sdk autoloading (#854)

* sdk autoloading
* use instrumentation initializers
* basic sdk + autoloading documentation
* exampler filter from config
* configuration default types

composer.json

@@ -64,7 +64,8 @@
             "src/Context/fiber/initialize_fiber_handler.php",
             "src/API/Trace/functions.php",
             "src/SDK/Common/Dev/Compatibility/_load.php",
-            "src/SDK/Common/Util/functions.php"
+            "src/SDK/Common/Util/functions.php",
+            "src/SDK/_autoload.php"
         ]
     },
     "autoload-dev": {
@@ -96,7 +97,7 @@
         "phpstan/phpstan-phpunit": "^1.0",
         "phpunit/phpunit": "^9.3",
         "psalm/plugin-mockery": "^0.9",
-        "psalm/plugin-phpunit": "^0.16",
+        "psalm/plugin-phpunit": "^0.18",
         "psalm/psalm": "^4.0",
         "qossmic/deptrac-shim": "^0.24",
         "rector/rector": "^0.13.7",

deptrac.yaml

@@ -38,6 +38,10 @@ deptrac:
           collectors:
               -   type: className
                   regex: ^OpenTelemetry\\Contrib\\*
+      -   name: Extension
+          collectors:
+            -   type: className
+                regex: ^OpenTelemetry\\Extension\\*
       -   name: OtelProto
           collectors:
               -   type: className
@@ -110,6 +114,8 @@ deptrac:
           - Thrift
           - JaegerThrift
           - Swoole
+      Extension:
+          - +API
       OtelProto:
           - GoogleProtobuf
           - Grpc

docker-compose.yaml

@@ -8,6 +8,7 @@ services:
     environment:
       XDEBUG_MODE: ${XDEBUG_MODE:-off}
       XDEBUG_CONFIG: ${XDEBUG_CONFIG:-''}
+      PHP_IDE_CONFIG: ${PHP_IDE_CONFIG:-''}
   zipkin:
     image: openzipkin/zipkin-slim
     ports:

examples/autoload_sdk.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+putenv('OTEL_PHP_AUTOLOAD_ENABLED=true');
+putenv('OTEL_TRACES_EXPORTER=otlp');
+putenv('OTEL_EXPORTER_OTLP_PROTOCOL=grpc');
+putenv('OTEL_METRICS_EXPORTER=otlp');
+putenv('OTEL_EXPORTER_OTLP_METRICS_PROTOCOL=grpc');
+putenv('OTEL_EXPORTER_OTLP_ENDPOINT=http://collector:4317');
+putenv('OTEL_PHP_TRACES_PROCESSOR=batch');
+
+// Composer autoloader will execute SDK/_autoload.php which will register global instrumentation from environment configuration
+require dirname(__DIR__) . '/vendor/autoload.php';
+
+$instrumentation = new \OpenTelemetry\API\Common\Instrumentation\CachedInstrumentation('demo');
+
+$instrumentation->tracer()->spanBuilder('root')->startSpan()->end();

rector.php

@@ -2,6 +2,7 @@
 
 declare(strict_types=1);
 
+use Rector\CodeQuality\Rector\Array_\CallableThisArrayToAnonymousFunctionRector;
 use Rector\Config\RectorConfig;
 use Rector\Core\ValueObject\PhpVersion;
 use Rector\Set\ValueObject\SetList;
@@ -17,4 +18,10 @@ return static function (RectorConfig $rectorConfig): void {
         SetList::PHP_74,
         SetList::CODE_QUALITY,
     ]);
+    $rectorConfig->skip([
+        CallableThisArrayToAnonymousFunctionRector::class => [
+            __DIR__ . '/src/SDK/SdkBuilder.php',
+            __DIR__ . '/src/SDK/SdkAutoloader.php',
+        ],
+    ]);
 };

src/Contrib/Otlp/ContentTypes.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Otlp;
+
+interface ContentTypes
+{
+    public const PROTOBUF = 'application/x-protobuf';
+    public const JSON     = 'application/json';
+    public const NDJSON   = 'application/x-ndjson';
+}

