Add Swagger

src/FrameProcessor/FrameProcessor.csproj

@@ -7,11 +7,13 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="10.0.0" />
     <PackageReference Include="MQTTnet" Version="4.3.7.1207" />
     <PackageReference Include="Serilog.AspNetCore" Version="10.0.0" />
     <PackageReference Include="Serilog.Sinks.Console" Version="6.1.1" />
     <PackageReference Include="Serilog.Sinks.File" Version="7.0.0" />
     <PackageReference Include="SixLabors.ImageSharp" Version="3.1.11" />
+    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="7.2.0" />
   </ItemGroup>
 
 </Project>

src/FrameProcessor/Program.cs

@@ -6,6 +6,7 @@ using FrameProcessor.Mqtt;
 using FrameProcessor.Storage;
 using FrameProcessor.UrlFetch;
 using Microsoft.Extensions.Options;
+using Microsoft.OpenApi;
 using Serilog;
 
 var builder = WebApplication.CreateBuilder(args);
@@ -23,6 +24,34 @@ builder.Host.UseSerilog((context, services, configuration) => configuration
 
 builder.Services.AddControllers();
 
+builder.Services.AddOpenApi(options =>
+{
+    options.AddDocumentTransformer((document, context, _) =>
+    {
+        document.Info.Title = "Frame Processor";
+        document.Info.Version = "v1";
+
+        document.Components ??= new OpenApiComponents();
+        document.Components.SecuritySchemes ??= new Dictionary<string, IOpenApiSecurityScheme>();
+        document.Components.SecuritySchemes["ApiKey"] = new OpenApiSecurityScheme
+        {
+            Type = SecuritySchemeType.ApiKey,
+            In = ParameterLocation.Header,
+            Name = "X-Api-Key",
+            Description = "Shared API key required for /api/* endpoints.",
+        };
+
+        document.Security =
+        [
+            new OpenApiSecurityRequirement
+            {
+                [new OpenApiSecuritySchemeReference("ApiKey", document)] = new List<string>(),
+            },
+        ];
+        return Task.CompletedTask;
+    });
+});
+
 builder.Services.AddOptions<MqttOptions>()
     .Bind(builder.Configuration.GetSection(MqttOptions.SectionName))
     .ValidateDataAnnotations()
@@ -77,6 +106,13 @@ var app = builder.Build();
 // Eagerly resolve FramesRegistry so an invalid frames.json fails startup fast.
 _ = app.Services.GetRequiredService<FramesRegistry>();
 
+app.MapOpenApi();
+app.UseSwaggerUI(options =>
+{
+    options.SwaggerEndpoint("/openapi/v1.json", "Frame Processor v1");
+    options.RoutePrefix = "swagger";
+});
+
 app.UseMiddleware<ApiKeyMiddleware>();
 
 app.MapControllers();