[Logs] Support dependency injection in ResourceBuilder and load envvars from IConfiguration (#3889)

* Fixed logging resource builder not being attached to IServiceProvider.

* CHANGELOG patch.

Co-authored-by: Alan West <3676547+alanwest@users.noreply.github.com>

src/OpenTelemetry/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+* Added dependency injection support in the `ResourceBuilder` class and added
+  support for loading environment variables from `IConfiguration` for the
+  `AddEnvironmentVariableDetector` extension (Logs)
+  ([#3889](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3889))
+
 ## 1.4.0-beta.3
 
 Released 2022-Nov-07
@@ -17,7 +22,7 @@ Released 2022-Nov-07
 
 * Added dependency injection support in the `ResourceBuilder` class and added
   support for loading environment variables from `IConfiguration` for the
-  `AddEnvironmentVariableDetector` extension
+  `AddEnvironmentVariableDetector` extension (Traces & Metrics)
   ([#3782](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3782),
   [#3798](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3798))
 

src/OpenTelemetry/Logs/OpenTelemetryLoggerProvider.cs

@@ -20,6 +20,7 @@ using System;
 using System.Collections;
 using System.Text;
 using System.Threading;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using OpenTelemetry.Internal;
@@ -58,6 +59,13 @@ namespace OpenTelemetry.Logs
         {
         }
 
+        internal OpenTelemetryLoggerProvider(IServiceProvider serviceProvider)
+            : this(
+                  serviceProvider: serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider)),
+                  options: serviceProvider?.GetRequiredService<IOptionsMonitor<OpenTelemetryLoggerOptions>>().CurrentValue!)
+        {
+        }
+
         internal OpenTelemetryLoggerProvider()
             : this(new OpenTelemetryLoggerOptions())
         {
@@ -68,7 +76,7 @@ namespace OpenTelemetry.Logs
         {
         }
 
-        internal OpenTelemetryLoggerProvider(OpenTelemetryLoggerOptions options)
+        internal OpenTelemetryLoggerProvider(OpenTelemetryLoggerOptions options, IServiceProvider? serviceProvider = null)
         {
             OpenTelemetrySdkEventSource.Log.OpenTelemetryLoggerProviderEvent("Building OpenTelemetryLoggerProvider.");
 
@@ -78,7 +86,9 @@ namespace OpenTelemetry.Logs
             this.IncludeFormattedMessage = options.IncludeFormattedMessage;
             this.ParseStateValues = options.ParseStateValues;
 
-            this.Resource = options.ResourceBuilder.Build();
+            var resourceBuilder = options.ResourceBuilder;
+            resourceBuilder.ServiceProvider = serviceProvider;
+            this.Resource = resourceBuilder.Build();
 
             foreach (var processor in options.Processors)
             {

src/OpenTelemetry/Logs/OpenTelemetryLoggingExtensions.cs

@@ -57,7 +57,9 @@ namespace Microsoft.Extensions.Logging
 
             builder.AddConfiguration();
 
-            builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<ILoggerProvider, OpenTelemetryLoggerProvider>());
+            builder.Services.TryAddEnumerable(
+                ServiceDescriptor.Singleton<ILoggerProvider, OpenTelemetryLoggerProvider>(
+                    sp => new OpenTelemetryLoggerProvider(sp)));
 
             // Note: This will bind logger options element (eg "Logging:OpenTelemetry") to OpenTelemetryLoggerOptions
             LoggerProviderOptions.RegisterProviderOptions<OpenTelemetryLoggerOptions, OpenTelemetryLoggerProvider>(builder.Services);

test/OpenTelemetry.Tests/Logs/OpenTelemetryLoggerProviderTests.cs

@@ -15,6 +15,8 @@
 // </copyright>
 
 using System.Collections.Generic;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using OpenTelemetry.Exporter;
 using OpenTelemetry.Resources;
@@ -38,6 +40,23 @@ namespace OpenTelemetry.Logs.Tests
             Assert.NotNull(provider.Resource);
         }
 
+        [Fact]
+        public void ResourceDetectionUsingIConfigurationTest()
+        {
+            var services = new ServiceCollection();
+
+            services.AddOptions();
+
+            services.AddSingleton<IConfiguration>(
+                new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string> { ["OTEL_SERVICE_NAME"] = "TestServiceName" }).Build());
+
+            using var serviceProvider = services.BuildServiceProvider();
+
+            using var loggerProvider = new OpenTelemetryLoggerProvider(serviceProvider);
+
+            Assert.Contains(loggerProvider.Resource.Attributes, kvp => kvp.Key == "service.name" && (string)kvp.Value == "TestServiceName");
+        }
+
         [Fact]
         public void ConfigureCtorTests()
         {