src/Contrib/Otlp/MetricExporterFactory.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Otlp;
+
+use OpenTelemetry\API\Common\Signal\Signals;
+use OpenTelemetry\Contrib\Grpc\GrpcTransportFactory;
+use OpenTelemetry\SDK\Common\Configuration\Configuration;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Common\Export\Http\PsrTransportFactory;
+use OpenTelemetry\SDK\Common\Export\TransportInterface;
+use OpenTelemetry\SDK\Metrics\MetricExporterInterface;
+use UnexpectedValueException;
+
+class MetricExporterFactory
+{
+    /**
+     * @psalm-suppress ArgumentTypeCoercion
+     */
+    public function create(): MetricExporterInterface
+    {
+        $protocol = Configuration::has(Variables::OTEL_EXPORTER_OTLP_METRICS_PROTOCOL)
+            ? Configuration::getEnum(Variables::OTEL_EXPORTER_OTLP_METRICS_PROTOCOL)
+            : Configuration::getEnum(Variables::OTEL_EXPORTER_OTLP_PROTOCOL);
+
+        return new MetricExporter($this->buildTransport($protocol));
+    }
+
+    private function buildTransport(string $protocol): TransportInterface
+    {
+        /**
+         * @todo (https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#periodic-exporting-metricreader)
+         * - OTEL_METRIC_EXPORT_INTERVAL
+         * - OTEL_METRIC_EXPORT_TIMEOUT
+         */
+        $endpoint = Configuration::has(Variables::OTEL_EXPORTER_OTLP_METRICS_ENDPOINT)
+            ? Configuration::getString(Variables::OTEL_EXPORTER_OTLP_METRICS_ENDPOINT)
+            : Configuration::getString(Variables::OTEL_EXPORTER_OTLP_ENDPOINT);
+
+        $headers = Configuration::has(Variables::OTEL_EXPORTER_OTLP_METRICS_HEADERS)
+            ? Configuration::getMap(Variables::OTEL_EXPORTER_OTLP_METRICS_HEADERS)
+            : Configuration::getMap(Variables::OTEL_EXPORTER_OTLP_HEADERS);
+        $headers += OtlpUtil::getUserAgentHeader();
+
+        switch ($protocol) {
+            case KnownValues::VALUE_GRPC:
+                return (new GrpcTransportFactory())->create(
+                    $endpoint . OtlpUtil::method(Signals::METRICS),
+                    ContentTypes::PROTOBUF,
+                    $headers,
+                );
+            case KnownValues::VALUE_HTTP_PROTOBUF:
+            case KnownValues::VALUE_HTTP_JSON:
+                return PsrTransportFactory::discover()->create(
+                    $endpoint,
+                    Protocols::contentType($protocol),
+                    $headers,
+                );
+            default:
+                throw new UnexpectedValueException('Unknown otlp protocol: ' . $protocol);
+        }
+    }
+}

src/Contrib/Otlp/Protocols.php

@@ -14,10 +14,10 @@ class Protocols
     public const HTTP_JSON = KnownValues::VALUE_HTTP_JSON;
     public const HTTP_NDJSON = KnownValues::VALUE_HTTP_NDJSON;
     private const PROTOCOLS = [
-        self::GRPC => 'application/x-protobuf',
-        self::HTTP_PROTOBUF => 'application/x-protobuf',
-        self::HTTP_JSON => 'application/json',
-        self::HTTP_NDJSON => 'application/x-ndjson',
+        self::GRPC => ContentTypes::PROTOBUF,
+        self::HTTP_PROTOBUF => ContentTypes::PROTOBUF,
+        self::HTTP_JSON => ContentTypes::JSON,
+        self::HTTP_NDJSON => ContentTypes::NDJSON,
     ];
 
     public static function validate(string $protocol): void

src/Contrib/Zipkin/SpanConverter.php

@@ -182,7 +182,7 @@ class SpanConverter implements SpanConverterInterface
         }
 
         $attributesAsJson = json_encode($event->getAttributes()->toArray());
-        if (($attributesAsJson === false) || ($attributesAsJson === '')) {
+        if (($attributesAsJson === false)) {
             return null;
         }
 

src/SDK/Common/Configuration/Configuration.php

@@ -36,7 +36,7 @@ class Configuration
         );
     }
 
-    public static function getString(string $key, string $default = ''): string
+    public static function getString(string $key, string $default = null): string
     {
         return (string) self::validateVariableValue(
             CompositeResolver::instance()->resolve(
@@ -58,7 +58,7 @@ class Configuration
         );
     }
 
-    public static function getMixed(string $key, string $default = null)
+    public static function getMixed(string $key, $default = null)
     {
         return self::validateVariableValue(
             CompositeResolver::instance()->resolve(
@@ -68,7 +68,7 @@ class Configuration
         );
     }
 
