[Instrumentation.EventCounters] DI support for configuring

src/OpenTelemetry.Instrumentation.EventCounters/.publicApi/PublicAPI.Unshipped.txt

@@ -4,4 +4,6 @@ OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions.
 OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions.RefreshIntervalSecs.get -> int
 OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions.RefreshIntervalSecs.set -> void
 OpenTelemetry.Metrics.MeterProviderBuilderExtensions
-static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddEventCountersInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder! builder, System.Action<OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions!>? configure = null) -> OpenTelemetry.Metrics.MeterProviderBuilder!
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddEventCountersInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder! builder) -> OpenTelemetry.Metrics.MeterProviderBuilder!
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddEventCountersInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder! builder, string? name, System.Action<OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions!>? configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!
+static OpenTelemetry.Metrics.MeterProviderBuilderExtensions.AddEventCountersInstrumentation(this OpenTelemetry.Metrics.MeterProviderBuilder! builder, System.Action<OpenTelemetry.Instrumentation.EventCounters.EventCountersInstrumentationOptions!>! configure) -> OpenTelemetry.Metrics.MeterProviderBuilder!

src/OpenTelemetry.Instrumentation.EventCounters/CHANGELOG.md

@@ -2,6 +2,16 @@
 
 ## Unreleased
 
+* Added support for configuring `EventCounters` instrumentation via dependency
+  injection APIs: You can now enable `EventCounters` instrumentation and
+  configure options using the `AddEventCountersInstrumentation` method alongside
+  `IDeferredMeterProviderBuilder`. Configuration can be provided through
+  an `IConfigurationSection`, allowing easier setup through app configuration.
+  New environment variables introduced for further customization:
+  `OTEL_DOTNET_EVENTCOUNTERS_REFRESH_INTERVAL_SECS`: Specifies the refresh interval.
+  `OTEL_DOTNET_EVENTCOUNTERS_SOURCES`: Defines the sources.
+  ([#2078](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/2078))
+
 * `Meter.Version` is set to NuGet package version.
   ([#1624](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/1624))
 

src/OpenTelemetry.Instrumentation.EventCounters/EventCountersInstrumentationEventSource.cs

@@ -2,17 +2,23 @@
 // SPDX-License-Identifier: Apache-2.0
 
 using System.Diagnostics.Tracing;
+using Microsoft.Extensions.Configuration;
 
 namespace OpenTelemetry.Instrumentation.EventCounters;
 
 /// <summary>
 /// EventSource events emitted from the project.
 /// </summary>
 [EventSource(Name = "OpenTelemetry-Instrumentation-EventCounters")]
-internal sealed class EventCountersInstrumentationEventSource : EventSource
+internal sealed class EventCountersInstrumentationEventSource : EventSource, IConfigurationExtensionsLogger
 {
     public static readonly EventCountersInstrumentationEventSource Log = new();
 
+    void IConfigurationExtensionsLogger.LogInvalidConfigurationValue(string key, string value)
+    {
+        this.InvalidConfigurationValue(key, value);
+    }
+
     [Event(1, Level = EventLevel.Warning, Message = "Error while writing event from source: {0} - {1}.")]
     internal void ErrorWhileWritingEvent(string eventSourceName, string exceptionMessage)
     {
@@ -42,4 +48,10 @@ internal void IgnoreNonEventCountersName(string eventSourceName)
     {
         this.WriteEvent(5, eventSourceName);
     }
+
+    [Event(6, Level = EventLevel.Warning, Message = "Configuration key '{0}' has an invalid value: '{1}'")]
+    internal void InvalidConfigurationValue(string key, string value)
+    {
+        this.WriteEvent(6, key, value);
+    }
 }

src/OpenTelemetry.Instrumentation.EventCounters/EventCountersInstrumentationOptions.cs

@@ -1,14 +1,47 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+using System.Diagnostics;
+using Microsoft.Extensions.Configuration;
+
 namespace OpenTelemetry.Instrumentation.EventCounters;
 
 /// <summary>
 /// EventCounters Instrumentation Options.
 /// </summary>
 public class EventCountersInstrumentationOptions
 {
-    internal readonly HashSet<string> EventSourceNames = new();
+    internal readonly HashSet<string> EventSourceNames = [];
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="EventCountersInstrumentationOptions"/> class.
+    /// </summary>
+    public EventCountersInstrumentationOptions()
+        : this(new ConfigurationBuilder().AddEnvironmentVariables().Build())
+    {
+    }
+
+    internal EventCountersInstrumentationOptions(IConfiguration configuration)
+    {
+        Debug.Assert(configuration != null, "configuration was null");
+
+        if (configuration!.TryGetIntValue(
+                EventCountersInstrumentationEventSource.Log,
+                "OTEL_DOTNET_EVENTCOUNTERS_REFRESH_INTERVAL_SECS",
+                out var refreshIntervalSecs))
+        {
+            this.RefreshIntervalSecs = refreshIntervalSecs;
+        }
+
+        if (configuration!.TryGetValue<string[]>(
+                EventCountersInstrumentationEventSource.Log,
+                "OTEL_DOTNET_EVENTCOUNTERS_SOURCES",
+                this.TrySplitString,
+                out var eventSourceNames) && eventSourceNames != null)
+        {
+            this.AddEventSources(eventSourceNames);
+        }
+    }
 
