PoC: Configuration\CompositeResolver and SPI discovery

composer.json

@@ -86,9 +86,9 @@
     },
     "require-dev": {
         "ext-grpc": "*",
-        "grpc/grpc": "^1.30",
         "bamarni/composer-bin-plugin": "^1.8",
         "dg/bypass-finals": "^1.4",
+        "grpc/grpc": "^1.30",
         "guzzlehttp/guzzle": "^7.4",
         "guzzlehttp/psr7": "^2.1",
         "mikey179/vfsstream": "^1.6.11",
@@ -176,6 +176,13 @@
             ],
             "OpenTelemetry\\API\\Instrumentation\\AutoInstrumentation\\Instrumentation": [
                 "OpenTelemetry\\Example\\ExampleInstrumentation"
+            ],
+            "OpenTelemetry\\SDK\\Common\\Configuration\\Resolver\\ResolverInterface": [
+                "OpenTelemetry\\SDK\\Common\\Configuration\\Resolver\\SdkConfigurationResolver"
+            ],
+            "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\EnvSourceProvider": [
+                "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\Adapter\\SymfonyDotenvProvider",
+                "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\Adapter\\VlucasPhpdotenvProvider"
             ]
         }
     }

deptrac.yaml

@@ -107,8 +107,14 @@ deptrac:
                 regex: ^Ramsey\\Uuid\\*
       -   name: NyholmPsr7Server
           collectors:
-              - type: className
-                regex: ^Nyholm\\Psr7Server\\*
+            - type: className
+              regex: ^Nyholm\\Psr7Server\\*
+      -   name: DotenvProvider
+          collectors:
+            - type: className
+              regex: ^Symfony\\Component\\Dotenv\\*
+            - type: className
+              regex: ^Dotenv\\*
 
     ruleset:
       Context:
@@ -124,6 +130,7 @@ deptrac:
           - Context
           - Contrib
           - Extension
+          - DotenvProvider
       API:
           - Context
           - PsrLog

phpstan.neon.dist

@@ -50,4 +50,19 @@ parameters:
         -
             message: "#.*return with type T is not subtype.*#"
             paths:
-                - src/SDK/Common/InstrumentationScope
+                - src/SDK/Common/InstrumentationScope
+
+        -
+            message: "#^Call to (static )?method .* on an unknown class .*#"
+            paths:
+                - src/Config/SDK/Configuration/Environment/Adapter/
+
+        -
+            message: "#^Instantiated class .* not found\\.#"
+            paths:
+                - src/Config/SDK/Configuration/Environment/Adapter/
+
+        -
+            message: "#^Caught class .* not found\\.#"
+            paths:
+                - src/Config/SDK/Configuration/Environment/Adapter/

src/Config/SDK/Configuration.php

@@ -10,10 +10,12 @@
 use OpenTelemetry\Config\SDK\Configuration\ComponentProvider;
 use OpenTelemetry\Config\SDK\Configuration\ConfigurationFactory;
 use OpenTelemetry\Config\SDK\Configuration\Context;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvReader;
 use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceReader;
 use OpenTelemetry\Config\SDK\Configuration\Environment\PhpIniEnvSource;
 use OpenTelemetry\Config\SDK\Configuration\Environment\ServerEnvSource;
 use OpenTelemetry\SDK\SdkBuilder;
+use WeakMap;
 
 final class Configuration
 {
@@ -37,24 +39,28 @@ public static function parseFile(
         string|array $file,
         ?string $cacheFile = null,
         bool $debug = true,
+        ?EnvReader $envReader = null,
     ): Configuration {
-        return new self(self::factory()->parseFile($file, $cacheFile, $debug));
+        return new self(self::factory($envReader)->parseFile($file, $cacheFile, $debug));
     }
 
     /**
      * @return ConfigurationFactory<SdkBuilder>
      */
-    private static function factory(): ConfigurationFactory
+    private static function factory(?EnvReader $envReader): ConfigurationFactory
     {
-        static $factory;
+        static $defaultEnvReader;
+        static $factories = new WeakMap();
 
