Serilog In .NET Core

As we know, logging is one of the most important topics for any kind of small or big application in software.

With the help of logging not only can we track what's happing behing the application, but also it helps to track any kind of exception. This exception actually comes iton application when it shows the exact method and line numnber with proper message details. So with the help of logging, developers can easily understand what the actual error is.

So I have decided to write a short summary on Serilog in ASP.NET Core 3.1 and its implementations.

As we know that .NET Core has some basic logging features built-in which we have seen in the ILogger interface throughout the.NET Core Application.

But sometimes that's not enough. So what if we want more control over how and where to log the details?

This is where Logging Frameworks comes into the picture.

So Serilog is one of the most popular Libraries for ASP.NET Core Applications.

Here in this section I will try to cover the following topics:

1. What is Serilog?
2. Setup .NET Core Project
3. Logging with the Default Logger
4. Log Levels
5. Packages Installation
6. Console Logging.
7. File Logging.
8. Database Logging.
9. Summary

From the official site:https://serilog.net/, "Serilog provides diagnostic logging to files, the console, and elsewhere. It is easy to set up, has a clean API, and is portable between recent .NET platforms. Unlike other logging libraries, Serilog is built with powerful structured event data in mind."

For the step by step implementations we will create a simple .NET Core Web Application. I am using Visual Studio 2019. I will create a new project and then select ASP.NET Core Web Application project with an empty project template.

Here few default files would be as follows,

• appsettings.json,
• appsettings.Development.json,
• Startup.cs
• Program.cs.

The default Program.cs file would look like this,

As we can see the default logging configuration can be found in app setting.json.

Here I have just used test action to show the default log,

Please see the image below.

This console log will be visible once you switch to Kestrel Webserver.

Do not forget to add dependency Injection in controller constructor.

There are the following log-levels availabe here,

• Trace – Detailed messages with sensitive app data.
• Debug – Useful for the development environment.
• Information – General messages, like the way we mentioned earlier.
• Warning – For unexpected events.
• Error – For exceptions and errors.
• Critical – For failures that may need immediate attention.

Now we have see how to apply default logging. Let's see how to implement Serilog step by step.

First of all we need to know what library we need to install.

So here are the libraries listed below,

Now here we have installed all the required Serilog packages, so let’s go ahead and configure Serilog.

For console logging we don't need to do much extra setup. Here you can see the log in the console window.

For this, we will be required to do the basic setup to configure Serilog at the entry point in .NET Core Application. Here in the Program.cs file.do the following changes.