simple recipe for using minimal api projects with oakton

build/build.cs

@@ -40,6 +40,10 @@ private static void Main(string[] args)
                 Directory.SetCurrentDirectory(Path.Combine(original, "src", "EnvironmentCheckDemonstrator"));
                 RunCurrentProject("help");
                 RunCurrentProject("describe");
+                
+                Directory.SetCurrentDirectory(Path.Combine(original, "src", "MinimalApi"));
+                RunCurrentProject("help");
+                RunCurrentProject("describe");
             });
 
 
@@ -105,7 +109,7 @@ private static void Main(string[] args)
 
         private static void RunCurrentProject(string args)
         {
-            Run("dotnet", $"run  --framework net5.0 --no-build --no-restore -- {args}");
+            Run("dotnet", $"run --no-build --no-restore -- {args}");
         }
 
 

src/MinimalApi/MinimalApi.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+    <PropertyGroup>
+        <TargetFramework>net6.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\Oakton\Oakton.csproj" />
+    </ItemGroup>
+
+</Project>

src/MinimalApi/Program.cs

@@ -0,0 +1,7 @@
+using Microsoft.AspNetCore.Builder;
+using Oakton;
+
+var builder = WebApplication.CreateBuilder(args);
+var app = builder.Build();
+app.MapGet("/", () => "Hello World!");
+return app.RunOaktonCommandsSynchronously(args);

src/MinimalApi/Properties/launchSettings.json

@@ -0,0 +1,28 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:43449",
+      "sslPort": 44365
+    }
+  },
+  "profiles": {
+    "MinimalApi": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:7197;http://localhost:5197",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

src/MinimalApi/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

src/MinimalApi/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}

src/MvcApp/Startup.cs

@@ -74,12 +74,6 @@ public void Configure(IApplicationBuilder app, IHostEnvironment env)
             app.UseStaticFiles();
             app.UseCookiePolicy();
 
-            app.UseMvc(routes =>
-            {
-                routes.MapRoute(
-                    name: "default",
-                    template: "{controller=Home}/{action=Index}/{id?}");
-            });
         }
     }
 }

src/Oakton.sln

@@ -27,6 +27,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkerService", "WorkerServ
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Net5WebApi", "Net5WebApi\Net5WebApi.csproj", "{59731519-F9A1-4FE2-9525-DDF4214D2E77}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MinimalApi", "MinimalApi\MinimalApi.csproj", "{307092A0-7161-4FD0-9B4B-19A34F323C3A}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -81,6 +83,10 @@ Global
 		{59731519-F9A1-4FE2-9525-DDF4214D2E77}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{59731519-F9A1-4FE2-9525-DDF4214D2E77}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{59731519-F9A1-4FE2-9525-DDF4214D2E77}.Release|Any CPU.Build.0 = Release|Any CPU
+		{307092A0-7161-4FD0-9B4B-19A34F323C3A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{307092A0-7161-4FD0-9B4B-19A34F323C3A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{307092A0-7161-4FD0-9B4B-19A34F323C3A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{307092A0-7161-4FD0-9B4B-19A34F323C3A}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/Oakton/CommandLineHostingExtensions.cs

@@ -12,7 +12,6 @@ namespace Oakton
 
     public static class CommandLineHostingExtensions
     {
-
         /// <summary>
         /// Execute the extended Oakton command line support for your configured WebHostBuilder.
         /// This method would be called within the Task&lt;int&gt; Program.Main(string[] args) method
@@ -25,6 +24,32 @@ public static Task<int> RunOaktonCommands(this IHostBuilder builder, string[] ar
         {
             return Execute(builder, Assembly.GetEntryAssembly(), args);
         }  
+
+        /// <summary>
+        /// Execute the extended Oakton command line support for your configured IHost.
+        /// This method would be called within the Task&lt;int&gt; Program.Main(string[] args) method
+        /// of your AspNetCore application. This usage is appropriate for WebApplication bootstrapping
+        /// </summary>
+        /// <param name="host">An already built IHost</param>
+        /// <param name="args"></param>
+        /// <returns></returns>
+        public static Task<int> RunOaktonCommands(this IHost host, string[] args)
+        {
+            return Execute(new PreBuiltHostBuilder(host), Assembly.GetEntryAssembly(), args);
+        }  
+
+        /// <summary>
+        /// Execute the extended Oakton command line support for your configured IHost.
+        /// This method would be called within the Task&lt;int&gt; Program.Main(string[] args) method
+        /// of your AspNetCore application. This usage is appropriate for WebApplication bootstrapping
+        /// </summary>
+        /// <param name="host">An already built IHost</param>
+        /// <param name="args"></param>
+        /// <returns></returns>
+        public static int RunOaktonCommandsSynchronously(this IHost host, string[] args)
+        {
+            return Execute(new PreBuiltHostBuilder(host), Assembly.GetEntryAssembly(), args).GetAwaiter().GetResult();
+        }  
 