-        return $factory ??= new ConfigurationFactory(
+        $envReader ??= $defaultEnvReader ??= new EnvSourceReader([
+            new ServerEnvSource(),
+            new PhpIniEnvSource(),
+        ]);
+
+        return $factories[$envReader] ??= new ConfigurationFactory(
             ServiceLoader::load(ComponentProvider::class),
             new OpenTelemetrySdk(),
-            new EnvSourceReader([
-                new ServerEnvSource(),
-                new PhpIniEnvSource(),
-            ]),
+            $envReader,
         );
     }
 }

src/Config/SDK/Configuration/Environment/Adapter/SymfonyDotenvProvider.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Config\SDK\Configuration\Environment\Adapter;
+
+use function array_diff_key;
+use Composer\InstalledVersions;
+use Nevay\SPI\ServiceProviderDependency\PackageDependency;
+use OpenTelemetry\Config\SDK\Configuration\Environment\ArrayEnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceProvider;
+use Symfony\Component\Dotenv\Dotenv;
+use Symfony\Component\Dotenv\Exception\PathException;
+
+#[PackageDependency('symfony/dotenv', '^5.4 || ^6.4 || ^7.0')]
+final class SymfonyDotenvProvider implements EnvSourceProvider
+{
+    /** @psalm-suppress UndefinedClass */
+    public function getEnvSource(): EnvSource
+    {
+        $installPath = InstalledVersions::getRootPackage()['install_path'];
+
+        $backup = [$_SERVER, $_ENV];
+        $env = [];
+
+        try {
+            (new Dotenv())->bootEnv($installPath . '/.env');
+            $env = $_SERVER;
+        } catch (PathException) {
+        } finally {
+            [$_SERVER, $_ENV] = $backup;
+        }
+
+        return new ArrayEnvSource(array_diff_key($env, $_SERVER));
+    }
+}

src/Config/SDK/Configuration/Environment/Adapter/VlucasPhpdotenvProvider.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Config\SDK\Configuration\Environment\Adapter;
+
+use Composer\InstalledVersions;
+use Dotenv\Dotenv;
+use Dotenv\Exception\InvalidPathException;
+use Nevay\SPI\ServiceProviderDependency\PackageDependency;
+use OpenTelemetry\Config\SDK\Configuration\Environment\ArrayEnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceProvider;
+
+#[PackageDependency('vlucas/phpdotenv', '^4.0 || ^5.0')]
+final class VlucasPhpdotenvProvider implements EnvSourceProvider
+{
+    /** @psalm-suppress UndefinedClass */
+    public function getEnvSource(): EnvSource
+    {
+        $backup = [$_SERVER, $_ENV];
+        $env = [];
+
+        try {
+            $env = Dotenv::createImmutable([InstalledVersions::getRootPackage()['install_path']])->load();
+        } catch (InvalidPathException) {
+        } finally {
+            [$_SERVER, $_ENV] = $backup;
+        }
+
+        return new ArrayEnvSource(array_diff_key($env, $_SERVER));
+    }
+}

src/Config/SDK/Configuration/Environment/EnvSourceProvider.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Config\SDK\Configuration\Environment;
+
+interface EnvSourceProvider
+{
+    public function getEnvSource(): EnvSource;
+}

src/Config/SDK/Configuration/Environment/LazyEnvSource.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Config\SDK\Configuration\Environment;
+
+use Closure;
+
+final class LazyEnvSource implements EnvSource
+{
+    /**
+     * @param Closure(): EnvSource|EnvSource $env
+     */
+    public function __construct(
+        private Closure|EnvSource $env,
+    ) {
+    }
+
+    public function readRaw(string $name): mixed
+    {
+        if (!$this->env instanceof EnvSource) {
+            $this->env = ($this->env)();
+        }
+
+        return $this->env->readRaw($name);
+    }
+}

src/Config/SDK/Instrumentation.php

@@ -11,9 +11,11 @@
 use OpenTelemetry\Config\SDK\Configuration\ComponentProvider;
 use OpenTelemetry\Config\SDK\Configuration\ConfigurationFactory;
 use OpenTelemetry\Config\SDK\Configuration\Context;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvReader;
 use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceReader;
 use OpenTelemetry\Config\SDK\Configuration\Environment\PhpIniEnvSource;
 use OpenTelemetry\Config\SDK\Configuration\Environment\ServerEnvSource;
+use WeakMap;
 
 final class Instrumentation
 {
@@ -39,24 +41,28 @@ public static function parseFile(
         string|array $file,
         ?string $cacheFile = null,
         bool $debug = true,
+        ?EnvReader $envReader = null,
     ): Instrumentation {
-        return new self(self::factory()->parseFile($file, $cacheFile, $debug));
+        return new self(self::factory($envReader)->parseFile($file, $cacheFile, $debug));
     }
 