-    public static function getMap(string $key, string $default = null): array
+    public static function getMap(string $key, array $default = null): array
     {
         return MapParser::parse(
             CompositeResolver::instance()->resolve(
@@ -78,7 +78,7 @@ class Configuration
         );
     }
 
-    public static function getList(string $key, string $default = null): array
+    public static function getList(string $key, array $default = null): array
     {
         return ListParser::parse(
             CompositeResolver::instance()->resolve(
@@ -98,7 +98,7 @@ class Configuration
         );
     }
 
-    public static function getFloat(string $key, string $default = null): float
+    public static function getFloat(string $key, float $default = null): float
     {
         return (float) self::validateVariableValue(
             CompositeResolver::instance()->resolve(

src/SDK/Common/Configuration/Defaults.php

@@ -102,4 +102,5 @@ interface Defaults
      */
     public const OTEL_PHP_TRACES_PROCESSOR = 'batch';
     public const OTEL_PHP_DETECTORS = 'all';
+    public const OTEL_PHP_AUTOLOAD_ENABLED = 'false';
 }

src/SDK/Common/Configuration/KnownValues.php

@@ -165,6 +165,7 @@ interface KnownValues
         self::VALUE_NOOP,
         self::VALUE_NONE,
     ];
+    public const OTEL_PHP_AUTOLOAD_ENABLED = self::VALUES_BOOLEAN;
     public const VALUE_DETECTORS_ENVIRONMENT = 'env';
     public const VALUE_DETECTORS_HOST = 'host';
     public const VALUE_DETECTORS_OS = 'os';

src/SDK/Common/Configuration/Variables.php

@@ -120,4 +120,5 @@ interface Variables
      */
     public const OTEL_PHP_TRACES_PROCESSOR = 'OTEL_PHP_TRACES_PROCESSOR';
     public const OTEL_PHP_DETECTORS = 'OTEL_PHP_DETECTORS';
+    public const OTEL_PHP_AUTOLOAD_ENABLED = 'OTEL_PHP_AUTOLOAD_ENABLED';
 }

src/SDK/Metrics/MeterProviderBuilder.php

@@ -8,6 +8,7 @@ use OpenTelemetry\SDK\Common\Attribute\Attributes;
 use OpenTelemetry\SDK\Common\Instrumentation\InstrumentationScopeFactory;
 use OpenTelemetry\SDK\Common\Time\ClockFactory;
 use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\WithSampledTraceExemplarFilter;
+use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilterInterface;
 use OpenTelemetry\SDK\Metrics\StalenessHandler\ImmediateStalenessHandlerFactory;
 use OpenTelemetry\SDK\Metrics\View\CriteriaViewRegistry;
 use OpenTelemetry\SDK\Resource\ResourceInfo;
@@ -18,6 +19,7 @@ class MeterProviderBuilder
     // @var array<MetricReaderInterface>
     private array $metricReaders = [];
     private ?ResourceInfo $resource = null;
+    private ?ExemplarFilterInterface $exemplarFilter = null;
 
     public function registerMetricReader(MetricReaderInterface $reader): self
     {
@@ -33,6 +35,13 @@ class MeterProviderBuilder
         return $this;
     }
 
+    public function setExemplarFilter(ExemplarFilterInterface $exemplarFilter): self
+    {
+        $this->exemplarFilter = $exemplarFilter;
+
+        return $this;
+    }
+
     public function addReader(MetricReaderInterface $reader): self
     {
         $this->metricReaders[] = $reader;
@@ -53,7 +62,7 @@ class MeterProviderBuilder
             new InstrumentationScopeFactory(Attributes::factory()),
             $this->metricReaders,
             new CriteriaViewRegistry(),
-            new WithSampledTraceExemplarFilter(),
+            $this->exemplarFilter ?? new WithSampledTraceExemplarFilter(),
             new ImmediateStalenessHandlerFactory(),
         );
     }

