Adds default http targeting context accessor

src/Microsoft.FeatureManagement.AspNetCore/DefaultHttpTargetingContextAccessor.cs

@@ -0,0 +1,73 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.AspNetCore.Http;
+using Microsoft.FeatureManagement.FeatureFilters;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+
+namespace Microsoft.FeatureManagement
+{
+    /// <summary>
+    /// Provides a default implementation of <see cref="ITargetingContextAccessor"/> that creates <see cref="TargetingContext"/> using info from the current HTTP request.
+    /// </summary>
+    public sealed class DefaultHttpTargetingContextAccessor : ITargetingContextAccessor
+    {
+        /// <summary>
+        /// The key used to store and retrieve the TargetingContext from the HttpContext items.
+        /// </summary>
+        public const string TargetingContextLookup = $"Microsoft.FeatureManagement.TargetingContext";
+
+        private readonly IHttpContextAccessor _httpContextAccessor;
+
+        /// <summary>
+        /// Creates an instance of the DefaultHttpTargetingContextAccessor
+        /// </summary>
+        public DefaultHttpTargetingContextAccessor(IHttpContextAccessor httpContextAccessor)
+        {
+            _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
+        }
+
+        /// <summary>
+        /// Gets <see cref="TargetingContext"/> from the current HTTP request.
+        /// </summary>
+        public ValueTask<TargetingContext> GetContextAsync()
+        {
+            HttpContext httpContext = _httpContextAccessor.HttpContext;
+
+            //
+            // Try cache lookup
+            if (httpContext.Items.TryGetValue(TargetingContextLookup, out object value))
+            {
+                return new ValueTask<TargetingContext>((TargetingContext)value);
+            }
+
+            //
+            // Treat user identity name as user id
+            ClaimsPrincipal user = httpContext.User;
+
+            string userId = user?.Identity?.Name;
+
+            //
+            // Treat claims of type Role as groups
+            IEnumerable<string> groups = httpContext.User.Claims
+                .Where(c => c.Type == ClaimTypes.Role)
+                .Select(c => c.Value);
+
+            TargetingContext targetingContext = new TargetingContext
+            {
+                UserId = userId,
+                Groups = groups
+            };
+
+            //
+            // Cache for subsequent lookup
+            httpContext.Items[TargetingContextLookup] = targetingContext;
+
+            return new ValueTask<TargetingContext>(targetingContext);
+        }
+    }
+}

src/Microsoft.FeatureManagement.AspNetCore/FeatureManagementBuilderExtensions.cs

@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.FeatureManagement.FeatureFilters;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.FeatureManagement
+{
+    /// <summary>
+    /// Extensions used to add feature management functionality.
+    /// </summary>
+    public static class FeatureManagementBuilderExtensions
+    {
+        /// <summary>
+        /// Adds the <see cref="DefaultHttpTargetingContextAccessor"/> to be used for targeting and registers the targeting filter to the feature management system.
+        /// </summary>
+        /// <param name="builder">The <see cref="IFeatureManagementBuilder"/> used to customize feature management functionality.</param>
+        /// <returns>A <see cref="IFeatureManagementBuilder"/> that can be used to customize feature management functionality.</returns>
+        public static IFeatureManagementBuilder WithTargeting(this IFeatureManagementBuilder builder)
+        {
+            //
+            // Register the targeting context accessor with the same lifetime as the feature manager
+            if (builder.Services.Any(descriptor => descriptor.ServiceType == typeof(IFeatureManager) && descriptor.Lifetime == ServiceLifetime.Scoped))
+            {
+                builder.Services.TryAddScoped<ITargetingContextAccessor, DefaultHttpTargetingContextAccessor>();
+            }
+            else
+            {
+                builder.Services.TryAddSingleton<ITargetingContextAccessor, DefaultHttpTargetingContextAccessor>();
+            }
+
+            builder.AddFeatureFilter<TargetingFilter>();
+
+            return builder;
+        }
+    }
+}

src/Microsoft.FeatureManagement.AspNetCore/TargetingHttpContextMiddleware.cs

@@ -18,8 +18,6 @@ public class TargetingHttpContextMiddleware
         private readonly RequestDelegate _next;
         private readonly ILogger _logger;
 