     /// <summary>
     /// Gets or sets the subscription interval in seconds for reading values
@@ -39,4 +72,22 @@ internal bool ShouldListenToSource(string eventSourceName)
     {
         return this.EventSourceNames.Contains(eventSourceName);
     }
+
+    /// <summary>
+    /// Tries to split the provided string using a comma as the separator.
+    /// </summary>
+    /// <param name="value">The string to split.</param>
+    /// <param name="parsedValue">The array of strings after the split.</param>
+    /// <returns><c>true</c> if the split was successful; otherwise, <c>false</c>.</returns>
+    private bool TrySplitString(string value, out string[]? parsedValue)
+    {
+        if (!string.IsNullOrEmpty(value))
+        {
+            parsedValue = value.Split(',');
+            return true;
+        }
+
+        parsedValue = null;
+        return false;
+    }
 }

src/OpenTelemetry.Instrumentation.EventCounters/MeterProviderBuilderExtensions.cs

@@ -1,6 +1,8 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 using OpenTelemetry.Instrumentation.EventCounters;
 using OpenTelemetry.Internal;
 
@@ -15,18 +17,60 @@ public static class MeterProviderBuilderExtensions
     /// Enables EventCounter instrumentation.
     /// </summary>
     /// <param name="builder"><see cref="MeterProviderBuilder"/> being configured.</param>
+    /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
+    public static MeterProviderBuilder AddEventCountersInstrumentation(this MeterProviderBuilder builder)
+        => AddEventCountersInstrumentation(builder, name: null, configure: null);
+
+    /// <summary>
+    /// Enables EventCounter instrumentation.
+    /// </summary>
+    /// <param name="builder"><see cref="MeterProviderBuilder"/> being configured.</param>
+    /// <param name="configure">EventCounters instrumentation options.</param>
+    /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
+    public static MeterProviderBuilder AddEventCountersInstrumentation(
+        this MeterProviderBuilder builder,
+        Action<EventCountersInstrumentationOptions> configure)
+        => AddEventCountersInstrumentation(builder, name: null, configure: configure);
+
+    /// <summary>
+    /// Enables EventCounter instrumentation.
+    /// </summary>
+    /// <param name="builder"><see cref="MeterProviderBuilder"/> being configured.</param>
+    /// <param name="name">The name of the instrumentation.</param>
     /// <param name="configure">EventCounters instrumentation options.</param>
     /// <returns>The instance of <see cref="MeterProviderBuilder"/> to chain the calls.</returns>
     public static MeterProviderBuilder AddEventCountersInstrumentation(
         this MeterProviderBuilder builder,
-        Action<EventCountersInstrumentationOptions>? configure = null)
+        string? name,
+        Action<EventCountersInstrumentationOptions>? configure)
     {
         Guard.ThrowIfNull(builder);
 
+        name ??= Options.DefaultName;
+
         var options = new EventCountersInstrumentationOptions();
         configure?.Invoke(options);
 
-        builder.AddMeter(EventCountersMetrics.MeterInstance.Name);
-        return builder.AddInstrumentation(() => new EventCountersMetrics(options));
+        builder.ConfigureServices(services =>
+        {
+            if (configure != null)
+            {
+                services.Configure(name, configure);
+            }
+        });
+
+        if (builder is IDeferredMeterProviderBuilder deferredMeterProviderBuilder)
+        {
+            deferredMeterProviderBuilder.Configure((sp, builder) =>
+            {
+                builder.AddMeter(EventCountersMetrics.MeterInstance.Name);
+            });
+        }
+
+        return builder.AddInstrumentation(sp =>
+        {
+            var options = sp.GetRequiredService<IOptionsMonitor<EventCountersInstrumentationOptions>>().Get(name);
+            return new EventCountersMetrics(options);
+        });
     }
 }

src/OpenTelemetry.Instrumentation.EventCounters/OpenTelemetry.Instrumentation.EventCounters.csproj

@@ -14,11 +14,15 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="OpenTelemetry.Api" Version="$(OpenTelemetryCoreLatestVersion)" />
+    <PackageReference Include="Microsoft.Extensions.Configuration" Version="$(MicrosoftExtensionsConfigurationPkgVer)" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="$(MicrosoftExtensionsOptionsPkgVer)" />
+    <PackageReference Include="OpenTelemetry.Api.ProviderBuilderExtensions" Version="$(OpenTelemetryCoreLatestVersion)" />
   </ItemGroup>
 