src/SDK/Metrics/MeterProviderFactory.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Metrics;
+
+use OpenTelemetry\SDK\Behavior\LogsMessagesTrait;
+use OpenTelemetry\SDK\Common\Configuration\Configuration;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Common\Time\ClockFactory;
+use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\AllExemplarFilter;
+use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\NoneExemplarFilter;
+use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilter\WithSampledTraceExemplarFilter;
+use OpenTelemetry\SDK\Metrics\Exemplar\ExemplarFilterInterface;
+use OpenTelemetry\SDK\Metrics\MetricExporter\NoopMetricExporter;
+use OpenTelemetry\SDK\Metrics\MetricReader\ExportingReader;
+use OpenTelemetry\SDK\Resource\ResourceInfoFactory;
+use OpenTelemetry\SDK\Sdk;
+
+class MeterProviderFactory
+{
+    use LogsMessagesTrait;
+
+    private const KNOWN_EXPORTER_FACTORIES = [
+        KnownValues::VALUE_OTLP => '\OpenTelemetry\Contrib\Otlp\MetricExporterFactory',
+    ];
+
+    public function create(): MeterProviderInterface
+    {
+        if (Sdk::isDisabled()) {
+            return new NoopMeterProvider();
+        }
+        $exporterName = Configuration::getString(Variables::OTEL_METRICS_EXPORTER);
+        if ($exporterName === KnownValues::VALUE_NONE) {
+            $exporter = new NoopMetricExporter();
+        } elseif (!array_key_exists($exporterName, self::KNOWN_EXPORTER_FACTORIES)) {
+            self::logError('Factory cannot create exporter: ' . $exporterName);
+            $exporter = new NoopMetricExporter();
+        } else {
+            $factoryClass = self::KNOWN_EXPORTER_FACTORIES[$exporterName];
+            $factory = new $factoryClass();
+            $exporter = $factory->create();
+        }
+        $reader = new ExportingReader($exporter, ClockFactory::getDefault());
+        $resource = ResourceInfoFactory::defaultResource();
+        $exemplarFilter = $this->createExemplarFilter(Configuration::getEnum(Variables::OTEL_METRICS_EXEMPLAR_FILTER));
+
+        return MeterProvider::builder()
+            ->setResource($resource)
+            ->addReader($reader)
+            ->setExemplarFilter($exemplarFilter)
+            ->build();
+    }
+
+    private function createExemplarFilter(string $name): ExemplarFilterInterface
+    {
+        switch ($name) {
+            case KnownValues::VALUE_WITH_SAMPLED_TRACE:
+                return new WithSampledTraceExemplarFilter();
+            case KnownValues::VALUE_ALL:
+                return new AllExemplarFilter();
+            case KnownValues::VALUE_NONE:
+                return new NoneExemplarFilter();
+            default:
+                self::logWarning('Unknown exemplar filter: ' . $name);
+
+                return new NoneExemplarFilter();
+        }
+    }
+}

src/SDK/Metrics/MetricExporter/NoopMetricExporter.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Metrics\MetricExporter;
+
+use OpenTelemetry\SDK\Metrics\MetricExporterInterface;
+use OpenTelemetry\SDK\Metrics\MetricMetadataInterface;
+
+class NoopMetricExporter implements MetricExporterInterface
+{
+
+    /**
+     * @inheritDoc
+     */
+    public function temporality(MetricMetadataInterface $metric)
+    {
+        return $metric->temporality();
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function export(iterable $batch): bool
+    {
+        return true;
+    }
+
+    public function shutdown(): bool
+    {
+        return true;
+    }
+
+    public function forceFlush(): bool
+    {
+        return true;
+    }
+}

