Set Elastic User-Agent header on exporter options

src/Elastic.OpenTelemetry.AutoInstrumentation/AutoInstrumentationPlugin.cs

@@ -5,9 +5,12 @@
 using Elastic.OpenTelemetry.Configuration;
 using Elastic.OpenTelemetry.Core;
 using Elastic.OpenTelemetry.Diagnostics;
+using Elastic.OpenTelemetry.Exporters;
 using Elastic.OpenTelemetry.Resources;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using OpenTelemetry;
+using OpenTelemetry.Exporter;
 using OpenTelemetry.Logs;
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
@@ -39,6 +42,8 @@ public TracerProviderBuilder BeforeConfigureTracerProvider(TracerProviderBuilder
 		{
 			builder.ConfigureResource(r => r.WithElasticDefaultsCore(_components, null, null));
 
+			builder.ConfigureServices(sc => sc.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions));
+
 			CoreTracerProvderBuilderExtensions.AddActivitySourceWithLogging(builder, logger, "Elastic.Transport", "<n/a>");
 			CoreTracerProvderBuilderExtensions.AddElasticProcessorsCore(builder, null, _components, null);
 
@@ -66,6 +71,8 @@ public MeterProviderBuilder BeforeConfigureMeterProvider(MeterProviderBuilder bu
 		{
 			builder.ConfigureResource(r => r.WithElasticDefaultsCore(_components, null, null));
 
+			builder.ConfigureServices(sc => sc.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions));
+
 			logger.LogConfiguredSignalProvider(nameof(Signals.Metrics), nameof(MeterProviderBuilder), "<n/a>");
 
 			return builder;

src/Elastic.OpenTelemetry.AutoInstrumentation/Elastic.OpenTelemetry.AutoInstrumentation.csproj

@@ -24,6 +24,7 @@
 
   <!-- We need these dependencies when building agianst all targets. As they are private, we don't have to worry about them being packaged. -->
   <ItemGroup>
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.11.2" PrivateAssets="all" />
     <PackageReference Include="Polyfill" Version="7.21.0" PrivateAssets="all" IncludeAssets="runtime; build; native; contentfiles; analyzers; buildtransitive" />
     <PackageReference Include="NetEscapades.EnumGenerators" Version="1.0.0-beta09" PrivateAssets="all" ExcludeAssets="runtime" />
   </ItemGroup>

src/Elastic.OpenTelemetry.Core/Exporters/ElasticUserAgentHandler.cs

@@ -0,0 +1,22 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+#if NETFRAMEWORK
+using System.Net.Http;
+#endif
+
+namespace Elastic.OpenTelemetry.Exporters;
+
+internal class ElasticUserAgentHandler(string userAgent) : HttpClientHandler
+{
+	private readonly string _userAgent = userAgent;
+
+	protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+	{
+		request.Headers.Remove("User-Agent");
+		request.Headers.Add("User-Agent", _userAgent);
+
+		return base.SendAsync(request, cancellationToken);
+	}
+}

src/Elastic.OpenTelemetry.Core/Exporters/OtlpExporterDefaults.cs

@@ -0,0 +1,24 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using Elastic.OpenTelemetry.Core;
+using OpenTelemetry.Exporter;
+
+#if NETFRAMEWORK
+using System.Net.Http;
+#endif
+
+namespace Elastic.OpenTelemetry.Exporters;
+
+internal static class OtlpExporterDefaults
+{
+	internal static readonly HttpMessageHandler Handler = new ElasticUserAgentHandler($"elastic-otlp-dotnet/{VersionHelper.InformationalVersion}");
+
+	public static void OtlpExporterOptions(OtlpExporterOptions options) =>
+		options.HttpClientFactory = () =>
+		{
+			var client = new HttpClient(Handler);
+			return client;
+		};
+}

