Add global rate limiting sample

Giraffe.sln

@@ -34,6 +34,8 @@ Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "ResponseCachingApp", "sampl
 EndProject
 Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "NewtonsoftJson", "samples\NewtonsoftJson\NewtonsoftJson.fsproj", "{A08230F1-DA24-4059-A7F9-4743B36DD3E9}"
 EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "RateLimiting", "samples\RateLimiting\RateLimiting.fsproj", "{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -104,6 +106,18 @@ Global
 		{A08230F1-DA24-4059-A7F9-4743B36DD3E9}.Release|x64.Build.0 = Release|Any CPU
 		{A08230F1-DA24-4059-A7F9-4743B36DD3E9}.Release|x86.ActiveCfg = Release|Any CPU
 		{A08230F1-DA24-4059-A7F9-4743B36DD3E9}.Release|x86.Build.0 = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|x64.Build.0 = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Debug|x86.Build.0 = Debug|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|x64.ActiveCfg = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|x64.Build.0 = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|x86.ActiveCfg = Release|Any CPU
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -118,5 +132,6 @@ Global
 		{0E15F922-7A44-4116-9DAB-FAEB94392FEC} = {B9B26DDC-608C-42FE-9AB9-6CF0EE4920CD}
 		{FA102AC4-4608-42F9-86C1-1472B416A76E} = {9E6451FB-26E0-4AE4-A469-847F9602E999}
 		{A08230F1-DA24-4059-A7F9-4743B36DD3E9} = {9E6451FB-26E0-4AE4-A469-847F9602E999}
+		{D5916FAA-2EBB-4FDD-B474-9DE37B60D641} = {9E6451FB-26E0-4AE4-A469-847F9602E999}
 	EndGlobalSection
 EndGlobal

samples/RateLimiting/Program.fs

@@ -0,0 +1,56 @@
+open System
+open Microsoft.AspNetCore.Http
+open Microsoft.AspNetCore.Builder
+open Microsoft.Extensions.DependencyInjection
+open Microsoft.Extensions.Hosting
+open Giraffe
+open Giraffe.EndpointRouting
+open Microsoft.AspNetCore.RateLimiting
+open System.Threading.RateLimiting
+
+let endpoints: list<Endpoint> = [ GET [ route "/" (text "Hello World") ] ]
+
+let notFoundHandler = text "Not Found" |> RequestErrors.notFound
+
+let configureApp (appBuilder: IApplicationBuilder) =
+    appBuilder
+        .UseRouting()
+        .UseRateLimiter()
+        .UseGiraffe(endpoints)
+        .UseGiraffe(notFoundHandler)
+
+let configureServices (services: IServiceCollection) =
+    // From https://blog.maartenballiauw.be/post/2022/09/26/aspnet-core-rate-limiting-middleware.html
+    let configureRateLimiter (options: RateLimiterOptions) =
+        options.RejectionStatusCode <- StatusCodes.Status429TooManyRequests
+
+        options.GlobalLimiter <-
+            PartitionedRateLimiter.Create<HttpContext, string>(fun httpContext ->
+                RateLimitPartition.GetFixedWindowLimiter(
+                    partitionKey = httpContext.Request.Headers.Host.ToString(),
+                    factory =
+                        (fun _partition ->
+                            new FixedWindowRateLimiterOptions(
+                                AutoReplenishment = true,
+                                PermitLimit = 10,
+                                QueueLimit = 0,
+                                Window = TimeSpan.FromSeconds(1)
+                            )
+                        )
+                )
+            )
+
+    services.AddRateLimiter(configureRateLimiter).AddRouting().AddGiraffe()
+    |> ignore
+
+[<EntryPoint>]
+let main args =
+    let builder = WebApplication.CreateBuilder(args)
+    configureServices builder.Services
+
+    let app = builder.Build()
+
+    configureApp app
+    app.Run()
+
+    0

samples/RateLimiting/README.md

@@ -0,0 +1,17 @@
+# Rate Limiting Sample
+
+This sample project shows how one can configure ASP.NET's built-in [rate limiting middleware](https://learn.microsoft.com/en-us/aspnet/core/performance/rate-limit?view=aspnetcore-8.0).
+
+Notice that this rate limiting configuration is very simple, and for real life scenarios you'll need to figure out what is the best strategy to use for your server.
+
+To make it easier to test this project locally, and see the rate limiting middleware working, you can use the `rate-limiting-test.fsx` script:
+
+```bash
+# start the server
+dotnet run .
+# if you want to keep using the same terminal, just start this process in the background
+
+# then, you can use this script to test the server, and confirm that the rate-limiting
+# middleware is really working
+dotnet fsi rate-limiting-test.fsx
+```

samples/RateLimiting/RateLimiting.fsproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../../src/Giraffe/Giraffe.fsproj" />
+  </ItemGroup>
+
+</Project>

samples/RateLimiting/rate-limiting-test.fsx

@@ -0,0 +1,20 @@
+open System
+open System.IO
+open System.Net.Http
+
+let request = new HttpClient(BaseAddress = new Uri("http://localhost:5000"))
+
+#time
+
+seq { 1..100 }
+|> Seq.map (fun _ -> request.GetAsync "/" |> Async.AwaitTask)
+|> Async.Parallel
+|> Async.RunSynchronously
+|> Seq.iteri (fun i response ->
+    printfn "\nResponse %i status code: %A" i response.StatusCode
+
+    let responseReader = new StreamReader(response.Content.ReadAsStream())
+    printfn "Response %i content: %A" i (responseReader.ReadToEnd())
+)
+
+#time