 
         internal static Task<int> Execute(IHostBuilder runtimeSource, Assembly applicationAssembly, string[] args)

src/Oakton/Commands/RunCommand.cs

@@ -22,10 +22,14 @@ public override async Task<bool> Execute(RunInput input)
         {
             using var host = input.BuildHost();
             if (input.CheckFlag)
-                (await EnvironmentChecker.ExecuteAllEnvironmentChecks(host.Services)).Assert();
+            {
+                var checks = await EnvironmentChecker.ExecuteAllEnvironmentChecks(host.Services);
+                checks.Assert();
+            }
 
             var reset = new ManualResetEventSlim();
-            AssemblyLoadContext.GetLoadContext(typeof (RunCommand).GetTypeInfo().Assembly).Unloading += (Action<AssemblyLoadContext>) (context => reset.Set());
+            // ReSharper disable once PossibleNullReferenceException
+            AssemblyLoadContext.GetLoadContext(typeof (RunCommand).Assembly).Unloading += (Action<AssemblyLoadContext>) (context => reset.Set());
             Console.CancelKeyPress += (ConsoleCancelEventHandler) ((sender, eventArgs) =>
             {
                 reset.Set();

src/Oakton/Descriptions/DescribeCommand.cs

@@ -16,71 +16,74 @@ public class DescribeCommand : OaktonAsyncCommand<DescribeInput>
     {
         public override async Task<bool> Execute(DescribeInput input)
         {
-            input.HostBuilder.ConfigureServices(x => x.AddTransient<IDescribedSystemPart, ConfigurationPreview>());
+            using var host = input.BuildHost();
+
+            var config = host.Services.GetRequiredService<IConfiguration>();
+            var configurationPreview = new ConfigurationPreview(config);
 
-            using (var host = input.BuildHost())
-            {
-                var config = host.Services.GetRequiredService<IConfiguration>();
-                var hosting = host.Services.GetService<IHostEnvironment>();
-                var about = new AboutThisAppPart(hosting, config);
+            var hosting = host.Services.GetService<IHostEnvironment>();
+            var about = new AboutThisAppPart(hosting, config);
+            var builtInDescribers = new IDescribedSystemPart[]{about, configurationPreview, new ReferencedAssemblies()};
 
-                var factories = host.Services.GetServices<IDescribedSystemPartFactory>();
-                var parts = host.Services.GetServices<IDescribedSystemPart>()
-                    .Concat(factories.SelectMany(x => x.Parts()))
-                    .Concat(new IDescribedSystemPart[]{about, new ReferencedAssemblies()}).ToArray();
+            var factories = host.Services.GetServices<IDescribedSystemPartFactory>();
+
+            var parts = host.Services.GetServices<IDescribedSystemPart>()
+                .Concat(factories.SelectMany(x => x.Parts()))
+                .Concat(builtInDescribers).ToArray();
+
+            foreach (var partWithServices in parts.OfType<IRequiresServices>())
+            {
+                partWithServices.Resolve(host.Services);
+            }
 
-                foreach (var partWithServices in parts.OfType<IRequiresServices>())
+            if (input.ListFlag)
+            {
+                Console.WriteLine("The registered system parts are");
+                foreach (var part in parts)
                 {
-                    partWithServices.Resolve(host.Services);
+                    Console.WriteLine("* " + part.Title);
                 }
 