     /**
      * @return ConfigurationFactory<ConfigurationRegistry>
      */
-    private static function factory(): ConfigurationFactory
+    private static function factory(?EnvReader $envReader): ConfigurationFactory
     {
-        static $factory;
+        static $defaultEnvReader;
+        static $factories = new WeakMap();
 
-        return $factory ??= new ConfigurationFactory(
+        $envReader ??= $defaultEnvReader ??= new EnvSourceReader([
+            new ServerEnvSource(),
+            new PhpIniEnvSource(),
+        ]);
+
+        return $factories[$envReader] ??= new ConfigurationFactory(
             ServiceLoader::load(ComponentProvider::class),
             new InstrumentationConfigurationRegistry(),
-            new EnvSourceReader([
-                new ServerEnvSource(),
-                new PhpIniEnvSource(),
-            ]),
+            $envReader,
         );
     }
 }

src/Config/SDK/composer.json

@@ -74,6 +74,10 @@
 
                 "OpenTelemetry\\Config\\SDK\\ComponentProvider\\Instrumentation\\General\\HttpConfigProvider",
                 "OpenTelemetry\\Config\\SDK\\ComponentProvider\\Instrumentation\\General\\PeerConfigProvider"
+            ],
+            "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\EnvSourceProvider": [
+                "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\Adapter\\SymfonyDotenvProvider",
+                "OpenTelemetry\\Config\\SDK\\Configuration\\Environment\\Adapter\\VlucasPhpdotenvProvider"
             ]
         }
     }

src/SDK/Common/Configuration/Resolver/CompositeResolver.php

@@ -4,6 +4,7 @@
 
 namespace OpenTelemetry\SDK\Common\Configuration\Resolver;
 
+use Nevay\SPI\ServiceLoader;
 use OpenTelemetry\SDK\Common\Configuration\Configuration;
 
 /**
@@ -18,6 +19,7 @@ public static function instance(): self
     {
         static $instance;
         $instance ??= new self([
+            ...ServiceLoader::load(ResolverInterface::class),
             new EnvironmentResolver(),
             new PhpIniResolver(),
         ]);

src/SDK/Common/Configuration/Resolver/SdkConfigurationResolver.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Common\Configuration\Resolver;
+
+use Nevay\SPI\ServiceLoader;
+use Nevay\SPI\ServiceProviderDependency\PackageDependency;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceProvider;
+use OpenTelemetry\Config\SDK\Configuration\Environment\EnvSourceReader;
+use OpenTelemetry\Config\SDK\Configuration\Environment\LazyEnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\PhpIniEnvSource;
+use OpenTelemetry\Config\SDK\Configuration\Environment\ServerEnvSource;
+use OpenTelemetry\SDK\Common\Configuration\Configuration;
+
+/**
+ * @internal
+ */
+#[PackageDependency('open-telemetry/sdk-configuration', '*')]
+class SdkConfigurationResolver implements ResolverInterface
+{
+    private readonly EnvSourceReader $reader;
+
+    public function __construct()
+    {
+        $envSources = [];
+        $envSources[] = new ServerEnvSource();
+        $envSources[] = new PhpIniEnvSource();
+
+        /** @var EnvSourceProvider $envSourceProvider */
+        foreach (ServiceLoader::load(EnvSourceProvider::class) as $envSourceProvider) {
+            $envSources[] = new LazyEnvSource($envSourceProvider->getEnvSource(...));
+        }
+
+        $this->reader = new EnvSourceReader($envSources);
+    }
+
+    public function retrieveValue(string $variableName)
+    {
+        return $this->reader->read($variableName);
+    }
+
+    public function hasVariable(string $variableName): bool
+    {
+        return !Configuration::isEmpty($this->reader->read($variableName));
+    }
+}

src/SDK/composer.json

@@ -60,6 +60,9 @@
         "spi": {
             "OpenTelemetry\\API\\Instrumentation\\AutoInstrumentation\\HookManagerInterface": [
                 "OpenTelemetry\\API\\Instrumentation\\AutoInstrumentation\\ExtensionHookManager"
+            ],
+            "OpenTelemetry\\SDK\\Common\\Configuration\\Resolver\\ResolverInterface": [
+                "OpenTelemetry\\SDK\\Common\\Configuration\\Resolver\\SdkConfigurationResolver"
             ]
         }
     }