How to start creating a Giraffe web project and how to serve it?

Question

Having some trouble with giraffe-template on Mac M1, so decided to set up a Giraffe project manually. Started following the Doing it manually section of the Giraffe README, but got stuck right away, and I also couldn't see mentioned anywhere how the project could be served.

For the record, the Giraffe docs are great. I'm new to .NET, so the parts I'm struggling with are the basics of .NET project management, F#, and ASP.NET Core - it would be unreasonable to expect these topics covered in there.

Answer 1

I have to keep reminding myself that

a Giraffe project plugs into the ASP.NET Core pipeline or is itself an ASP.NET Core application

, so if I can't find answers to my questions in the Giraffe docs, then it is probably because it is an ASP.NET Core topic (or an F# / .NET / etc. one).

How to create and serve a Giraffe project

Steps 0. to 5. follow the Get started with F# with command-line tools (.NET | Microsoft Learn) article.

0. (OPTIONAL) Create a new solution.

   dotnet new sln -o SampleSolution
   

1. Enter the solution's directory.

   cd SampleSolution
   

2. Create an empty ASP.NET Core project.

   dotnet new web -lang "F#" -o src/GiraffeWebExample
   

   INFO The available dotnet new templates are available on the links below. (Both seem to list them all, but not sure which one is more up-to-date.)

   • [Microsoft Learn][.NET CLI] .NET default templates for dotnet new
   • [Microsoft Learn][.NET CLI] dotnet new <TEMPLATE>

3. (OPTIONAL) Add new project to solution.

   dotnet sln add src/GiraffeWebExample/GiraffeWebExample.fsproj
   

4. Enter the project's directory.

   cd src/GiraffeWebExample/
   

5. Install dependencies.

   dotnet add package Microsoft.AspNetCore.App
   dotnet add package Giraffe
   

   NOTE I got a warning below when adding Giraffe, so just pasting it here for completeness' sake:

   /usr/local/share/dotnet/sdk/8.0.202/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.Sdk.DefaultItems.Shared.targets(111,5):
   warning NETSDK1080: A PackageReference to Microsoft.AspNetCore.App is not
   necessary when targeting .NET Core 3.0 or higher. If Microsoft.NET.Sdk.Web
   is used, the shared framework will be referenced automatically. Otherwise,
   the PackageReference should be replaced with a FrameworkReference. 
   [/Users/toraritte/dev/shed/dotnet/giraffe/ByHand/src/ByHand/ByHand.fsproj]
   

6. Add the "entry point".

   NOTE Still haven't figured out what other ways .NET has to set up a web project, but the EntryPoint attribute is covered in the [Microsoft Learn][F# Guide] Console Applications and Explicit Entry Points article.

   I chose to simply copy one of the sample codes from the Doing it manually section; I prefer the more functional approach, so here it is the second one:

   open System
   open Microsoft.AspNetCore.Builder
   open Microsoft.AspNetCore.Hosting
   open Microsoft.Extensions.Hosting
   open Microsoft.Extensions.DependencyInjection
   open Giraffe
   
   let webApp =
       choose [
           route "/ping"   >=> text "pong"
           route "/"       >=> htmlFile "/pages/index.html" ]
   
   let configureApp (app : IApplicationBuilder) =
       // Add Giraffe to the ASP.NET Core pipeline
       app.UseGiraffe webApp
   
   let configureServices (services : IServiceCollection) =
       // Add Giraffe dependencies
       services.AddGiraffe() |> ignore
   
   [<EntryPoint>]
   let main _ =
       Host.CreateDefaultBuilder()
           .ConfigureWebHostDefaults(
               fun webHostBuilder ->
                   webHostBuilder
                       .Configure(configureApp)
                       .ConfigureServices(configureServices)
                       |> ignore)
           .Build()
           .Run()
       0
   

7. Run / serve project.

   dotnet watch run
   

   INFO Started with the Get started with ASP.NET Core article in the ASP.NET Core docs.