-                if (input.ListFlag)
-                {
-                    Console.WriteLine("The registered system parts are");
-                    foreach (var part in parts)
-                    {
-                        Console.WriteLine("* " + part.Title);
-                    }
+                return true;
+            }
 
-                    return true;
-                }
+            if (input.TitleFlag.IsNotEmpty())
+            {
+                parts = parts.Where(x => x.Title == input.TitleFlag).ToArray();
+            }
+            else if (input.InteractiveFlag)
+            {
+                var prompt = new MultiSelectionPrompt<string>()
+                    .Title("What part(s) of your application do you wish to view?")
+                    .PageSize(10)
+                    .AddChoices(parts.Select(x => x.Title));
 
-                if (input.TitleFlag.IsNotEmpty())
-                {
-                    parts = parts.Where(x => x.Title == input.TitleFlag).ToArray();
-                }
-                else if (input.InteractiveFlag)
-                {
-                    var prompt = new MultiSelectionPrompt<string>()
-                        .Title("What part(s) of your application do you wish to view?")
-                        .PageSize(10)
-                        .AddChoices(parts.Select(x => x.Title));
+                var titles = AnsiConsole.Prompt(prompt);
 
-                    var titles = AnsiConsole.Prompt(prompt);
+                parts = parts.Where(x => titles.Contains(x.Title)).ToArray();
+            }
 
-                    parts = parts.Where(x => titles.Contains(x.Title)).ToArray();
-                }
+            if (!input.SilentFlag)
+            {
+                await WriteToConsole(parts);
+            }
 
-                if (!input.SilentFlag)
-                {
-                    await WriteToConsole(parts);
-                }
+            if (!input.FileFlag.IsNotEmpty())
+            {
+                return true;
+            }
 
-                if (input.FileFlag.IsNotEmpty())
-                {
-                    using (var stream = new FileStream(input.FileFlag, FileMode.CreateNew, FileAccess.Write))
-                    {
-                        var writer = new StreamWriter(stream);
+            await using (var stream = new FileStream(input.FileFlag, FileMode.CreateNew, FileAccess.Write))
+            {
+                var writer = new StreamWriter(stream);
 
-                        await WriteText(parts, writer);
-                        await writer.FlushAsync();
-                    }
+                await WriteText(parts, writer);
+                await writer.FlushAsync();
+            }
 
-                    Console.WriteLine("Wrote system description to file " + input.FileFlag);
-                }
+            Console.WriteLine("Wrote system description to file " + input.FileFlag);
 
-                return true;
-            }
+            return true;
         }
 
 

src/Oakton/PreBuiltHostBuilder.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace Oakton
+{
+    internal class PreBuiltHostBuilder : IHostBuilder
+    {
+        private readonly IHost _host;
+        private readonly string _notSupportedMessage;
+
+        public PreBuiltHostBuilder(IHost host)
+        {
+            _host = host;
+            _notSupportedMessage = $"The IHost ({_host}) is already constructed. See https://jasperfx.github.io/oakton for alternative bootstrapping to enable this feature.";
+        }
+
+        public IHostBuilder ConfigureHostConfiguration(Action<IConfigurationBuilder> configureDelegate)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHostBuilder ConfigureAppConfiguration(Action<HostBuilderContext, IConfigurationBuilder> configureDelegate)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHostBuilder ConfigureServices(Action<HostBuilderContext, IServiceCollection> configureDelegate)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHostBuilder UseServiceProviderFactory<TContainerBuilder>(IServiceProviderFactory<TContainerBuilder> factory)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHostBuilder UseServiceProviderFactory<TContainerBuilder>(Func<HostBuilderContext, IServiceProviderFactory<TContainerBuilder>> factory)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHostBuilder ConfigureContainer<TContainerBuilder>(Action<HostBuilderContext, TContainerBuilder> configureDelegate)
+        {
+            throw new NotSupportedException(_notSupportedMessage);
+        }
+
+        public IHost Build()
+        {
+            return _host;
+        }
+
+        public IDictionary<object, object> Properties { get; } = new Dictionary<object, object>();
+    }
+}