Custom Provider (#1)

.github/workflows/release.yml

@@ -8,14 +8,14 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-      - uses: actions/setup-dotnet@v3
+      - uses: actions/setup-dotnet@v4
         with:
           global-json-file: ./global.json
 
       - run: dotnet restore
-      - run: dotnet build --no-restore
+      - run: dotnet build --no-restore --configuration Release
 
       - run: |
           dotnet pack src/CatConsult.AppConfigConfigurationProvider \

.github/workflows/run-tests.yml

@@ -6,9 +6,9 @@ jobs:
   dotnet-test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-      - uses: actions/setup-dotnet@v3
+      - uses: actions/setup-dotnet@v4
         with:
           global-json-file: ./global.json
 

README.md

@@ -1,7 +1,6 @@
 # AWS AppConfig Configuration Provider for .NET
 
-An opinionated [.NET Configuration Provider](https://learn.microsoft.com/en-us/dotnet/core/extensions/configuration-providers)
-for AWS AppConfig that wraps [Amazon.Extensions.Configuration.SystemsManager](https://www.nuget.org/packages/Amazon.Extensions.Configuration.SystemsManager/).
+An opinionated [.NET Configuration Provider](https://learn.microsoft.com/en-us/dotnet/core/extensions/configuration-providers) for AWS AppConfig.
 
 ## Usage
 

src/CatConsult.AppConfigConfigurationProvider/AppConfigConfigurationProvider.cs

@@ -0,0 +1,117 @@
+using Amazon.AppConfigData;
+using Amazon.AppConfigData.Model;
+
+using CatConsult.ConfigurationParsers;
+
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Primitives;
+
+namespace CatConsult.AppConfigConfigurationProvider;
+
+public sealed class AppConfigConfigurationProvider : ConfigurationProvider, IDisposable
+{
+    private const int LockReleaseTimeout = 3_000;
+
+    private readonly IAmazonAppConfigData _client;
+    private readonly AppConfigProfile _profile;
+    private readonly SemaphoreSlim _lock;
+
+    private IDisposable? _reloadChangeToken;
+
+    public AppConfigConfigurationProvider(IAmazonAppConfigData client, AppConfigProfile profile)
+    {
+        _profile = profile;
+        _client = client;
+        _lock = new SemaphoreSlim(1, 1);
+    }
+
+    public AppConfigConfigurationProvider(AppConfigProfile profile) : this(new AmazonAppConfigDataClient(), profile) { }
+
+    private string? ConfigurationToken { get; set; }
+
+    private DateTimeOffset NextPollingTime { get; set; }
+
+    public override void Load()
+    {
+        LoadAsync().GetAwaiter().GetResult();
+
+        if (_profile.ReloadAfter.HasValue)
+        {
+            _reloadChangeToken = ChangeToken.OnChange(
+                () => new CancellationChangeToken(
+                    new CancellationTokenSource(_profile.ReloadAfter.Value).Token
+                ),
+                Load
+            );
+        }
+    }
+
+    private async Task LoadAsync()
+    {
+        if (!await _lock.WaitAsync(LockReleaseTimeout))
+        {
+            return;
+        }
+
+        try
+        {
+            if (DateTimeOffset.UtcNow < NextPollingTime)
+            {
+                return;
+            }
+
+            if (string.IsNullOrEmpty(ConfigurationToken))
+            {
+                await InitializeAppConfigSessionAsync();
+            }
+
+            var request = new GetLatestConfigurationRequest
+            {
+                ConfigurationToken = ConfigurationToken
+            };
+
+            var response = await _client.GetLatestConfigurationAsync(request);
+            ConfigurationToken = response.NextPollConfigurationToken;
+            NextPollingTime = DateTimeOffset.UtcNow.AddSeconds(response.NextPollIntervalInSeconds);
+
+            // If the remote configuration has changed, the API will send back data and we re-parse
+            if (response.ContentLength > 0)
+            {
+                Data = ParseConfig(response.Configuration, response.ContentType);
+            }
+        }
+        finally
+        {
+            _lock.Release();
+        }
+    }
+
+    private async Task InitializeAppConfigSessionAsync()
+    {
+        var session = await _client.StartConfigurationSessionAsync(new StartConfigurationSessionRequest
+        {
+            ApplicationIdentifier = _profile.ApplicationId,
+            EnvironmentIdentifier = _profile.EnvironmentId,
+            ConfigurationProfileIdentifier = _profile.ProfileId,
+        });
+
+        ConfigurationToken = session.InitialConfigurationToken;
+    }
+
+    private static IDictionary<string, string?> ParseConfig(Stream stream, string? contentType)
+    {
+        if (!string.IsNullOrEmpty(contentType))
+        {
+            contentType = contentType.Split(";")[0];
+        }
+
+        return contentType switch
+        {
+            "application/json" => JsonConfigurationParser.Parse(stream),
+            "application/x-yaml" => YamlConfigurationParser.Parse(stream),
+            _ => throw new FormatException($"This configuration provider does not support: {contentType ?? "Unknown"}")
+        };
+    }
+
+    public void Dispose() => _reloadChangeToken?.Dispose();
+}

src/CatConsult.AppConfigConfigurationProvider/AppConfigConfigurationProviderExtensions.cs

