📘 Logging in ASP.NET Core with Serilog – A Beginner-Friendly Guide

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Published on: June 3, 2025

Category: Tutorial Tuesday

Tags: ASP.NET Core, Serilog, Logging, .NET Core, Middleware, Application Insights, Dev Tutorial

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🔧 Why Use Serilog?

• Easy syntax and configuration
• Powerful structured logging
• Multiple output sinks (Console, File, Seq, Azure Monitor, etc.)
• Support for filtering, theming, and JSON output

🚀 Step-by-Step Integration in ASP.NET Core

1️⃣ Install Required Packages

Use NuGet Package Manager or .NET CLI:

dotnet add package Serilog.AspNetCore
dotnet add package Serilog.Sinks.Console
dotnet add package Serilog.Sinks.File

2️⃣ Configure Serilog in Program.cs

using Serilog;

Log.Logger = new LoggerConfiguration()
    .MinimumLevel.Debug()
    .WriteTo.Console()
    .WriteTo.File("logs/log.txt", rollingInterval: RollingInterval.Day)
    .CreateLogger();

var builder = WebApplication.CreateBuilder(args);
builder.Host.UseSerilog(); // <-- Register Serilog

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

3️⃣ Verify It Works

Run the app and check the console or logs/log.txt. Example output:

[10:32:45 INF] HTTP GET /api/products responded 200 in 150ms

🔍 Optional: Add Enrichers

Add context like thread ID, process ID, etc.:

using Serilog.Enrichers.Process;
using Serilog.Enrichers.Thread;

Log.Logger = new LoggerConfiguration()
    .Enrich.WithProcessId()
    .Enrich.WithThreadId()
    .WriteTo.Console()
    .CreateLogger();

⚙️ Use Cases in Real-World Apps

• Track API response times
• Log unhandled exceptions
• Send logs to centralized services like Seq or Azure Monitor
• Correlate logs with request IDs in distributed systems

📌 Final Thoughts

Serilog is beginner-friendly but scalable for production. If you're not yet using structured logging in ASP.NET Core—this guide should help you get started today.

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📬 Stay Connected

• 🔗 Blog: www.ajaygangwar.com
• 💼 LinkedIn: Ajay Gangwar
• 📧 Email: seajaygangwar@gmail.com

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