DotNet By Ajay: How to Implement Serilog in ASP.NET Core (.NET 8/9)

Published on: June 17, 2025
Category: Dev Tutorials / Logging
Tags: .NET Core, ASP.NET Core, Serilog, Structured Logging, Dev Tutorial

🔍 Why Logging Matters

Logging is crucial for debugging, monitoring, and maintaining applications. In modern .NET development, Serilog has emerged as a powerful logging library offering structured log data.

⚙️ What is Serilog?

Serilog is a diagnostic logging library for .NET applications. It supports structured logging and allows you to route logs to multiple outputs (called sinks) such as:

Console
File
Seq
Elasticsearch

🚀 Step-by-Step Setup in ASP.NET Core

1️⃣ Install NuGet Packages


Install-Package Serilog.AspNetCore
Install-Package Serilog.Sinks.File

2️⃣ Program.cs Configuration (.NET 6+)


using Serilog;

Log.Logger = new LoggerConfiguration()
    .WriteTo.Console()
    .WriteTo.File("Logs/app-log.txt", rollingInterval: RollingInterval.Day)
    .CreateLogger();

var builder = WebApplication.CreateBuilder(args);
builder.Host.UseSerilog();

var app = builder.Build();
app.Run();

3️⃣ Logging in Controllers/Services


public class HomeController : Controller
{
    private readonly ILogger<HomeController> _logger;

    public HomeController(ILogger<HomeController> logger)
    {
        _logger = logger;
    }

    public IActionResult Index()
    {
        _logger.LogInformation("Visited Home Page");
        return View();
    }
}

💡 Best Practices

Use rolling logs to prevent large file sizes
Store logs outside of the web root
Use structured logs with properties for easier filtering

🧪 Output Sample


[2025-06-17 10:45:22 INF] Visited Home Page

📌 Summary

Serilog offers a flexible, powerful way to manage logging in .NET applications. It simplifies diagnostics and helps you trace issues efficiently with minimal performance impact.

DotNet By Ajay

June 17, 2025

How to Implement Serilog in ASP.NET Core (.NET 8/9) – Step-by-Step Logging Guide