feature(#6): this commit introduces correlation support to the project, improving observability and tracing

Author: https-richardy

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Constants/Headers.cs

@@ -3,4 +3,10 @@
 public static class Headers
 {
     public const string Credential = "X-Credential";
+    public const string Location = "Location";
+    public const string Link = "Link";
+    public const string Pagination = "X-Pagination";
+    public const string Authorization = "Authorization";
+    public const string Idempotency = "Idempotency-Key";
+    public const string Correlation = "Correlation";
 }

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Extensions/HttpClientsExtension.cs

@@ -8,6 +8,7 @@ public static void AddHttpClients(this IServiceCollection services, ISettings se
         // register transient lifetime interceptors here
         // https://learn.microsoft.com/en-us/aspnet/web-api/overview/advanced/httpclient-parameters-handlers
         services.AddTransient<CredentialInterceptor>();
+        services.AddTransient<CorrelationInterceptor>();
 
         var paymentClient = services.AddHttpClient<IAbacatePayClient, AbacatePayClient>(client =>
         {
@@ -16,5 +17,6 @@ public static void AddHttpClients(this IServiceCollection services, ISettings se
         });
 
         paymentClient.AddHttpMessageHandler<CredentialInterceptor>();
+        paymentClient.AddHttpMessageHandler<CorrelationInterceptor>();
     }
 }

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Extensions/HttpPipelineExtension.cs

@@ -13,6 +13,7 @@ public static void UseHttpPipeline(this IApplicationBuilder app)
         app.UseAuthentication();
         app.UseAuthorization();
 
+        app.UseCorrelationMiddleware();
         app.UseEndpoints(endpoints =>
         {
             endpoints.MapControllers();

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Interceptors/CorrelationInterceptor.cs

@@ -0,0 +1,17 @@
+namespace Comanda.Payments.WebApi.Interceptors;
+
+public sealed class CorrelationInterceptor(IHttpContextAccessor accessor) : DelegatingHandler
+{
+    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        var correlation = accessor.HttpContext?.Items[Headers.Correlation]?.ToString();
+
+        if (!string.IsNullOrWhiteSpace(correlation))
+        {
+            request.Headers.Remove(Headers.Correlation);
+            request.Headers.Add(Headers.Correlation, correlation);
+        }
+
+        return await base.SendAsync(request, cancellationToken);
+    }
+}

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Middlewares/CorrelationMiddleware.cs

@@ -0,0 +1,29 @@
+namespace Comanda.Payments.WebApi.Middlewares;
+
+public sealed class CorrelationMiddleware(RequestDelegate next)
+{
+    public async Task InvokeAsync(HttpContext context)
+    {
+        var correlationId = context.Request.Headers[Headers.Correlation].FirstOrDefault();
+
+        if (string.IsNullOrWhiteSpace(correlationId))
+            correlationId = context.TraceIdentifier;
+
+        context.Items[Headers.Correlation] = correlationId;
+        context.Response.Headers[Headers.Correlation] = correlationId;
+
+        /* enriches the logging scope with the current correlation identifier, ensuring all logs within this request pipeline share the same identifier */
+        /* more details: https://microsoft.github.io/code-with-engineering-playbook/observability/correlation-id/ */
+
+        using (LogContext.PushProperty(Headers.Correlation, correlationId))
+        using (SentrySdk.PushScope())
+        {
+            SentrySdk.ConfigureScope(scope =>
+            {
+                scope.SetTag("correlation_id", correlationId);
+            });
+
+            await next(context);
+        }
+    }
+}

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Middlewares/CorrelationMiddlewareExtension.cs

@@ -0,0 +1,10 @@
+namespace Comanda.Payments.WebApi.Middlewares;
+
+[ExcludeFromCodeCoverage(Justification = "contains only dependency injection")]
+public static class CorrelationMiddlewareExtension
+{
+    public static IApplicationBuilder UseCorrelationMiddleware(this IApplicationBuilder app)
+    {
+        return app.UseMiddleware<CorrelationMiddleware>();
+    }
+}

Boundaries/Comanda.Payments/Source/Comanda.Payments.WebApi/Usings.cs

@@ -8,6 +8,7 @@
 global using Comanda.Payments.WebApi.Constants;
 global using Comanda.Payments.WebApi.Interceptors;
 global using Comanda.Payments.WebApi.Extensions;
+global using Comanda.Payments.WebApi.Middlewares;
 global using Comanda.Payments.Domain.Errors;
 
 global using Comanda.Payments.Application.Payloads.Traceability;
@@ -25,4 +26,5 @@
 
 global using Scalar.AspNetCore;
 global using Serilog;
+global using Serilog.Context;
 global using FluentValidation.AspNetCore;