Generate OpenAPI doc on build

Author: DamianEdwards

src/BenchmarksApps/TodosApi/Database.cs

@@ -0,0 +1,64 @@
+using Microsoft.AspNetCore.Hosting.Server;
+using Microsoft.AspNetCore.Hosting.Server.Features;
+using Npgsql;
+
+namespace TodosApi;
+
+internal class DatabaseInitializer : IHostedService
+{
+    private readonly NpgsqlDataSource _db;
+    private readonly ILogger<DatabaseInitializer> _logger;
+    private readonly bool _initDatabase;
+
+    public DatabaseInitializer(NpgsqlDataSource db, IServer server, ILogger<DatabaseInitializer> logger)
+    {
+        _db = db;
+        _logger = logger;
+        _initDatabase = Environment.GetEnvironmentVariable("SUPPRESS_DB_INIT") != "true"
+            // Only run if this is an actual IServer implementation with addresses to listen on.
+            // Will not be the case for TestServer, NoopServer injected by the OpenAPI doc generator tool, etc.
+            && server.Features.Get<IServerAddressesFeature>() is { Addresses.Count: >0 };
+    }
+
+    public Task StartAsync(CancellationToken cancellationToken)
+    {
+        if (_initDatabase)
+        {
+            return Initialize(cancellationToken);
+        }
+
+        _logger.LogInformation("Database initialization disabled for connection string '{connectionString}'", _db.ConnectionString);
+        return Task.CompletedTask;
+    }
+
+    public Task StopAsync(CancellationToken cancellationToken)
+    {
+        return Task.CompletedTask;
+    }
+
+    private async Task Initialize(CancellationToken cancellationToken = default)
+    {
+        // NOTE: Npgsql removes the password from the connection string
+        _logger.LogInformation("Ensuring database exists and is up to date at connection string '{connectionString}'", _db.ConnectionString);
+
+        var sql = $"""
+                CREATE TABLE IF NOT EXISTS public.todos
+                (
+                    {nameof(Todo.Id)} SERIAL PRIMARY KEY,
+                    {nameof(Todo.Title)} text NOT NULL,
+                    {nameof(Todo.DueBy)} date NULL,
+                    {nameof(Todo.IsComplete)} boolean NOT NULL DEFAULT false
+                );
+                DELETE FROM public.todos;
+                INSERT INTO
+                    public.todos ({nameof(Todo.Title)}, {nameof(Todo.DueBy)}, {nameof(Todo.IsComplete)})
+                VALUES
+                    ('Wash the dishes.', CURRENT_DATE, true),
+                    ('Dry the dishes.', CURRENT_DATE, true),
+                    ('Turn the dishes over.', CURRENT_DATE, false),
+                    ('Walk the kangaroo.', CURRENT_DATE + INTERVAL '1 day', false),
+                    ('Call Grandma.', CURRENT_DATE + INTERVAL '1 day', false);
+                """;
+        await _db.ExecuteAsync(sql, cancellationToken);
+    }
+}

src/BenchmarksApps/TodosApi/DatabaseInitializer.cs

@@ -1,3 +1,6 @@
+#if ENABLE_OPENAPI
+using Microsoft.OpenApi.Models;
+#endif
 using Npgsql;
 using TodosApi;
 
@@ -21,6 +24,7 @@
     var appSettings = sp.GetRequiredService<IOptions<AppSettings>>().Value;
     return new NpgsqlSlimDataSourceBuilder(appSettings.ConnectionString).Build();
 });
+builder.Services.AddHostedService<DatabaseInitializer>();
 
 // Configure JSON serialization
 builder.Services.ConfigureHttpJsonOptions(options =>
@@ -36,16 +40,26 @@
 // Problem details
 builder.Services.AddProblemDetails();
 
-var app = builder.Build();
+#if ENABLE_OPENAPI
+// Configure OpenAPI
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen(c =>
+{
+    c.SwaggerDoc("v1", new OpenApiInfo { Title = "Todos API", Version = "v1" });
+});
+#endif
 
-await Database.Initialize(app.Services, app.Logger);
+var app = builder.Build();
 
 if (!app.Environment.IsDevelopment())
 {
     app.UseExceptionHandler();
 }
 
+app.MapShortCircuit(StatusCodes.Status404NotFound, "/favicon.ico");
+
 app.MapHealthChecks("/health");
+
 // Enables testing request exception handling behavior
 app.MapGet("/throw", void () => throw new InvalidOperationException("You hit the throw endpoint"));
 

src/BenchmarksApps/TodosApi/Program.cs

@@ -10,13 +10,26 @@
     <UserSecretsId>b8ffb8d3-b768-460b-ac1f-ef267c954c85</UserSecretsId>
     <PublishAot>true</PublishAot>
     <EnableConfigurationBindingGenerator>false</EnableConfigurationBindingGenerator>
-    <EnableLogging Condition="$(Configuration.StartsWith('Debug'))">true</EnableLogging>
+    <EnableLogging Condition=" '$(EnableLogging)' == '' and $(Configuration.StartsWith('Debug')) ">true</EnableLogging>
+    <EnableOpenApi Condition=" '$(EnableOpenApi)' == '' and $(Configuration.StartsWith('Debug')) ">true</EnableOpenApi>
     <DefineConstants Condition=" '$(EnableLogging)' == 'true' ">$(DefineConstants);ENABLE_LOGGING</DefineConstants>
+    <DefineConstants Condition=" '$(EnableOpenApi)' == 'true' ">$(DefineConstants);ENABLE_OPENAPI</DefineConstants>
   </PropertyGroup>
-
+  
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="8.0.0-preview.*" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0-preview.*" />
     <PackageReference Include="Npgsql" Version="8.0.0-preview.3" />
+    <Content Update="appSettings.Development.json" CopyToPublishDirectory="false" />
+  </ItemGroup>
+
+  <PropertyGroup Condition=" '$(EnableOpenApi)' == 'true' ">
+    <OpenApiGenerateDocuments>true</OpenApiGenerateDocuments>
+    <OpenApiDocumentsDirectory>./</OpenApiDocumentsDirectory>
+  </PropertyGroup>
+
+  <ItemGroup Condition=" '$(EnableOpenApi)' == 'true' ">
+    <PackageReference Include="Microsoft.Extensions.ApiDescription.Server" Version="8.0.0-preview.*" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="6.5.0" />
   </ItemGroup>
 </Project>