Add Microsoft.Extensions.Configuration.AppConfiguration package by m-nash · Pull Request #56619 · Azure/azure-sdk-for-net

m-nash · 2026-02-28T01:21:58Z

Description

Implements IConfigurationSource for Azure App Configuration using the System.ClientModel configuration pattern (ConfigurationClientSettings) and Azure Identity (WithAzureCredential).

Public API

The public API surface is minimal — two AddAppConfigurations extension methods on IConfigurationBuilder:

AddAppConfigurations(string sectionName) — loads settings using a ConfigurationClient configured from the named configuration section
AddAppConfigurations(string sectionName, Action<ConfigurationClientSettings> configure) — same, with an optional settings override

Design Notes

Unlike the Key Vault configuration provider, App Configuration keys use native : separators for hierarchical configuration (e.g., MyClient:Options:Retry:MaxRetries) since the service supports them directly. No -- to : translation is needed.

Internal Implementation

The internal implementation (provider, source, setting manager) mirrors the existing Microsoft.Extensions.Configuration.KeyVault package pattern with full test parity (17 tests).

Changes

New package: sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/
Added to sdk/appconfiguration/ci.yml

Fixes #55509

Implements IConfigurationSource for Azure App Configuration using the System.ClientModel configuration pattern (ConfigurationClientSettings) and Azure Identity. Keys use native colon (:) separators since App Configuration supports them directly (unlike Key Vault secrets). Fixes #55509 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-02-28T01:44:05Z

API Change Check

APIView identified API level changes in this PR and created the following API reviews

Microsoft.Extensions.Configuration.AppConfiguration

Copilot

Pull request overview

This PR introduces a new Microsoft.Extensions.Configuration.AppConfiguration package under sdk/appconfiguration/ that provides IConfigurationBuilder extension methods to load configuration values from Azure App Configuration using the System.ClientModel configuration pattern (ConfigurationClientSettings) and Azure Identity configuration binding.

Changes:

Added a new extension package implementing an IConfigurationSource/IConfigurationProvider for Azure App Configuration.
Added a full NUnit test suite (including snippets) and API surface files for the new package.
Wired the new package into sdk/appconfiguration/ci.yml and documentation tooling configuration.

Reviewed changes

Copilot reviewed 21 out of 21 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
sdk/appconfiguration/ci.yml	Adds the new artifact to the App Configuration service pipeline.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/Snippets.cs	Adds usage snippet for `AddAppConfigurations`.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/MyClientSettings.cs	Test-only `ClientSettings` type for snippet/DI tests.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/MyClient.cs	Test-only client type for snippet/DI tests.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/Microsoft.Extensions.Configuration.AppConfiguration.Tests.csproj	Introduces test project for the new package.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/ConfigurationProviderExtensions.cs	Adds test helper extension for reading provider values.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/tests/AppConfigurationTests.cs	Adds provider behavior tests (load/filter/reload/custom mapping/custom data).
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/Properties/AssemblyInfo.cs	Adds InternalsVisibleTo for tests/proxy generation.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/Microsoft.Extensions.Configuration.AppConfiguration.csproj	Defines the new package project and dependencies.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/AppConfigurationSource.cs	Implements `IConfigurationSource` to create the provider.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/AppConfigurationSettingManager.cs	Adds a manager abstraction for filtering/mapping/settings-to-data conversion.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/AppConfigurationProvider.cs	Implements the configuration provider, including background polling reload.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/AppConfigurationOptions.cs	Provides internal options for reload interval and selector/manager.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/src/AppConfigurationExtensions.cs	Adds the public `AddAppConfigurations` extension methods.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/api/Microsoft.Extensions.Configuration.AppConfiguration.netstandard2.0.cs	Adds API surface snapshot for netstandard2.0.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/api/Microsoft.Extensions.Configuration.AppConfiguration.net8.0.cs	Adds API surface snapshot for net8.0.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/api/Microsoft.Extensions.Configuration.AppConfiguration.net10.0.cs	Adds API surface snapshot for net10.0.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/README.md	Adds package README with getting started + example.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/Directory.Build.props	Marks the package directory as a client library for build tooling.
sdk/appconfiguration/Microsoft.Extensions.Configuration.AppConfiguration/CHANGELOG.md	Adds initial Unreleased changelog entry for 1.0.0-beta.1.
eng/.docsettings.yml	Adds the new README to the docsettings allowlist/known issues list.

Copilot · 2026-03-02T18:03:26Z

+            bool hasChanges = oldLoadedSettings == null
+                || newLoadedSettings.Count != (oldLoadedSettings.Count + newLoadedSettings.Count - oldLoadedSettings.Count)
+                || oldLoadedSettings.Any();


The hasChanges calculation is incorrect: (oldLoadedSettings.Count + newLoadedSettings.Count - oldLoadedSettings.Count) always simplifies to newLoadedSettings.Count, so this count comparison can never detect added/removed keys. This can prevent Data from being refreshed (and OnReload() raised) when settings are added/removed but existing keys are up-to-date. Track the original old count before removals and compare it to newLoadedSettings.Count, and/or explicitly detect additions/removals/updates.

Copilot · 2026-03-02T18:03:27Z

+            var newLoadedSettings = new Dictionary<string, ConfigurationSetting>(StringComparer.OrdinalIgnoreCase);
+            var oldLoadedSettings = Interlocked.Exchange(ref _loadedSettings, null);
+
+            await foreach (var setting in _client.GetConfigurationSettingsAsync(_selector).ConfigureAwait(false))


The async settings query doesn't pass _cancellationToken.Token to GetConfigurationSettingsAsync(...), so disposal won't cancel an in-progress refresh. Pass the token to the client call so the background polling loop can shut down promptly.

