Added support for AppConfig Feature Flag profiles

README.md

@@ -214,6 +214,51 @@ namespace CustomParameterProcessorExample
 }
 ```
 
+### Simple AppConfig FeatureFlag Sample
+```csharp
+//
+// AppConfigFeatureFlag.cs
+//
+public class AppConfigFeatureFlag
+{
+    [JsonPropertyName("enabled")]
+    public bool Enabled { get; set; }
+}
+
+//
+// Program.cs
+//
+
+// Map feature flag configuration 
+builder.Services.Configure<Dictionary<string, AppConfigFeatureFlag>>(builder.Configuration.GetSection("FeatureFlags"));
+
+// Add AppConfig configuration source
+var awsAppConfigClient = new AmazonAppConfigDataClient();
+builder.Configuration
+    .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
+    .AddAppConfig(new AppConfigConfigurationSource()
+    {
+        ApplicationId = "application",
+        EnvironmentId = "Default",
+        ConfigProfileId = "my-appconfig-feature-profile",
+        AwsOptions = new AWSOptions(),
+        ReloadAfter = new TimeSpan(0, 0, 30),
+        WrapperNodeName = "FeatureFlags" // Nest AppConfig FeatureFlag data under this node
+    });
+
+//
+// TestApi.cs
+//
+public class TestApi : ITestApi
+{
+    private readonly IOptionsMonitor<Dictionary<string, AppConfigFeatureFlag>> _FeatureFlags;
+    public TestApi(IOptionsMonitor<Dictionary<string, AppConfigFeatureFlag>> featureFlags)
+    {
+        _FeatureFlags = featureFlags;
+    }
+}
+```
+
 For more complete examples, take a look at sample projects available in [samples directory](https://github.com/aws/aws-dotnet-extensions-configuration/tree/master/samples).
 
 # Configuring Systems Manager Client

src/Amazon.Extensions.Configuration.SystemsManager/AppConfig/AppConfigConfigurationSource.cs

@@ -51,6 +51,11 @@ public class AppConfigConfigurationSource : ISystemsManagerConfigurationSource
 
         /// <inheritdoc />
         public TimeSpan? ReloadAfter { get; set; }
+
+        /// <summary>
+        /// Name of the node to wrap the configuration data in.
+        /// </summary>
+        public string WrapperNodeName { get; set; }
 
         /// <summary>
         /// Indicates to use configured lambda extension HTTP client to retrieve AppConfig data.

src/Amazon.Extensions.Configuration.SystemsManager/AppConfig/AppConfigExtensions.cs

@@ -238,7 +238,8 @@ private static AppConfigConfigurationSource ConfigureSource(
             string configProfileId,
             AWSOptions awsOptions = null,
             bool optional = false,
-            TimeSpan? reloadAfter = null
+            TimeSpan? reloadAfter = null,
+            string wrapperNodeName = null
         )
         {
             return new AppConfigConfigurationSource
@@ -248,7 +249,8 @@ private static AppConfigConfigurationSource ConfigureSource(
                 ConfigProfileId = configProfileId,
                 AwsOptions = awsOptions,
                 Optional = optional,
-                ReloadAfter = reloadAfter
+                ReloadAfter = reloadAfter,
+                WrapperNodeName = wrapperNodeName
             };
         }
     }

src/Amazon.Extensions.Configuration.SystemsManager/AppConfig/AppConfigProcessor.cs

@@ -93,6 +93,19 @@ public async Task<IDictionary<string, string>> GetDataAsync()
                        ?? new Dictionary<string, string>();
             }
         }
+
+        private async Task AddWrapperNodeAsync(Stream configStream, Stream wrappedStream)
+        {
+            string wrappedConfig;
+            using (var reader = new StreamReader(configStream))
+            {
+                wrappedConfig = $"{{\"{Source.WrapperNodeName}\":{await reader.ReadToEndAsync().ConfigureAwait(false)}}}";
+            }
+
+            var wrappedConfigBytes = System.Text.Encoding.UTF8.GetBytes(wrappedConfig);
+            await wrappedStream.WriteAsync(wrappedConfigBytes, 0, wrappedConfigBytes.Length).ConfigureAwait(false);
+            wrappedStream.Position = 0;
+        }
 
         private async Task<IDictionary<string,string>> GetDataFromLambdaExtensionAsync()
         {
@@ -134,7 +147,18 @@ private async Task<IDictionary<string, string>> GetDataFromServiceAsync()
                     // so only attempt to parse the AppConfig response when it is not empty
                     if (response.ContentLength > 0)
                     {
-                        LastConfig = ParseConfig(response.ContentType, response.Configuration);
+                        if (string.IsNullOrWhiteSpace(Source.WrapperNodeName))
+                        {
+                            LastConfig = ParseConfig(response.ContentType, response.Configuration);
+                        }
+                        else
+                        {
+                            using (var wrappedConfiguration = new MemoryStream())
+                            {
+                                await AddWrapperNodeAsync(response.Configuration, wrappedConfiguration).ConfigureAwait(false);
+                                LastConfig = ParseConfig(response.ContentType, wrappedConfiguration);
+                            }
+                        }
                     }
                 }
                 finally

test/Amazon.Extensions.Configuration.SystemsManager.Tests/AppConfigProcessorTests.cs

@@ -0,0 +1,67 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ * 
+ *  http://aws.amazon.com/apache2.0
+ * 
+ * or in the "license" file accompanying this file. This file is distributed
+ * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using Amazon.Extensions.Configuration.SystemsManager.AppConfig;
+using Amazon.Extensions.NETCore.Setup;
+using Xunit;
+
+namespace Amazon.Extensions.Configuration.SystemsManager.Tests
+{
+    public class AppConfigProcessorTests
+    {
+        [Fact]
+        public async Task AddWrapperNode_WithWrapperNodeName_WrapsConfigurationCorrectly()
+        {
+            // Arrange
+            var source = new AppConfigConfigurationSource
+            {
+                ApplicationId = "appId",
+                EnvironmentId = "envId",
+                ConfigProfileId = "profileId",
+                WrapperNodeName = "FeatureFlags",
+                AwsOptions = new AWSOptions()
+            };
+
+            var processor = new AppConfigProcessor(source);
+            var inputJson = "{\"test-flag-1\":{\"enabled\":false},\"test-flag-2\":{\"enabled\":true}}";
+            using var inputStream = new MemoryStream(Encoding.UTF8.GetBytes(inputJson));
+            using var outputStream = new MemoryStream();
+
+            // Act
+            await InvokeAddWrapperNode(processor, inputStream, outputStream);
+
+            // Assert
+            string resultJson;
+            using (var reader = new StreamReader(outputStream))
+            {
+                resultJson = reader.ReadToEnd();
+            }
+
+            var expectedJson = "{\"FeatureFlags\":{\"test-flag-1\":{\"enabled\":false},\"test-flag-2\":{\"enabled\":true}}}";
+            Assert.Equal(expectedJson, resultJson);
+        }
+
+        // Helper method to invoke the private AddWrapperNode method using reflection
+        private async Task InvokeAddWrapperNode(AppConfigProcessor processor, Stream configuration, Stream wrappedConfig)
+        {
+            var method = typeof(AppConfigProcessor).GetMethod("AddWrapperNodeAsync",
+                System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
+            await (Task)method.Invoke(processor, new object[] { configuration, wrappedConfig });
+        }
+    }
+}