Fixes and test updates.

build/Common.props

@@ -37,7 +37,8 @@
     <MicrosoftCodeCoveragePkgVer>[17.4.1]</MicrosoftCodeCoveragePkgVer>
     <MicrosoftExtensionsDependencyInjectionPkgVer>[3.1.0,)</MicrosoftExtensionsDependencyInjectionPkgVer>
     <MicrosoftExtensionsDependencyInjectionAbstractionsPkgVer>$(MicrosoftExtensionsDependencyInjectionPkgVer)</MicrosoftExtensionsDependencyInjectionAbstractionsPkgVer>
-    <MicrosoftExtensionsHostingAbstractionsPkgVer>[2.1.0,)</MicrosoftExtensionsHostingAbstractionsPkgVer>
+    <MicrosoftExtensionsHostingPkgVer>[2.1.0,)</MicrosoftExtensionsHostingPkgVer>
+    <MicrosoftExtensionsHostingAbstractionsPkgVer>$(MicrosoftExtensionsHostingPkgVer)</MicrosoftExtensionsHostingAbstractionsPkgVer>
     <MicrosoftExtensionsLoggingPkgVer>[3.1.0,)</MicrosoftExtensionsLoggingPkgVer>
     <MicrosoftExtensionsLoggingConfigurationPkgVer>$(MicrosoftExtensionsLoggingPkgVer)</MicrosoftExtensionsLoggingConfigurationPkgVer>
     <MicrosoftExtensionsOptionsPkgVer>[3.1.0,)</MicrosoftExtensionsOptionsPkgVer>

src/OpenTelemetry/Internal/EnvironmentVariables/EnvironmentVariablesExtensions.cs

@@ -4,49 +4,24 @@
 
 #nullable enable
 
-using System;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Configuration.EnvironmentVariables;
 
-namespace Microsoft.Extensions.Configuration
+namespace OpenTelemetry.Internal;
+
+/// <summary>
+/// Extension methods for registering <see cref="EnvironmentVariablesConfigurationProvider"/> with <see cref="IConfigurationBuilder"/>.
+/// </summary>
+internal static class EnvironmentVariablesExtensions
 {
     /// <summary>
-    /// Extension methods for registering <see cref="EnvironmentVariablesConfigurationProvider"/> with <see cref="IConfigurationBuilder"/>.
+    /// Adds an <see cref="IConfigurationProvider"/> that reads configuration values from environment variables.
     /// </summary>
-    internal static class EnvironmentVariablesExtensions
+    /// <param name="configurationBuilder">The <see cref="IConfigurationBuilder"/> to add to.</param>
+    /// <returns>The <see cref="IConfigurationBuilder"/>.</returns>
+    public static IConfigurationBuilder AddEnvironmentVariables(this IConfigurationBuilder configurationBuilder)
     {
-        /// <summary>
-        /// Adds an <see cref="IConfigurationProvider"/> that reads configuration values from environment variables.
-        /// </summary>
-        /// <param name="configurationBuilder">The <see cref="IConfigurationBuilder"/> to add to.</param>
-        /// <returns>The <see cref="IConfigurationBuilder"/>.</returns>
-        public static IConfigurationBuilder AddEnvironmentVariables(this IConfigurationBuilder configurationBuilder)
-        {
-            configurationBuilder.Add(new EnvironmentVariablesConfigurationSource());
-            return configurationBuilder;
-        }
-
-        /// <summary>
-        /// Adds an <see cref="IConfigurationProvider"/> that reads configuration values from environment variables
-        /// with a specified prefix.
-        /// </summary>
-        /// <param name="configurationBuilder">The <see cref="IConfigurationBuilder"/> to add to.</param>
-        /// <param name="prefix">The prefix that environment variable names must start with. The prefix will be removed from the environment variable names.</param>
-        /// <returns>The <see cref="IConfigurationBuilder"/>.</returns>
-        public static IConfigurationBuilder AddEnvironmentVariables(
-            this IConfigurationBuilder configurationBuilder,
-            string? prefix)
-        {
-            configurationBuilder.Add(new EnvironmentVariablesConfigurationSource { Prefix = prefix });
-            return configurationBuilder;
-        }
-
-        /// <summary>
-        /// Adds an <see cref="IConfigurationProvider"/> that reads configuration values from environment variables.
-        /// </summary>
-        /// <param name="builder">The <see cref="IConfigurationBuilder"/> to add to.</param>
-        /// <param name="configureSource">Configures the source.</param>
-        /// <returns>The <see cref="IConfigurationBuilder"/>.</returns>
-        public static IConfigurationBuilder AddEnvironmentVariables(this IConfigurationBuilder builder, Action<EnvironmentVariablesConfigurationSource>? configureSource)
-            => builder.Add(configureSource);
+        configurationBuilder.Add(new EnvironmentVariablesConfigurationSource());
+        return configurationBuilder;
     }
 }