@@ -1,37 +1,51 @@
+using Amazon.AppConfigData;
+
 using CatConsult.AppConfigConfigurationProvider.Utilities;
 
 using Microsoft.Extensions.Configuration;
 
 namespace CatConsult.AppConfigConfigurationProvider;
 
+// ReSharper disable UnusedType.Global
+// ReSharper disable UnusedMember.Global
+// ReSharper disable MemberCanBePrivate.Global
 public static class AppConfigConfigurationProviderExtensions
 {
+    public const string DefaultSectionName = "AppConfig";
+
     public static IConfigurationBuilder AddAppConfig(
         this IConfigurationBuilder builder,
-        string sectionName = "AppConfig"
+        string sectionName = DefaultSectionName
     )
     {
-        var options = builder.Build()
-            .GetSection(sectionName)
-            .Get<AppConfigOptions>();
-
-        if (options is null)
+        foreach (var profile in LoadProfiles(builder, sectionName))
         {
-            return builder;
+            builder.Add(new AppConfigConfigurationSource(profile));
         }
 
-        var profiles = options.Profiles.Select(AppConfigProfileParser.Parse);
+        return builder;
+    }
 
-        foreach (var profile in profiles)
+    public static IConfigurationBuilder AddAppConfig(
+        this IConfigurationBuilder builder,
+        IAmazonAppConfigData client,
+        string sectionName = DefaultSectionName
+    )
+    {
+        foreach (var profile in LoadProfiles(builder, sectionName))
         {
-            builder.AddAppConfig(
-                profile.ApplicationId,
-                profile.EnvironmentId,
-                profile.ProfileId,
-                TimeSpan.FromSeconds(profile.ReloadAfter ?? options.Defaults.ReloadAfter)
-            );
+            builder.Add(new AppConfigConfigurationSource(client, profile));
         }
 
         return builder;
     }
+
+    private static IEnumerable<AppConfigProfile> LoadProfiles(IConfigurationBuilder builder, string sectionName)
+    {
+        var options = builder.Build()
+            .GetSection(sectionName)
+            .Get<AppConfigOptions>() ?? new AppConfigOptions();
+
+        return options.Profiles.Select(AppConfigProfileParser.Parse);
+    }
 }

src/CatConsult.AppConfigConfigurationProvider/AppConfigConfigurationSource.cs

@@ -0,0 +1,18 @@
+using Amazon.AppConfigData;
+
+using Microsoft.Extensions.Configuration;
+
+namespace CatConsult.AppConfigConfigurationProvider;
+
+public sealed class AppConfigConfigurationSource : IConfigurationSource
+{
+    private readonly AppConfigConfigurationProvider _provider;
+
+    public AppConfigConfigurationSource(IAmazonAppConfigData client, AppConfigProfile profile) =>
+        _provider = new AppConfigConfigurationProvider(client, profile);
+
+    public AppConfigConfigurationSource(AppConfigProfile profile) =>
+        _provider = new AppConfigConfigurationProvider(profile);
+
+    public IConfigurationProvider Build(IConfigurationBuilder builder) => _provider;
+}

src/CatConsult.AppConfigConfigurationProvider/CatConsult.AppConfigConfigurationProvider.csproj

@@ -12,7 +12,7 @@
     <PackageTags>Configuration</PackageTags>
 
     <Description>
-      An opinionated .NET Configuration Provider for AWS AppConfig that wraps Amazon.Extensions.Configuration.SystemsManager
+      An opinionated .NET Configuration Provider for AWS AppConfig
     </Description>
     <Authors>Derek McKinnon</Authors>
     <Company>Catalyst Consulting Group, Inc.</Company>
@@ -22,7 +22,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Amazon.Extensions.Configuration.SystemsManager" Version="5.1.0" />
+    <PackageReference Include="AWSSDK.AppConfigData" Version="3.7.300.16" />
+    <PackageReference Include="CatConsult.ConfigurationParsers" Version="2.1.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration" Version="6.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="6.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="6.0.0" />