered via composer.
+
+* create spans automatically for each Guzzle request that is sent (sync or async)
+* add a `traceparent` header to the request to facilitate distributed tracing
+
+## Configuration
+
+The extension can be disabled via [runtime configuration](https://opentelemetry.io/docs/instrumentation/php/sdk/#configuration):
+
+```shell
+OTEL_PHP_DISABLED_INSTRUMENTATIONS=guzzle
+```

_register.php

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+<?php
+
+declare(strict_types=1);
+
+use OpenTelemetry\Contrib\Instrumentation\Guzzle\GuzzleInstrumentation;
+use OpenTelemetry\SDK\Sdk;
+
+if (class_exists(Sdk::class) && Sdk::isInstrumentationDisabled(GuzzleInstrumentation::NAME) === true) {
+    return;
+}
+
+if (extension_loaded('opentelemetry') === false) {
+    trigger_error('The opentelemetry extension must be loaded in order to autoload the OpenTelemetry Guzzle auto-instrumentation', E_USER_WARNING);
+
+    return;
+}
+
+GuzzleInstrumentation::register();

composer.json

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+{
+  "name": "open-telemetry/opentelemetry-auto-guzzle",
+  "description": "OpenTelemetry auto-instrumentation for Guzzle.",
+  "keywords": ["opentelemetry", "otel", "open-telemetry", "tracing", "guzzle", "instrumentation"],
+  "type": "library",
+  "homepage": "https://opentelemetry.io/docs/php",
+  "readme": "./README.md",
+  "license": "Apache-2.0",
+  "minimum-stability": "dev",
+  "prefer-stable": true,
+  "require": {
+    "php": "^8.0",
+    "ext-opentelemetry": "*",
+    "open-telemetry/api": "^1.0",
+    "open-telemetry/sem-conv": "^1.23",
+    "guzzlehttp/guzzle": "^7"
+  },
+  "require-dev": {
+    "friendsofphp/php-cs-fixer": "^3",
+    "guzzlehttp/promises": "^2",
+    "nyholm/psr7": "*",
+    "phan/phan": "^5.0",
+    "phpstan/phpstan-mockery": "^1.1.0",
+    "phpstan/phpstan": "^1.1",
+    "phpstan/phpstan-phpunit": "^1.0",
+    "psalm/plugin-phpunit": "^0.16",
+    "open-telemetry/sdk": "^1.0",
+    "phpunit/phpunit": "^9.5",
+    "vimeo/psalm": "^4.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "OpenTelemetry\\Contrib\\Instrumentation\\Guzzle\\": "src/"
+    },
+    "files": [
+      "_register.php"
+    ]
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "OpenTelemetry\\Tests\\Instrumentation\\Guzzle\\": "tests/"
+    }
+  },
+  "config": {
+    "allow-plugins": {
+      "php-http/discovery": false
+    }
+  }
+}

phpstan.neon.dist

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+includes:
+    - vendor/phpstan/phpstan-phpunit/extension.neon
+
+parameters:
+    tmpDir: var/cache/phpstan
+    level: 5
+    paths:
+        - src
+        - tests
+    excludePaths:
+        analyseAndScan:
+            - tests/Unit

phpunit.xml.dist

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+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.5/phpunit.xsd"
+    backupGlobals="false"
+    backupStaticAttributes="false"
+    cacheResult="false"
+    colors="false"
+    convertErrorsToExceptions="true"
+    convertNoticesToExceptions="true"
+    convertWarningsToExceptions="true"
+    forceCoversAnnotation="false"
+    processIsolation="false"
+    stopOnError="false"
+    stopOnFailure="false"
+    stopOnIncomplete="false"
+    stopOnSkipped="false"
+    stopOnRisky="false"
+    timeoutForSmallTests="1"
+    timeoutForMediumTests="10"
+    timeoutForLargeTests="60"
+    verbose="true">
+
+    <coverage processUncoveredFiles="true" disableCodeCoverageIgnore="false">
+        <include>
+            <directory>src</directory>
+        </include>
+    </coverage>
+
+    <php>
+        <ini name="date.timezone" value="UTC" />
+        <ini name="display_errors" value="On" />
+        <ini name="display_startup_errors" value="On" />
+        <ini name="error_reporting" value="E_ALL" />
+    </php>
+
+    <testsuites>
+        <testsuite name="unit">
+            <directory>tests/Unit</directory>
+        </testsuite>
+        <testsuite name="integration">
+            <directory>tests/Integration</directory>
+        </testsuite>
+    </testsuites>
+
+</phpunit>

psalm.xml.dist

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+<?xml version="1.0"?>
+<psalm
+    errorLevel="3"
+    cacheDirectory="var/cache/psalm"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="https://getpsalm.org/schema/config"
+    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd">
+    <projectFiles>
+        <directory name="src"/>
+        <directory name="tests"/>
+    </projectFiles>
+    <plugins>
+        <pluginClass class="Psalm\PhpUnitPlugin\Plugin"/>
+    </plugins>
+</psalm>

