Logging

// Middleware to set correlation IDpublic class CorrelationIdMiddleware(RequestDelegate next){    private const string CorrelationIdHeader = "X-Correlation-Id";
    public async Task InvokeAsync(HttpContext context)    {        var correlationId = context.Request.Headers[CorrelationIdHeader].FirstOrDefault()            ?? Guid.NewGuid().ToString();
        context.Items["CorrelationId"] = correlationId;        context.Response.Headers[CorrelationIdHeader] = correlationId;
        using (LogContext.PushProperty("CorrelationId", correlationId))        {            await next(context);        }    }}
// Program.cs — register early so every downstream log carries the IDapp.UseMiddleware<CorrelationIdMiddleware>();

// Program.csbuilder.Services.AddHealthChecks()    .AddNpgSql(builder.Configuration.GetConnectionString("Default")!,        name: "database", tags: ["ready"])    .AddRedis(builder.Configuration.GetConnectionString("Redis")!,        name: "redis", tags: ["ready"])    .AddRabbitMQ(builder.Configuration.GetConnectionString("RabbitMq")!,        name: "rabbitmq", tags: ["ready"]);
// Map endpointsapp.MapHealthChecks("/health/live", new HealthCheckOptions{    Predicate = _ => false // No dependency checks — just "am I running?"});
app.MapHealthChecks("/health/ready", new HealthCheckOptions{    Predicate = check => check.Tags.Contains("ready")});

// BAD — logging credentialslogger.LogInformation("User logged in: {Email} with password {Password}", email, password);
// GOOD — log identifiers, never secrets or PII at Information levellogger.LogInformation("User {UserId} logged in", userId);

// BAD — all checks run for liveness AND readinessapp.MapHealthChecks("/health");
// GOOD — separate liveness (am I running?) from readiness (can I serve traffic?)app.MapHealthChecks("/health/live", new() { Predicate = _ => false });app.MapHealthChecks("/health/ready", new() { Predicate = c => c.Tags.Contains("ready") });

// BAD — hand-rolling Serilog bootstrap here from memorybuilder.Host.UseSerilog(...);  // legacy API — the serilog skill forbids this
// GOOD — load the serilog skill and use its two-stage AddSerilog() bootstrapbuilder.Services.AddSerilog((services, lc) => lc.ReadFrom.Configuration(builder.Configuration)...);