adding resource detectors to registry (#999)

To enable registering non-SDK resource detectors within the SDK, extend the SDK Registry.
Detectors will be looked up by name and applied as part of 'all', or as part of a list
of detectors

Author: brettmc

Registry.php

@@ -8,6 +8,7 @@
 use OpenTelemetry\SDK\Common\Export\TransportFactoryInterface;
 use OpenTelemetry\SDK\Logs\LogRecordExporterFactoryInterface;
 use OpenTelemetry\SDK\Metrics\MetricExporterFactoryInterface;
+use OpenTelemetry\SDK\Resource\ResourceDetectorInterface;
 use OpenTelemetry\SDK\Trace\SpanExporter\SpanExporterFactoryInterface;
 use RuntimeException;
 
@@ -22,6 +23,7 @@ class Registry
     private static array $metricExporterFactories = [];
     private static array $textMapPropagators = [];
     private static array $logRecordExporterFactories = [];
+    private static array $resourceDetectors = [];
 
     /**
      * @param TransportFactoryInterface|class-string<TransportFactoryInterface> $factory
@@ -91,6 +93,7 @@ public static function registerMetricExporterFactory(string $exporter, $factory,
         }
         self::$metricExporterFactories[$exporter] = $factory;
     }
+
     public static function registerLogRecordExporterFactory(string $exporter, $factory, bool $clobber = false): void
     {
         if (!$clobber && array_key_exists($exporter, self::$logRecordExporterFactories)) {
@@ -119,6 +122,11 @@ public static function registerTextMapPropagator(string $name, TextMapPropagator
         self::$textMapPropagators[$name] = $propagator;
     }
 
+    public static function registerResourceDetector(string $name, ResourceDetectorInterface $detector): void
+    {
+        self::$resourceDetectors[$name] = $detector;
+    }
+
     public static function spanExporterFactory(string $exporter): SpanExporterFactoryInterface
     {
         if (!array_key_exists($exporter, self::$spanExporterFactories)) {
@@ -180,4 +188,21 @@ public static function textMapPropagator(string $name): TextMapPropagatorInterfa
 
         return self::$textMapPropagators[$name];
     }
+
+    public static function resourceDetector(string $name): ResourceDetectorInterface
+    {
+        if (!array_key_exists($name, self::$resourceDetectors)) {
+            throw new RuntimeException('Resource detector not registered for: ' . $name);
+        }
+
+        return self::$resourceDetectors[$name];
+    }
+
+    /**
+     * @return array<int, ResourceDetectorInterface>
+     */
+    public static function resourceDetectors(): array
+    {
+        return array_values(self::$resourceDetectors);
+    }
 }

Resource/ResourceInfoFactory.php

@@ -5,13 +5,18 @@
 namespace OpenTelemetry\SDK\Resource;
 
 use function in_array;
+use OpenTelemetry\API\Behavior\LogsMessagesTrait;
 use OpenTelemetry\SDK\Common\Attribute\Attributes;
 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\Registry;
+use RuntimeException;
 
 class ResourceInfoFactory
 {
+    use LogsMessagesTrait;
+
     /**
      * Merges resources into a new one.
      *
@@ -43,10 +48,10 @@ public static function defaultResource(): ResourceInfo
                 new Detectors\OperatingSystem(),
                 new Detectors\Process(),
                 new Detectors\ProcessRuntime(),
-                new Detectors\Container(),
                 new Detectors\Sdk(),
                 new Detectors\SdkProvided(),
                 new Detectors\Composer(),
+                ...Registry::resourceDetectors(),
                 new Detectors\Environment(),
             ]))->getResource();
         }
@@ -82,17 +87,21 @@ public static function defaultResource(): ResourceInfo
                 case Values::VALUE_DETECTORS_SDK_PROVIDED:
                     $resourceDetectors[] = new Detectors\SdkProvided();
 
-                    break;
-                case Values::VALUE_DETECTORS_CONTAINER:
-                    $resourceDetectors[] = new Detectors\Container();
-
                     break;
 
                 case Values::VALUE_DETECTORS_COMPOSER:
                     $resourceDetectors[] = new Detectors\Composer();
 
+                    break;
+                case Values::VALUE_NONE:
+
                     break;
                 default:
+                    try {
+                        $resourceDetectors[] = Registry::resourceDetector($detector);
+                    } catch (RuntimeException $e) {
+                        self::logWarning($e->getMessage());
+                    }
             }
         }