src/GuzzleInstrumentation.php

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+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Instrumentation\Guzzle;
+
+use function get_cfg_var;
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Promise\PromiseInterface;
+use OpenTelemetry\API\Globals;
+use OpenTelemetry\API\Instrumentation\CachedInstrumentation;
+use OpenTelemetry\API\Trace\Span;
+use OpenTelemetry\API\Trace\SpanKind;
+use OpenTelemetry\API\Trace\StatusCode;
+use OpenTelemetry\Context\Context;
+use function OpenTelemetry\Instrumentation\hook;
+use OpenTelemetry\SemConv\TraceAttributes;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+use function sprintf;
+use function strtolower;
+use Throwable;
+
+class GuzzleInstrumentation
+{
+    /** @psalm-suppress ArgumentTypeCoercion */
+    public const NAME = 'guzzle';
+
+    public static function register(): void
+    {
+        $instrumentation = new CachedInstrumentation('io.opentelemetry.contrib.php.guzzle', schemaUrl: TraceAttributes::SCHEMA_URL);
+
+        hook(
+            ClientInterface::class,
+            'transfer',
+            pre: static function (ClientInterface $client, array $params, string $class, string $function, ?string $filename, ?int $lineno) use ($instrumentation): array {
+                $request = $params[0];
+                assert($request instanceof RequestInterface);
+
+                $propagator = Globals::propagator();
+                $parentContext = Context::getCurrent();
+
+                /** @psalm-suppress ArgumentTypeCoercion */
+                $spanBuilder = $instrumentation
+                    ->tracer()
+                    ->spanBuilder(sprintf('%s', $request->getMethod()))
+                    ->setParent($parentContext)
+                    ->setSpanKind(SpanKind::KIND_CLIENT)
+                    ->setAttribute(TraceAttributes::URL_FULL, (string) $request->getUri())
+                    ->setAttribute(TraceAttributes::HTTP_REQUEST_METHOD, $request->getMethod())
+                    ->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $request->getProtocolVersion())
+                    ->setAttribute(TraceAttributes::USER_AGENT_ORIGINAL, $request->getHeaderLine('User-Agent'))
+                    ->setAttribute(TraceAttributes::HTTP_REQUEST_BODY_SIZE, $request->getHeaderLine('Content-Length'))
+                    ->setAttribute(TraceAttributes::SERVER_ADDRESS, $request->getUri()->getHost())
+                    ->setAttribute(TraceAttributes::SERVER_PORT, $request->getUri()->getPort())
+                    ->setAttribute(TraceAttributes::URL_PATH, $request->getUri()->getPath())
+                    ->setAttribute(TraceAttributes::CODE_FUNCTION, $function)
+                    ->setAttribute(TraceAttributes::CODE_NAMESPACE, $class)
+                    ->setAttribute(TraceAttributes::CODE_FILEPATH, $filename)
+                    ->setAttribute(TraceAttributes::CODE_LINENO, $lineno)
+                ;
+
+                foreach ($propagator->fields() as $field) {
+                    $request = $request->withoutHeader($field);
+                }
+                foreach ((array) (get_cfg_var('otel.instrumentation.http.request_headers') ?: []) as $header) {
+                    if ($request->hasHeader($header)) {
+                        $spanBuilder->setAttribute(
+                            sprintf('http.request.header.%s', strtolower($header)),
+                            $request->getHeader($header)
+                        );
+                    }
+                }
+
+                $span = $spanBuilder->startSpan();
+                $context = $span->storeInContext($parentContext);
+                $propagator->inject($request, HeadersPropagator::instance(), $context);
+
+                Context::storage()->attach($context);
+
+                return [$request];
+            },
+            post: static function (ClientInterface $client, array $params, PromiseInterface $promise, ?Throwable $exception): void {
+                $scope = Context::storage()->scope();
+                $scope?->detach();
+
+                if (!$scope || $scope->context() === Context::getCurrent()) {
+                    return;
+                }
+
+                $span = Span::fromContext($scope->context());
+                if ($exception) {
+                    $span->recordException($exception, [TraceAttributes::EXCEPTION_ESCAPED => true]);
+                    $span->setStatus(StatusCode::STATUS_ERROR, $exception->getMessage());
+                    $span->end();
+                }
+
+                $promise->then(
+                    onFulfilled: function (ResponseInterface $response) use ($span) {
+                        $span->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $response->getStatusCode());
+                        $span->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $response->getProtocolVersion());
+                        $span->setAttribute(TraceAttributes::HTTP_RESPONSE_BODY_SIZE, $response->getHeaderLine('Content-Length'));
+                        if ($response->getStatusCode() >= 400 && $response->getStatusCode() < 600) {
+                            $span->setStatus(StatusCode::STATUS_ERROR);
+                        }
+                        $span->end();
+
+                        return $response;
+                    },
+                    onRejected: function (\Throwable $t) use ($span) {
+                        $span->recordException($t, [TraceAttributes::EXCEPTION_ESCAPED => true]);
+                        $span->setStatus(StatusCode::STATUS_ERROR, $t->getMessage());
+                        $span->end();
+
+                        throw $t;
+                    }
+                );
+            }
+        );
+    }
+}

src/HeadersPropagator.php

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+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Instrumentation\Guzzle;
+
+use function assert;
+use OpenTelemetry\Context\Propagation\PropagationSetterInterface;
+use Psr\Http\Message\RequestInterface;
+
+/**
+ * @internal
+ */
+class HeadersPropagator implements PropagationSetterInterface
+{
+    public static function instance(): self
+    {
+        static $instance;
+
+        return $instance ??= new self();
+    }
+
+    public function set(&$carrier, string $key, string $value): void
+    {
+        assert($carrier instanceof RequestInterface);
+
+        $carrier = $carrier->withAddedHeader($key, $value);
+    }
+}