src/SDK/Propagation/PropagatorFactory.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Propagation;
+
+use OpenTelemetry\Context\Propagation\MultiTextMapPropagator;
+use OpenTelemetry\Context\Propagation\NoopTextMapPropagator;
+use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
+use OpenTelemetry\SDK\Behavior\LogsMessagesTrait;
+use OpenTelemetry\SDK\Common\Configuration\Configuration;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+
+class PropagatorFactory
+{
+    use LogsMessagesTrait;
+
+    private const KNOWN_PROPAGATORS = [
+        KnownValues::VALUE_TRACECONTEXT => ['\OpenTelemetry\API\Trace\Propagation\TraceContextPropagator', 'getInstance'],
+        KnownValues::VALUE_BAGGAGE => ['\OpenTelemetry\API\Baggage\Propagation\BaggagePropagator', 'getInstance'],
+        KnownValues::VALUE_B3 => ['\OpenTelemetry\Extension\Propagator\B3\B3Propagator', 'getB3SingleHeaderInstance'],
+        KnownValues::VALUE_B3_MULTI => ['\OpenTelemetry\Extension\Propagator\B3\B3Propagator', 'getB3MultiHeaderInstance'],
+    ];
+
+    public function create(): TextMapPropagatorInterface
+    {
+        $propagators = Configuration::getList(Variables::OTEL_PROPAGATORS);
+        switch (count($propagators)) {
+            case 0:
+                return new NoopTextMapPropagator();
+            case 1:
+                return $this->buildPropagator($propagators[0]) ?? new NoopTextMapPropagator();
+            default:
+                return new MultiTextMapPropagator($this->buildPropagators($propagators));
+        }
+    }
+
+    /**
+     * @return array<TextMapPropagatorInterface>
+     */
+    private function buildPropagators(array $names): array
+    {
+        $propagators = [];
+        foreach ($names as $name) {
+            $propagator = $this->buildPropagator($name);
+            if ($propagator !== null) {
+                $propagators[] = $propagator;
+            }
+        }
+
+        return $propagators;
+    }
+
+    private function buildPropagator(string $name): ?TextMapPropagatorInterface
+    {
+        switch ($name) {
+            case KnownValues::VALUE_NONE:
+                return null;
+            case KnownValues::VALUE_XRAY:
+            case KnownValues::VALUE_OTTRACE:
+                self::logWarning('Unimplemented propagator: ' . $name);
+
+                return null;
+            default:
+                if (!array_key_exists($name, self::KNOWN_PROPAGATORS)) {
+                    self::logWarning('Unknown propagator: ' . $name);
+
+                    return null;
+                }
+                $parts = self::KNOWN_PROPAGATORS[$name];
+
+                try {
+                    return call_user_func($parts);
+                } catch (\Throwable $e) {
+                    self::logError(sprintf('Unable to create %s propagator: %s', $name, $e->getMessage()));
+
+                    return null;
+                }
+
+        }
+    }
+}

src/SDK/README.md

@@ -1 +1,34 @@
-# OpenTelemetry SDK
+# OpenTelemetry SDK
+
+The OpenTelemetry PHP SDK implements the API, and should be used in conjunction with contributed exporter(s) to generate and export telemetry.
+
+## Getting started
+
+### Manual setup
+
+See https://github.com/open-telemetry/opentelemetry-php/tree/main/examples
+
+### SDK Builder
+
+See https://github.com/open-telemetry/opentelemetry-php/blob/main/examples/sdk_builder.php
+
+### Autoloading
+
+SDK autoloading works with configuration values provided via the environment (or php.ini).
+
+The SDK can be automatically created and registered, if the following conditions are met:
+- `OTEL_PHP_AUTOLOAD_ENABLED=true`
+- all required [SDK configuration](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/sdk-environment-variables.md#general-sdk-configuration) is provided
+
+SDK autoloading will be attempted as part of composer's autoloader:
+
+```php
+require 'vendor/autoload.php';
+
+$tracer = OpenTelemetry\API\Common\Instrumentation\Globals::tracerProvider()->getTracer('example');
+$meter = OpenTelemetry\API\Common\Instrumentation\Globals::meterProvider()->getMeter('example');
+```
+
+If autoloading was not successful (or partially successful), no-op implementations of the above may be returned.
+
+See https://github.com/open-telemetry/opentelemetry-php/blob/main/examples/autoload_sdk.php for a more detailed example.

src/SDK/Resource/Detectors/Environment.php

@@ -19,7 +19,7 @@ final class Environment implements ResourceDetectorInterface
     public function getResource(): ResourceInfo
     {
         $attributes = Configuration::has(Variables::OTEL_RESOURCE_ATTRIBUTES)
-            ? Configuration::getMap(Variables::OTEL_RESOURCE_ATTRIBUTES, '')
+            ? Configuration::getMap(Variables::OTEL_RESOURCE_ATTRIBUTES, [])
             : [];
 
         //@see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/sdk-environment-variables.md#general-sdk-configuration