src/Elastic.OpenTelemetry.Core/Extensions/ResourceBuilderExtensions.cs

@@ -21,7 +21,7 @@ internal static class ResourceBuilderExtensions
 
 	/// <summary>
 	/// Used to track the number of times any variation of `WithElasticDefaults` is invoked by consuming
-	/// code acrosss all <see cref="ResourceBuilder"/> instances. This allows us to warn about potenital
+	/// code across all <see cref="ResourceBuilder"/> instances. This allows us to warn about potential
 	/// misconfigurations.
 	/// </summary>
 	private static int WithElasticDefaultsCallCount;

src/Elastic.OpenTelemetry/Elastic.OpenTelemetry.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Library</OutputType>
@@ -47,6 +47,10 @@
     <!-- We skip this on .NET since we prefer to use the native instrumentation from the built in ActivitySource -->
     <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.11.1" />
   </ItemGroup>
+
+  <ItemGroup>
+    <Reference Include="System.Net.Http" Condition="'$(TargetFramework)' == 'net462'" />
+  </ItemGroup>
 
   <ItemGroup>
     <InternalsVisibleTo Include="Elastic.OpenTelemetry.Tests" Key="$(ExposedPublicKey)" />

src/Elastic.OpenTelemetry/Extensions/LoggingProviderBuilderExtensions.cs

@@ -7,13 +7,16 @@
 using Elastic.OpenTelemetry.Configuration;
 using Elastic.OpenTelemetry.Core;
 using Elastic.OpenTelemetry.Diagnostics;
+using Elastic.OpenTelemetry.Exporters;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using OpenTelemetry.Exporter;
+using OpenTelemetry.Logs;
 using OpenTelemetry.Resources;
 
 // Matching namespace with LoggerProviderBuilder
 #pragma warning disable IDE0130 // Namespace does not match folder structure
-namespace OpenTelemetry.Logs;
+namespace OpenTelemetry;
 #pragma warning restore IDE0130 // Namespace does not match folder structure
 
 /// <summary>
@@ -24,7 +27,7 @@ public static class LoggingProviderBuilderExtensions
 {
 	/// <summary>
 	/// Used to track the number of times any variation of `WithElasticDefaults` is invoked by consuming
-	/// code acrosss all <see cref="LoggerProviderBuilder"/> instances. This allows us to warn about potenital
+	/// code across all <see cref="LoggerProviderBuilder"/> instances. This allows us to warn about potential
 	/// misconfigurations.
 	/// </summary>
 	private static int WithElasticDefaultsCallCount;
@@ -149,6 +152,9 @@ static void ConfigureBuilder(LoggerProviderBuilder builder, BuilderState builder
 
 			builder.ConfigureResource(r => r.WithElasticDefaults(builderState, services));
 
+			if (services is null)
+				builder.ConfigureServices(sc => sc.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions));
+
 			if (components.Options.SkipOtlpExporter)
 			{
 				logger.LogSkippingOtlpExporter(nameof(Signals.Logs), loggingProviderName, builderState.InstanceIdentifier);

src/Elastic.OpenTelemetry/Extensions/MeterProviderBuilderExtensions.cs

@@ -8,17 +8,19 @@
 using Elastic.OpenTelemetry.Configuration;
 using Elastic.OpenTelemetry.Core;
 using Elastic.OpenTelemetry.Diagnostics;
+using Elastic.OpenTelemetry.Exporters;
 using Elastic.OpenTelemetry.Instrumentation;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using OpenTelemetry.Exporter;
 using OpenTelemetry.Logs;
+using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
-using OpenTelemetry.Trace;
 
 // Matching namespace with MeterProviderBuilder
 #pragma warning disable IDE0130 // Namespace does not match folder structure
-namespace OpenTelemetry.Metrics;
+namespace OpenTelemetry;
 #pragma warning restore IDE0130 // Namespace does not match folder structure
 
