Advanced Serilog Logging System in ASP.NET Core

Controller-Wise | Day-Wise | Pretty JSON Logs | Production-Ready Architecture

Overview

This repository showcases a highly advanced, production-level logging architecture built with ASP.NET Core + Serilog, featuring:

✔ Automatic log separation per Controller

✔ Daily time-based folders (YYYY-MM-DD)

✔ Pretty JSON Log formatting (human readable)

✔ Dynamic Serilog Map Sink routing

✔ External Log Directory support

✔ Custom Exception Middleware

✔ Enterprise-level observability & debugging

Architecture Diagram

File Structure Overview

Technologies Used

Logging Flow

🔹 1. API Endpoint Throws Exception

Whenever an exception occurs in Controller, Service, or Repository layer → it is intercepted by ExceptionMiddleware.

🔹 2. ExceptionMiddleware Extracts Metadata

It automatically reads: Controller Name (e.g., Employee) , Action Name , Path , Exception Message , Source (class where error occurred)

And constructs a structured log object:

🔹 3. Serilog Map Sink Routes the Log

LogFolder = "Employee" → Serilog routes log to:

E:\AppLogs\CRUD_Operations
└── EmployeeRepository(dynamic handling the folder based on exception)
└── 2025-12-04
└── log.json

🔹 4. PrettyJsonFormatter Writes Log Entries

Every exception is appended to the same log.json file for the day.

Key Endpoints (For Testing)

Employee Controller

GET /Employee/EmployeeDetails

POST /Employee/InsertDetails

Any error here will be stored in:

EmployeeRepository(dynamic handling the folder based on exception)/YYYY-MM-DD/log.json

Why This Logging Architecture is Powerful

✔ Controller-wise separation

Keeps logs organized based on feature/domain.

✔ Day-wise folder structure

Easy to track historical logs per day.

✔ Pretty JSON formatting

Readable, structured, and ready for log ingestion tools.

✔ Middleware-driven logging

Centralized — you never write try/catch manually.

✔ Production-ready

Recommended for enterprise applications and microservices.

Production Recommendations

To make your logging more secure & scalable:

🔐 Security

Never log sensitive data (passwords, tokens, Aadhaar, etc.)

Use environment-based log levels (Error for Prod)

📂 Storage

Store logs on external storage (SSD, Azure Blob, AWS S3)

Rotate logs monthly for performance

🔍 Monitoring

Send logs to ELK, Seq, Splunk, or Azure AppInsights

Add correlation IDs for distributed tracing

How to Run Locally

Step 1: Configure log root

appsettings.json:

"LogSettings": { "ExternalLogRoot": "E:\AppLogs\CRUD_Operations\" }

Step 2: Register Middleware app.UseMiddleware();

Step 3: Run application dotnet run

Logs will be auto-generated as you trigger API errors.

🎯 What You Will Learn From This Project

✔ How to build a real enterprise-level logging system

✔ How to route logs into dynamic folders using Serilog Map

✔ How to write Pretty JSON logs with custom formatters

✔ How to build Exception Handling Middleware

✔ How to maintain logs per controller, per day

✔ How to structure logs for observability tools (ELK, Seq, Kibana)

✔ How to design scalable logging architecture for microservices