src/SDK/SdkAutoloader.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK;
+
+use InvalidArgumentException;
+use OpenTelemetry\API\Common\Instrumentation\Configurator;
+use OpenTelemetry\API\Common\Instrumentation\Globals;
+use OpenTelemetry\SDK\Common\Configuration\Configuration;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Common\Util\ShutdownHandler;
+use OpenTelemetry\SDK\Metrics\MeterProviderFactory;
+use OpenTelemetry\SDK\Propagation\PropagatorFactory;
+use OpenTelemetry\SDK\Trace\ExporterFactory;
+use OpenTelemetry\SDK\Trace\SamplerFactory;
+use OpenTelemetry\SDK\Trace\SpanProcessorFactory;
+use OpenTelemetry\SDK\Trace\TracerProviderBuilder;
+
+class SdkAutoloader
+{
+    private static ?bool $enabled = null;
+
+    public static function autoload(): bool
+    {
+        try {
+            self::$enabled ??= Configuration::getBoolean(Variables::OTEL_PHP_AUTOLOAD_ENABLED);
+        } catch (InvalidArgumentException $e) {
+            //invalid setting, assume false
+            self::$enabled = false;
+        }
+        if (!self::$enabled) {
+            return false;
+        }
+        Globals::registerInitializer(function (Configurator $configurator) {
+            $exporter = (new ExporterFactory())->fromEnvironment();
+            $propagator = (new PropagatorFactory())->create();
+            $meterProvider = (new MeterProviderFactory())->create();
+            $spanProcessor = (new SpanProcessorFactory())->fromEnvironment($exporter, $meterProvider);
+            $tracerProvider = (new TracerProviderBuilder())
+                ->addSpanProcessor($spanProcessor)
+                ->setSampler((new SamplerFactory())->fromEnvironment())
+                ->build();
+
+            ShutdownHandler::register([$tracerProvider, 'shutdown']);
+            ShutdownHandler::register([$meterProvider, 'shutdown']);
+
+            return $configurator
+                ->withTracerProvider($tracerProvider)
+                ->withMeterProvider($meterProvider)
+                ->withPropagator($propagator);
+        });
+
+        return true;
+    }
+
+    /**
+     * @internal
+     */
+    public static function shutdown(): void
+    {
+        self::$enabled = null;
+    }
+}

src/SDK/SdkBuilder.php

@@ -9,7 +9,6 @@ use OpenTelemetry\Context\Context;
 use OpenTelemetry\Context\Propagation\NoopTextMapPropagator;
 use OpenTelemetry\Context\Propagation\TextMapPropagatorInterface;
 use OpenTelemetry\Context\ScopeInterface;
-use OpenTelemetry\SDK\Common\Future\CancellationInterface;
 use OpenTelemetry\SDK\Common\Util\ShutdownHandler;
 use OpenTelemetry\SDK\Metrics\MeterProviderInterface;
 use OpenTelemetry\SDK\Metrics\NoopMeterProvider;
@@ -59,8 +58,9 @@ class SdkBuilder
         $tracerProvider = $this->tracerProvider ?? new NoopTracerProvider();
         $meterProvider = $this->meterProvider ?? new NoopMeterProvider();
         if ($this->autoShutdown) {
-            ShutdownHandler::register(fn (?CancellationInterface $cancellation = null): bool => $tracerProvider->shutdown($cancellation));
-            ShutdownHandler::register(fn (): bool => $meterProvider->shutdown());
+            // rector rule disabled in config, because ShutdownHandler::register() does not keep a strong reference to $this
+            ShutdownHandler::register([$tracerProvider, 'shutdown']);
+            ShutdownHandler::register([$meterProvider, 'shutdown']);
         }
 
         return new Sdk(
@@ -79,6 +79,7 @@ class SdkBuilder
             ->withMeterProvider($sdk->getMeterProvider())
             ->storeInContext();
 
+        // @todo could auto-shutdown self?
         return Context::storage()->attach($context);
     }
 }

src/SDK/Trace/SpanProcessorFactory.php

@@ -9,13 +9,15 @@ use OpenTelemetry\SDK\Common\Configuration\Configuration;
 use OpenTelemetry\SDK\Common\Configuration\KnownValues as Values;
 use OpenTelemetry\SDK\Common\Configuration\Variables as Env;
 use OpenTelemetry\SDK\Common\Time\ClockFactory;
+use OpenTelemetry\SDK\Metrics\MeterProviderInterface;
+use OpenTelemetry\SDK\Metrics\NoopMeterProvider;
 use OpenTelemetry\SDK\Trace\SpanProcessor\BatchSpanProcessor;
 use OpenTelemetry\SDK\Trace\SpanProcessor\NoopSpanProcessor;
 use OpenTelemetry\SDK\Trace\SpanProcessor\SimpleSpanProcessor;
 