 /// <summary>
@@ -29,7 +31,7 @@ public static class MeterProviderBuilderExtensions
 {
 	/// <summary>
 	/// Used to track the number of times any variation of `WithElasticDefaults` is invoked by consuming
-	/// code acrosss all <see cref="MeterProviderBuilder"/> instances. This allows us to warn about potenital
+	/// code across all <see cref="MeterProviderBuilder"/> instances. This allows us to warn about potential
 	/// misconfigurations.
 	/// </summary>
 	private static int WithElasticDefaultsCallCount;
@@ -177,6 +179,9 @@ static void ConfigureBuilder(MeterProviderBuilder builder, BuilderState builderS
 
 			builder.ConfigureResource(r => r.WithElasticDefaults(builderState, services));
 
+			if (services is null)
+				builder.ConfigureServices(sc => sc.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions));
+
 #if NET9_0_OR_GREATER
 			// On .NET 9, the contrib HTTP instrumentation is no longer required. If the dependency exists,
 			// it will be registered via the reflection-based assembly scanning.

src/Elastic.OpenTelemetry/Extensions/OpenTelemetryBuilderExtensions.cs

@@ -6,10 +6,12 @@
 using Elastic.OpenTelemetry.Configuration;
 using Elastic.OpenTelemetry.Core;
 using Elastic.OpenTelemetry.Diagnostics;
+using Elastic.OpenTelemetry.Exporters;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Diagnostics.Metrics;
 using Microsoft.Extensions.Logging;
+using OpenTelemetry.Exporter;
 using OpenTelemetry.Logs;
 using OpenTelemetry.Metrics;
 using OpenTelemetry.Resources;
@@ -28,7 +30,7 @@ public static class OpenTelemetryBuilderExtensions
 {
 	/// <summary>
 	/// Used to track the number of times any variation of `WithElasticDefaults` is invoked by consuming
-	/// code acrosss all <see cref="IOpenTelemetryBuilder"/> instances. This allows us to warn about potenital
+	/// code across all <see cref="IOpenTelemetryBuilder"/> instances. This allows us to warn about potential
 	/// misconfigurations.
 	/// </summary>
 	private static int WithElasticDefaultsCallCount;
@@ -138,6 +140,8 @@ private static void ConfigureBuilder(IOpenTelemetryBuilder builder, BuilderState
 		var components = builderState.Components;
 		var options = builderState.Components.Options;
 
+		services?.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions);
+
 		if (options.Signals.HasFlagFast(Signals.Traces))
 		{
 			builder.WithTracing(b => b.WithElasticDefaults(components, builder.Services));

src/Elastic.OpenTelemetry/Extensions/TracerProviderBuilderExtensions.cs

@@ -8,18 +8,18 @@
 using Elastic.OpenTelemetry.Configuration;
 using Elastic.OpenTelemetry.Core;
 using Elastic.OpenTelemetry.Diagnostics;
+using Elastic.OpenTelemetry.Exporters;
 using Elastic.OpenTelemetry.Instrumentation;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
-using OpenTelemetry.Logs;
-using OpenTelemetry.Metrics;
+using OpenTelemetry.Exporter;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
 
 // Matching namespace with TracerProviderBuilder
 #pragma warning disable IDE0130 // Namespace does not match folder structure
-namespace OpenTelemetry.Trace;
+namespace OpenTelemetry;
 #pragma warning restore IDE0130 // Namespace does not match folder structure
 
 /// <summary>
@@ -167,6 +167,9 @@ private static void ConfigureBuilder(TracerProviderBuilder builder, BuilderState
 
 		builder.ConfigureResource(r => r.WithElasticDefaults(builderState, services));
 
+		if (services is null)
+			builder.ConfigureServices(sc => sc.Configure<OtlpExporterOptions>(OtlpExporterDefaults.OtlpExporterOptions));
+
 #if NET9_0_OR_GREATER
 		if (SignalBuilder.InstrumentationAssemblyExists("OpenTelemetry.Instrumentation.Http.dll"))
 		{