Adding 'RateLimiting' example to '.Sample'

Author: futurum-dev

README.md

@@ -527,6 +527,7 @@ There are examples showing the following:
 - [x] File(s) upload with Payload
 - [x] File download
 - [x] OpenApi version support
+- [x] RateLimiting
 - [x] Security with a basic JWT example on a specific WebApiEndpoint
 - [x] Validation - DataAnnotations and FluentValidation and both combined
 - [x] Weather Forecast
@@ -556,12 +557,12 @@ This is used to configure *ApiVersioning* and *ApiExplorer*.
 
 There is an overload of *AddWebApiEndpoints* that takes a generic type of *IWebApiVersionConfigurationService*.
 ```csharp
-builder.Services.AddWebApiEndpoints<CustomWebApiVersionConfigurationService>(
+builder.Services.AddWebApiEndpoints<CustomWebApiVersionConfigurationService>();
 ```
 
 Use this instead
 ```csharp
-builder.Services.AddWebApiEndpoints(
+builder.Services.AddWebApiEndpoints();
 ```
 
 ### IWebApiEndpointMetadataStrategy

docs/Futurum.WebApiEndpoint.Micro.Sample-openapi.png

@@ -0,0 +1,22 @@
+namespace Futurum.WebApiEndpoint.Micro.Sample.Features;
+
+[WebApiEndpoint("rate-limiting")]
+public class RateLimitingWebApiEndpoint : IWebApiEndpoint
+{
+    public void Configure(RouteGroupBuilder groupBuilder, WebApiEndpointVersion webApiEndpointVersion)
+    {
+        groupBuilder.RequireRateLimiting(RateLimiting.SlidingWindow.PolicyName);
+    }
+
+    public void Register(IEndpointRouteBuilder builder)
+    {
+        builder.MapGet("/", GetHandler);
+    }
+
+    private static Ok<DataCollectionDto<FeatureDto>> GetHandler(HttpContext context) =>
+        Enumerable.Range(0, 10)
+                  .Select(i => new Feature($"Name - {i}"))
+                  .Select(FeatureMapper.Map)
+                  .ToDataCollectionDto()
+                  .ToOk();
+}

sample/Futurum.WebApiEndpoint.Micro.Sample/Features/RateLimitingWebApiEndpoint.cs

@@ -15,6 +15,7 @@
         <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="7.0.4" />
         <PackageReference Include="Microsoft.Data.Sqlite" Version="7.0.4" />
         <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
+        <PackageReference Include="System.Threading.RateLimiting" Version="7.0.0" />
     </ItemGroup>
 
     <ItemGroup>

sample/Futurum.WebApiEndpoint.Micro.Sample/Futurum.WebApiEndpoint.Micro.Sample.csproj

@@ -11,6 +11,8 @@
 
 builder.AddAuthentication();
 
+builder.Services.AddRateLimiter(RateLimiting.SlidingWindow.Options);
+
 builder.Services
        .AddWebApiEndpoints(new WebApiEndpointConfiguration(WebApiEndpointVersions.V1_0)
        {
@@ -34,6 +36,8 @@
 
 var app = builder.Build();
 
+app.UseRateLimiter();
+
 app.UseWebApiEndpoints();
 
 app.UseExceptionHandler();

sample/Futurum.WebApiEndpoint.Micro.Sample/Program.cs

@@ -0,0 +1,46 @@
+using System.Net;
+using System.Threading.RateLimiting;
+
+using Microsoft.AspNetCore.RateLimiting;
+
+namespace Futurum.WebApiEndpoint.Micro.Sample;
+
+public static class RateLimiting
+{
+    public static class SlidingWindow
+    {
+        public const string PolicyName = "SlidingWindowPolicy";
+
+        public static readonly Action<RateLimiterOptions> Options = options =>
+        {
+            options.AddSlidingWindowLimiter(PolicyName,
+                                            slidingWindowRateLimiterOptions =>
+                                            {
+                                                slidingWindowRateLimiterOptions.PermitLimit = 2;
+                                                slidingWindowRateLimiterOptions.Window = TimeSpan.FromSeconds(5);
+                                                slidingWindowRateLimiterOptions.SegmentsPerWindow = 2;
+                                                slidingWindowRateLimiterOptions.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
+                                                slidingWindowRateLimiterOptions.QueueLimit = 2;
+                                            });
+
+            ConfigureOnRejected(options);
+        };
+    }
+
+    private static void ConfigureOnRejected(RateLimiterOptions options)
+    {
+        options.OnRejected = async (context, cancellationToken) =>
+        {
+            context.HttpContext.Response.StatusCode = (int)HttpStatusCode.TooManyRequests;
+
+            if (context.Lease.TryGetMetadata(MetadataName.RetryAfter, out var retryAfter))
+            {
+                await context.HttpContext.Response.WriteAsync($"Too many requests. Please try again after {retryAfter.TotalMinutes} minute(s)...", cancellationToken);
+            }
+            else
+            {
+                await context.HttpContext.Response.WriteAsync("Too many requests. Please try again later...", cancellationToken);
+            }
+        };
+    }
+}