 class SpanProcessorFactory
 {
-    public function fromEnvironment(?SpanExporterInterface $exporter = null): SpanProcessorInterface
+    public function fromEnvironment(?SpanExporterInterface $exporter = null, ?MeterProviderInterface $meterProvider = null): SpanProcessorInterface
     {
         if ($exporter === null) {
             return new NoopSpanProcessor();
@@ -31,6 +33,8 @@ class SpanProcessorFactory
                     Configuration::getInt(Env::OTEL_BSP_SCHEDULE_DELAY, BatchSpanProcessor::DEFAULT_SCHEDULE_DELAY),
                     Configuration::getInt(Env::OTEL_BSP_EXPORT_TIMEOUT, BatchSpanProcessor::DEFAULT_EXPORT_TIMEOUT),
                     Configuration::getInt(Env::OTEL_BSP_MAX_EXPORT_BATCH_SIZE, BatchSpanProcessor::DEFAULT_MAX_EXPORT_BATCH_SIZE),
+                    true, //autoflush
+                    $meterProvider ?? new NoopMeterProvider(),
                 );
             case Values::VALUE_SIMPLE:
                 return new SimpleSpanProcessor($exporter);

src/SDK/_autoload.php

@@ -0,0 +1,5 @@
+<?php
+
+declare(strict_types=1);
+
+\OpenTelemetry\SDK\SdkAutoloader::autoload();

src/SDK/composer.json

@@ -30,7 +30,8 @@
             "OpenTelemetry\\SDK\\": "."
         },
         "files": [
-            "Common/Util/functions.php"
+            "Common/Util/functions.php",
+            "_autoload.php"
         ]
     },
     "suggest": {

tests/Unit/SDK/Common/Configuration/ConfigurationTest.php

@@ -51,6 +51,16 @@ class ConfigurationTest extends TestCase
     ];
 
     private const USER_VALUES = [
+        VariableTypes::STRING => ['foo', 'foo'],
+        VariableTypes::BOOL => ['true', true],
+        VariableTypes::INTEGER => ['42', 42],
+        VariableTypes::ENUM => ['val1', 'val1'],
+        VariableTypes::LIST => [['val1', 'val2'], ['val1','val2']],
+        VariableTypes::MAP => [['var1' => 'val1', 'var2' => 'val2'], ['var1'=>'val1','var2'=>'val2']],
+        VariableTypes::MIXED => ['foo', 'foo'],
+    ];
+
+    private const USER_ENV_VALUES = [
         VariableTypes::STRING => ['foo', 'foo'],
         VariableTypes::BOOL => ['true', true],
         VariableTypes::INTEGER => ['42', 42],
@@ -210,7 +220,7 @@ class ConfigurationTest extends TestCase
     }
 
     /**
-     * @dataProvider userValueProvider
+     * @dataProvider userEnvValueProvider
      */
     public function test_return_user_env_vars(string $methodName, string $variable, string $value, $result)
     {
@@ -225,7 +235,7 @@ class ConfigurationTest extends TestCase
     /**
      * @dataProvider userValueProvider
      */
-    public function test_return_user_default_value(string $methodName, string $variable, string $defaultValue, $result)
+    public function test_return_user_default_value(string $methodName, string $variable, $defaultValue, $result)
     {
         $this->assertSame(
             $result,
@@ -288,6 +298,20 @@ class ConfigurationTest extends TestCase
         }
     }
 
+    public function userEnvValueProvider(): Generator
+    {
+        foreach (self::USER_ENV_VALUES as $varType => $values) {
+            [$default, $result] = $values;
+
+            yield $varType => [
+                self::METHOD_NAMES[$varType][0],
+                self::TYPES[$varType][0],
+                $default,
+                $result,
+            ];
+        }
+    }
+
     public function libraryDefaultValueProvider(): Generator
     {
         foreach (self::LIBRARY_DEFAULTS as $varType => $values) {

tests/Unit/SDK/Metrics/MeterProviderFactoryTest.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Example\Unit\SDK\Metrics;
+
+use AssertWell\PHPUnitGlobalState\EnvironmentVariables;
+use OpenTelemetry\API\Metrics\MeterInterface;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Metrics\MeterProviderFactory;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers \OpenTelemetry\SDK\Metrics\MeterProviderFactory
+ */
+class MeterProviderFactoryTest extends TestCase
+{
+    use EnvironmentVariables;
+
+    public function tearDown(): void
+    {
+        $this->restoreEnvironmentVariables();
+    }
+
+    /**
+     * @dataProvider exporterProvider
+     * @psalm-suppress ArgumentTypeCoercion
+     */
+    public function test_create(string $exporter): void
+    {
+        $_SERVER[Variables::OTEL_METRICS_EXPORTER] = $exporter;
+        $provider = (new MeterProviderFactory())->create();
+        $this->assertInstanceOf(MeterInterface::class, $provider->getMeter('test'));
+    }
+
+    public function exporterProvider(): array
+    {
+        return [
+            'otlp' => [KnownValues::VALUE_OTLP],
+            'none' => [KnownValues::VALUE_NONE],
+            'unimplemented' => ['foo'],
+        ];
+    }
+}