-        private const string TargetingIdKey = $"Microsoft.FeatureManagement.TargetingId";
-
         /// <summary>
         /// Creates an instance of the TargetingHttpContextMiddleware
         /// </summary>
@@ -48,9 +46,9 @@ public async Task InvokeAsync(HttpContext context, ITargetingContextAccessor tar
 
             TargetingContext targetingContext = await targetingContextAccessor.GetContextAsync().ConfigureAwait(false);
 
-            if (targetingContext != null)
+            if (targetingContext != null && !context.Items.ContainsKey(DefaultHttpTargetingContextAccessor.TargetingContextLookup))
             {
-                context.Items[TargetingIdKey] = targetingContext.UserId;
+                context.Items[DefaultHttpTargetingContextAccessor.TargetingContextLookup] = targetingContext;
             }
             else
             {

src/Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore/Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore.csproj

@@ -38,6 +38,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Microsoft.FeatureManagement\Microsoft.FeatureManagement.csproj" />
+    <ProjectReference Include="..\Microsoft.FeatureManagement.AspNetCore\Microsoft.FeatureManagement.AspNetCore.csproj" />
     <ProjectReference Include="..\Microsoft.FeatureManagement.Telemetry.ApplicationInsights\Microsoft.FeatureManagement.Telemetry.ApplicationInsights.csproj" />
   </ItemGroup>
 

src/Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore/TargetingTelemetryInitializer.cs

@@ -6,6 +6,7 @@
 using Microsoft.ApplicationInsights.Channel;
 using Microsoft.ApplicationInsights.DataContracts;
 using Microsoft.AspNetCore.Http;
+using Microsoft.FeatureManagement.FeatureFilters;
 
 namespace Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore
 {
@@ -14,8 +15,6 @@ namespace Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore
     /// </summary>
     public class TargetingTelemetryInitializer : TelemetryInitializerBase
     {
-        private const string TargetingIdKey = $"Microsoft.FeatureManagement.TargetingId";
-
         /// <summary>
         /// Creates an instance of the TargetingTelemetryInitializer
         /// </summary>
@@ -37,27 +36,23 @@ protected override void OnInitializeTelemetry(HttpContext httpContext, RequestTe
                 throw new ArgumentNullException(nameof(telemetry));
             }
 
+            if (telemetry is not ISupportProperties telemetryWithSupportProperties)
+            {
+                return;
+            }
+
             if (httpContext == null)
             {
                 throw new ArgumentNullException(nameof(httpContext));
             }
 
-            // Extract the targeting id from the http context
-            string targetingId = null;
+            //
+            // Extract the targeting info from the http context
+            TargetingContext targetingContext = httpContext.Items[DefaultHttpTargetingContextAccessor.TargetingContextLookup] as TargetingContext;
 
-            if (httpContext.Items.TryGetValue(TargetingIdKey, out object value))
-            {
-                targetingId = value?.ToString();
-            }
+            string targetingId = targetingContext?.UserId ?? string.Empty;
 
-            if (!string.IsNullOrEmpty(targetingId))
-            {
-                // Telemetry.Properties is deprecated in favor of ISupportProperties
-                if (telemetry is ISupportProperties telemetryWithSupportProperties)
-                {
-                    telemetryWithSupportProperties.Properties["TargetingId"] = targetingId;
-                }
-            }
+            telemetryWithSupportProperties.Properties["TargetingId"] = targetingId;
         }
     }
 }

src/Microsoft.FeatureManagement.Telemetry.ApplicationInsights/ApplicationInsightsTelemetryPublisher.cs

@@ -44,7 +44,7 @@ public ValueTask PublishEvent(EvaluationEvent evaluationEvent, CancellationToken
 
             if (evaluationEvent.TargetingContext != null)
             {
-                properties["TargetingId"] = evaluationEvent.TargetingContext.UserId;
+                properties["TargetingId"] = evaluationEvent.TargetingContext.UserId ?? string.Empty;
             }
 
             if (evaluationEvent.VariantAssignmentReason != VariantAssignmentReason.None)