src/OpenTelemetry/Internal/HostingHelper.cs

@@ -31,31 +31,17 @@ internal static class HostingHelper
 {
     private static readonly object LockObject = new();
     private static bool initialized;
+    private static Type? hostedServiceImplementation;
 
     public static void AddOpenTelemetryHostedServiceIntoServiceCollection(IServiceCollection services)
     {
-        lock (LockObject)
+        if (TryAddOpenTelemetryHostedServiceIntoServiceCollection(services, out var reason))
         {
-            if (!initialized)
-            {
-                try
-                {
-                    if (TryAddOpenTelemetryHostedServiceIntoServiceCollection(services, out var reason))
-                    {
-                        OpenTelemetrySdkEventSource.Log.HostedServiceRegistered();
-                    }
-                    else
-                    {
-                        OpenTelemetrySdkEventSource.Log.HostedServiceRegistrationSkipped(reason);
-                    }
-                }
-                catch (Exception ex)
-                {
-                    OpenTelemetrySdkEventSource.Log.HostedServiceRegistrationFailure(ex);
-                }
-
-                initialized = true;
-            }
+            OpenTelemetrySdkEventSource.Log.HostedServiceRegistered();
+        }
+        else
+        {
+            OpenTelemetrySdkEventSource.Log.HostedServiceRegistrationSkipped(reason);
         }
     }
 
@@ -67,7 +53,6 @@ private static bool TryAddOpenTelemetryHostedServiceIntoServiceCollection(IServi
         // Note: This is for .NET Framework and/or .NET Standard 2.0 targets.
         bool isDynamicCodeSupported = true;
 #endif
-
         if (!isDynamicCodeSupported)
         {
             reason = "Dynamic code not supported";
@@ -83,8 +68,33 @@ private static bool TryAddOpenTelemetryHostedServiceIntoServiceCollection(IServi
             return false;
         }
 
+        lock (LockObject)
+        {
+            if (!initialized)
+            {
+                try
+                {
+                    hostedServiceImplementation = CreateHostedServiceImplementation(iHostedServiceType);
+                }
+                catch (Exception ex)
+                {
+                    OpenTelemetrySdkEventSource.Log.HostedServiceRegistrationFailure(ex);
+                }
+                finally
+                {
+                    initialized = true;
+                }
+            }
+        }
+
+        if (hostedServiceImplementation == null)
+        {
+            reason = "Initialization failure";
+            return false;
+        }
+
         services.TryAddSingleton<TelemetryHostedService>();
-        services.TryAddSingleton(iHostedServiceType, CreateHostedServiceImplementation(iHostedServiceType));
+        services.TryAddSingleton(iHostedServiceType, hostedServiceImplementation);
 
         reason = null;
         return true;

test/OpenTelemetry.Extensions.Hosting.Tests/InMemoryExporterMetricsExtensionsTests.cs

@@ -16,11 +16,8 @@
 
 #if NET6_0_OR_GREATER
 
-using System;
-using System.Collections.Generic;
 using System.Diagnostics.Metrics;
 using System.Net;
-using System.Threading.Tasks;
 
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
@@ -89,7 +86,7 @@ private static async Task RunMetricsTest(Action<MeterProviderBuilder> configure,
             using var host = await new HostBuilder()
                .ConfigureWebHost(webBuilder => webBuilder
                    .UseTestServer()
-                   .ConfigureServices(services => services.AddOpenTelemetry().WithMetrics(configure).StartWithHost())
+                   .ConfigureServices(services => services.AddOpenTelemetry().WithMetrics(configure))
                    .Configure(app => app.Run(httpContext =>
                    {
                        testAction.Invoke();