   <ItemGroup>
     <Compile Include="$(RepoRoot)\src\Shared\AssemblyVersionExtensions.cs" Link="Includes\AssemblyVersionExtensions.cs" />
+    <Compile Include="$(RepoRoot)\src\Shared\Configuration\*.cs" Link="Includes\Configuration\%(Filename).cs" />
+    <Compile Include="$(RepoRoot)\src\Shared\EnvironmentVariables\*.cs" Link="Includes\EnvironmentVariables\%(Filename).cs" />
     <Compile Include="$(RepoRoot)\src\Shared\Guard.cs" Link="Includes\Guard.cs" />
   </ItemGroup>
 

src/OpenTelemetry.Instrumentation.EventCounters/README.md

@@ -1,9 +1,9 @@
 # EventCounters Instrumentation for OpenTelemetry .NET
 
-| Status        |           |
-| ------------- |-----------|
-| Stability     |  [Alpha](../../README.md#alpha)|
-| Code Owners   |  [@hananiel](https://github.com/hananiel), [@mic-max](https://github.com/mic-max)|
+| Status      |                                                                                  |
+| ----------- | -------------------------------------------------------------------------------- |
+| Stability   | [Alpha](../../README.md#alpha)                                                   |
+| Code Owners | [@hananiel](https://github.com/hananiel), [@mic-max](https://github.com/mic-max) |
 
 [![NuGet version badge](https://img.shields.io/nuget/v/OpenTelemetry.Instrumentation.EventCounters)](https://www.nuget.org/packages/OpenTelemetry.Instrumentation.EventCounters)
 [![NuGet download count badge](https://img.shields.io/nuget/dt/OpenTelemetry.Instrumentation.EventCounters)](https://www.nuget.org/packages/OpenTelemetry.Instrumentation.EventCounters)
@@ -32,6 +32,8 @@ dotnet add package OpenTelemetry.Instrumentation.EventCounters --prerelease
 
 ### Step 2: Enable EventCounters Instrumentation
 
+#### Using Direct Configuration
+
 EventCounters instrumentation should be enabled at application startup using the
 `AddEventCountersInstrumentation` extension on the `MeterProviderBuilder`:
 
@@ -50,6 +52,53 @@ requires adding the package
 [`OpenTelemetry.Exporter.Prometheus`](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/src/OpenTelemetry.Exporter.Prometheus.HttpListener/README.md)
 to the application.
 
+#### Using Dependency Injection (DI)
+
+To enable EventCounters instrumentation via DI, configure it as follows:
+
+```csharp
+public void ConfigureServices(IServiceCollection services)
+{
+    services.AddOpenTelemetry().WithMetrics(builder =>
+    {
+        builder.AddEventCountersInstrumentation(options =>
+        {
+            options.RefreshIntervalSecs = 1;
+            options.AddEventSources("MyEventSource");
+        })
+        .AddConsoleExporter();
+    });
+}
+```
+
+This method allows providing options via `IConfigurationSection`
+and integrates seamlessly with DI-based setups.
+
+Alternatively, you can configure the EventCounters instrumentation using settings
+from an IConfigurationSection. This allows you to integrate configuration with
+your app's settings (e.g., appsettings.json or environment variables).
+
+Example using IConfigurationSection:
+
+```csharp
+public void ConfigureServices(IServiceCollection services)
+{
+    services.AddOpenTelemetryMetrics((builder, config) =>
+    {
+        var eventCountersSection = config.GetSection("EventCountersOptions");
+        builder.AddEventCountersInstrumentation(eventCountersSection);
+    });
+}
+```
+
+This method allows seamless integration with DI-based setups and leverages
+configuration files or environment variables:
+
+| Parameter                                         | Type                 | Description                                        | Example                         |
+| ------------------------------------------------- | -------------------- | -------------------------------------------------- | ------------------------------- |
+| `OTEL_DOTNET_EVENTCOUNTERS_REFRESH_INTERVAL_SECS` | Number               | Specifies the refresh interval for event counters. | 1                               |
+| `OTEL_DOTNET_EVENTCOUNTERS_SOURCES`               | Comma-separated list | Defines the sources for event counters.            | "MyEventSource1,MyEventSource2" |
+
 ### Step 3: Create EventCounters
 
 Learn about [EventCounters in

src/Shared/Options/SingletonOptionsManager.cs

@@ -12,7 +12,9 @@ namespace Microsoft.Extensions.Options;
 #if NET
 internal sealed class SingletonOptionsManager<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)] TOptions> : IOptionsMonitor<TOptions>, IOptionsSnapshot<TOptions>
 #else
+#pragma warning disable CA1812 // Is an internal class that is apparently never instantiated
 internal sealed class SingletonOptionsManager<TOptions> : IOptionsMonitor<TOptions>, IOptionsSnapshot<TOptions>
+#pragma warning restore CA1812 // Is an internal class that is apparently never instantiated
 #endif
     where TOptions : class
 {