Suggested change

await foreach (var setting in _client.GetConfigurationSettingsAsync(_selector).ConfigureAwait(false))

await foreach (var setting in _client.GetConfigurationSettingsAsync(_selector, _cancellationToken.Token).ConfigureAwait(false))

Copilot · 2026-03-02T18:03:27Z

+using System;
+using System.Diagnostics.CodeAnalysis;
+using Azure.Data.AppConfiguration;
+using Azure.Identity;


using Azure.Identity; is unused in this file. Since warnings are treated as errors, this will fail the build; remove the unused using (the package reference can remain).

Suggested change

using Azure.Identity;

Copilot · 2026-03-02T18:03:27Z

+            while (!_cancellationToken.IsCancellationRequested)
+            {
+                await WaitForReload().ConfigureAwait(false);
+                try
+                {
+                    await LoadAsync().ConfigureAwait(false);
+                }
+                catch (Exception)
+                {
+                    // Ignore
+                }


WaitForReload() uses Task.Delay(..., _cancellationToken.Token), which will throw OperationCanceledException when disposed/canceled. That exception isn't caught in PollForSettingChangesAsync, so the background polling task can fault on disposal (potentially surfacing as an unobserved task exception). Catch OperationCanceledException around the delay (or in the loop) and exit cleanly when cancellation is requested.

Copilot · 2026-03-02T18:03:28Z

+        /// </summary>
+        public override void Load()
+        {
+            var settingPages = _client.GetConfigurationSettings(_selector);


The provider creates a _cancellationToken for shutdown, but the synchronous settings query doesn't pass it to GetConfigurationSettings. This means an in-flight load won't be cancelable during Dispose(). Consider passing _cancellationToken.Token to GetConfigurationSettings(_selector, ...) to honor cancellation.

Suggested change

var settingPages = _client.GetConfigurationSettings(_selector);

var settingPages = _client.GetConfigurationSettings(_selector, _cancellationToken.Token);

Copilot · 2026-03-02T18:03:28Z

+
+using System;
+using System.Collections.Generic;
+using System.Linq;


using System.Linq; is unused in this file. The repo treats warnings as errors, so this will break the build; remove the unused using (or use it).

Suggested change

using System.Linq;

Copilot · 2026-03-02T18:03:28Z

+    /// Default implementation of <see cref="AppConfigurationSettingManager"/> that loads all settings
+    /// and replaces '--' with ':' in key names.


The XML summary says the default manager "replaces '--' with ':' in key names", but GetKey currently returns setting.Key unchanged. Update the comment to match the actual behavior (or implement the replacement if that's intended).

Suggested change

/// Default implementation of <see cref="AppConfigurationSettingManager"/> that loads all settings

/// and replaces '--' with ':' in key names.

/// Default implementation of <see cref="AppConfigurationSettingManager"/> that loads all settings.

Copilot · 2026-03-02T18:03:29Z

+using System;
+using System.ClientModel;
+using System.Diagnostics.CodeAnalysis;


using System; is unused in this snippet. With warnings treated as errors, the test project will fail to compile; remove the unused using.

Copilot · 2026-03-02T18:03:29Z

+            bool hasChanges = oldLoadedSettings == null
+                || newLoadedSettings.Count != (oldLoadedSettings.Count + newLoadedSettings.Count - oldLoadedSettings.Count)
+                || oldLoadedSettings.Any();
+


Same issue as the sync Load(): this hasChanges count comparison simplifies to comparing newLoadedSettings.Count to itself, so it can never detect additions/removals when oldLoadedSettings has been drained of up-to-date keys. Fix the change-detection logic here as well (e.g., keep the original old count before removals and compare to the new count).

zhiyuanliang-ms · 2026-03-03T15:50:57Z

Hey, @m-nash

There is already the Microsoft.Extensions.Configuration.AzureAppConfiguration nuget package.

Here is the repo: https://github.com/Azure/AppConfiguration-DotnetProvider

m-nash · 2026-03-04T23:11:56Z

Closing in favor of Azure/AppConfiguration-DotnetProvider#728 which implements this directly in the existing provider package.

github-actions Bot added the App Configuration Azure.ApplicationModel.Configuration label Feb 28, 2026

m-nash marked this pull request as ready for review March 2, 2026 17:55

Copilot AI review requested due to automatic review settings March 2, 2026 17:55

m-nash requested review from avanigupta, benbp, hallipr, linglingye001, weshaggard and zhiyuanliang-ms as code owners March 2, 2026 17:55

m-nash marked this pull request as draft March 2, 2026 17:55

m-nash marked this pull request as ready for review March 2, 2026 17:55

m-nash marked this pull request as draft March 2, 2026 17:55

Copilot started reviewing on behalf of m-nash March 2, 2026 17:56 View session

Copilot AI reviewed Mar 2, 2026

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m-nash mentioned this pull request Mar 4, 2026

Add AddAppConfigurations extension for config-section-based client construction Azure/AppConfiguration-DotnetProvider#728

Open

m-nash closed this Mar 4, 2026

	await foreach (var setting in _client.GetConfigurationSettingsAsync(_selector).ConfigureAwait(false))
	await foreach (var setting in _client.GetConfigurationSettingsAsync(_selector, _cancellationToken.Token).ConfigureAwait(false))

	var settingPages = _client.GetConfigurationSettings(_selector);
	var settingPages = _client.GetConfigurationSettings(_selector, _cancellationToken.Token);

		/// Default implementation of <see cref="AppConfigurationSettingManager"/> that loads all settings
		/// and replaces '--' with ':' in key names.

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m-nash commented Feb 28, 2026

Description

Public API

Design Notes

Internal Implementation

Changes

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zhiyuanliang-ms commented Mar 3, 2026 •

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