adding otlp/file exporter (#1465)

the spec has added in-development otlp file/stdout exporter. We already supported this programmatically, so
add some factories and sdk config to allow configuration from environment (only for stdout, per spec)

StdoutLogsExporterFactory.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Otlp;
+
+use OpenTelemetry\SDK\Common\Export\Stream\StreamTransportFactory;
+use OpenTelemetry\SDK\Logs\LogRecordExporterFactoryInterface;
+use OpenTelemetry\SDK\Logs\LogRecordExporterInterface;
+
+class StdoutLogsExporterFactory implements LogRecordExporterFactoryInterface
+{
+    public function create(): LogRecordExporterInterface
+    {
+        $transport = (new StreamTransportFactory())->create('php://stdout', ContentTypes::NDJSON);
+
+        return new LogsExporter($transport);
+    }
+}

StdoutMetricExporterFactory.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Otlp;
+
+use OpenTelemetry\SDK\Common\Export\Stream\StreamTransportFactory;
+use OpenTelemetry\SDK\Metrics\MetricExporterFactoryInterface;
+use OpenTelemetry\SDK\Metrics\MetricExporterInterface;
+
+class StdoutMetricExporterFactory implements MetricExporterFactoryInterface
+{
+    public function create(): MetricExporterInterface
+    {
+        $transport = (new StreamTransportFactory())->create('php://stdout', ContentTypes::NDJSON);
+
+        return new MetricExporter($transport);
+    }
+}

StdoutSpanExporterFactory.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Otlp;
+
+use OpenTelemetry\SDK\Common\Export\Stream\StreamTransportFactory;
+use OpenTelemetry\SDK\Trace\SpanExporter\SpanExporterFactoryInterface;
+use OpenTelemetry\SDK\Trace\SpanExporterInterface;
+
+class StdoutSpanExporterFactory implements SpanExporterFactoryInterface
+{
+    public function create(): SpanExporterInterface
+    {
+        $transport = (new StreamTransportFactory())->create('php://stdout', ContentTypes::NDJSON);
+
+        return new SpanExporter($transport);
+    }
+}

_register.php

@@ -2,8 +2,12 @@
 
 declare(strict_types=1);
 \OpenTelemetry\SDK\Registry::registerSpanExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\SpanExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerSpanExporterFactory('otlp/stdout', \OpenTelemetry\Contrib\Otlp\StdoutSpanExporterFactory::class);
+
 \OpenTelemetry\SDK\Registry::registerMetricExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\MetricExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerMetricExporterFactory('otlp/stdout', \OpenTelemetry\Contrib\Otlp\StdoutMetricExporterFactory::class);
 
 \OpenTelemetry\SDK\Registry::registerTransportFactory('http', \OpenTelemetry\Contrib\Otlp\OtlpHttpTransportFactory::class);
 
 \OpenTelemetry\SDK\Registry::registerLogRecordExporterFactory('otlp', \OpenTelemetry\Contrib\Otlp\LogsExporterFactory::class);
+\OpenTelemetry\SDK\Registry::registerLogRecordExporterFactory('otlp/stdout', \OpenTelemetry\Contrib\Otlp\StdoutLogsExporterFactory::class);