tests/Unit/SDK/Propagation/PropagatorFactoryTest.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Tests\Unit\SDK\Propagation;
+
+use AssertWell\PHPUnitGlobalState\EnvironmentVariables;
+use OpenTelemetry\API\Baggage\Propagation\BaggagePropagator;
+use OpenTelemetry\API\Trace\Propagation\TraceContextPropagator;
+use OpenTelemetry\Context\Propagation\MultiTextMapPropagator;
+use OpenTelemetry\Context\Propagation\NoopTextMapPropagator;
+use OpenTelemetry\Extension\Propagator\B3\B3Propagator;
+use OpenTelemetry\SDK\Common\Configuration\KnownValues;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\Propagation\PropagatorFactory;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers OpenTelemetry\SDK\Propagation\PropagatorFactory
+ */
+class PropagatorFactoryTest extends TestCase
+{
+    use EnvironmentVariables;
+
+    public function tearDown(): void
+    {
+        $this->restoreEnvironmentVariables();
+    }
+
+    /**
+     * @dataProvider propagatorsProvider
+     * @psalm-suppress ArgumentTypeCoercion
+     */
+    public function test_create(string $propagators, string $expected): void
+    {
+        $this->setEnvironmentVariable(Variables::OTEL_PROPAGATORS, $propagators);
+        $propagator = (new PropagatorFactory())->create();
+        $this->assertInstanceOf($expected, $propagator);
+    }
+
+    public function propagatorsProvider(): array
+    {
+        return [
+            [KnownValues::VALUE_BAGGAGE, BaggagePropagator::class],
+            [KnownValues::VALUE_TRACECONTEXT, TraceContextPropagator::class],
+            [KnownValues::VALUE_B3, B3Propagator::class],
+            [KnownValues::VALUE_B3_MULTI, B3Propagator::class],
+            [KnownValues::VALUE_NONE, NoopTextMapPropagator::class],
+            [sprintf('%s,%s', KnownValues::VALUE_B3, KnownValues::VALUE_BAGGAGE), MultiTextMapPropagator::class],
+            ['unknown', NoopTextMapPropagator::class],
+        ];
+    }
+
+    /**
+     * @dataProvider unimplementedPropagatorProvider
+     */
+    public function test_unimplemented_propagators(string $propagator): void
+    {
+        $this->setEnvironmentVariable(Variables::OTEL_PROPAGATORS, $propagator);
+        $propagator = (new PropagatorFactory())->create();
+        $this->assertInstanceOf(NoopTextMapPropagator::class, $propagator);
+    }
+
+    public function unimplementedPropagatorProvider(): array
+    {
+        return [
+            [KnownValues::VALUE_OTTRACE],
+            [KnownValues::VALUE_XRAY],
+        ];
+    }
+}

tests/Unit/SDK/SdkAutoloaderTest.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Tests\Unit\SDK;
+
+use AssertWell\PHPUnitGlobalState\EnvironmentVariables;
+use OpenTelemetry\SDK\Common\Configuration\Variables;
+use OpenTelemetry\SDK\SdkAutoloader;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers \OpenTelemetry\SDK\SdkAutoloader
+ */
+class SdkAutoloaderTest extends TestCase
+{
+    use EnvironmentVariables;
+
+    public function tearDown(): void
+    {
+        SdkAutoloader::shutdown();
+        $this->restoreEnvironmentVariables();
+    }
+
+    public function test_disabled_by_default(): void
+    {
+        $this->assertFalse(SdkAutoloader::autoload());
+    }
+
+    public function test_enabled(): void
+    {
+        $this->setEnvironmentVariable(Variables::OTEL_PHP_AUTOLOAD_ENABLED, 'true');
+        $this->assertTrue(SdkAutoloader::autoload());
+    }
+
+    public function test_disabled_with_invalid_flag(): void
+    {
+        $this->setEnvironmentVariable(Variables::OTEL_PHP_AUTOLOAD_ENABLED, 'invalid-value');
+        $this->assertFalse(SdkAutoloader::autoload());
+    }
+}