Serilog - Filter out the ASP.NET Core info

When you are using the built-in logging in ASP.NET Core, you can filter out specific information by changing the log levels in the appsettings.json:

	{
	"Logging": {
	"LogLevel": {
	"Default": "Information",
	"Microsoft.AspNetCore": "Warning"
	}
	}
	}

view raw appsettings.json hosted with ❤ by GitHub

But when you switch to Serilog, this no longer works and the configuration values are ignored.

Our original configuration looked like this:

	using Serilog;
	using Serilog.Events;
	public class Program
	{
	public static int Main(string[] args)
	{
	// Create the Serilog logger, and configure the sinks
	Log.Logger = new LoggerConfiguration()
	.Enrich.FromLogContext()
	.WriteTo.File("logs.txt")
	.CreateLogger();
	// Wrap creating and running the host in a try-catch block
	try
	{
	Log.Information("Starting host");
	CreateHostBuilder(args).Build().Run();
	return 0;
	}
	catch (Exception ex)
	{
	Log.Fatal(ex, "Host terminated unexpectedly");
	return 1;
	}
	finally
	{
	Log.CloseAndFlush();
	}
	}
	public static IHostBuilder CreateHostBuilder(string[] args) =>
	Host.CreateDefaultBuilder(args)
	.UseSerilog() // <- Add this line
	.ConfigureWebHostDefaults(webBuilder =>
	{
	webBuilder.UseStartup<Startup>();
	});
	}

view raw Program.cs hosted with ❤ by GitHub

Here is what was logged by default after switching to Serilog:

2022-02-03 12:17:07.861 +01:00 [WRN] Failed to determine the https port for redirect.

2022-02-03 12:17:58.429 +01:00 [WRN] Failed to determine the https port for redirect.

2022-02-03 12:19:19.555 +01:00 [WRN] Failed to determine the https port for redirect.

2022-02-03 12:20:21.553 +01:00 [INF] OnStarted has been called.

2022-02-03 12:20:21.631 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.631 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.631 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.636 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.639 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.639 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.640 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.640 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.640 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.640 +01:00 [INF] Request starting HTTP/1.1 POST http://localhost/mail/ application/json;+charset=utf-8 318

2022-02-03 12:20:21.671 +01:00 [WRN] Failed to determine the https port for redirect.

2022-02-03 12:20:21.677 +01:00 [INF] Executing endpoint 'Mailing.API.Controllers.MailController.Send (Mailing.API)'

2022-02-03 12:20:21.677 +01:00 [INF] Executing endpoint 'Mailing.API.Controllers.MailController.Send (Mailing.API)'

2022-02-03 12:20:21.677 +01:00 [INF] Executing endpoint 'Mailing.API.Controllers.MailController.Send (Mailing.API)'

2022-02-03 12:20:21.706 +01:00 [INF] Route matched with {action = "Send", controller = "Mail"}. Executing controller action with signature System.Threading.Tasks.Task`1[Microsoft.AspNetCore.Mvc.IActionResult] Send(Mailing.DTO.SendMailMessage, System.Threading.CancellationToken) on controller Mailing.API.Controllers.MailController (Mailing.API).

2022-02-03 12:20:21.717 +01:00 [INF] Route matched with {action = "Send", controller = "Mail"}. Executing controller action with signature System.Threading.Tasks.Task`1[Microsoft.AspNetCore.Mvc.IActionResult] Send(Mailing.DTO.SendMailMessage, System.Threading.CancellationToken) on controller Mailing.API.Controllers.MailController (Mailing.API).

2022-02-03 12:20:21.729 +01:00 [INF] Route matched with {action = "Send", controller = "Mail"}. Executing controller action with signature System.Threading.Tasks.Task`1[Microsoft.AspNetCore.Mvc.IActionResult] Send(Mailing.DTO.SendMailMessage, System.Threading.CancellationToken) on controller Mailing.API.Controllers.MailController (Mailing.API).

2022-02-03 12:20:21.794 +01:00 [INF] Configured endpoint mediator, Consumer: Mailing.API.Domain.MailConsumer

2022-02-03 12:20:21.900 +01:00 [INF] Executing action method Mailing.API.Controllers.MailController.Send (Mailing.API) - Validation state: "Valid"

2022-02-03 12:20:21.900 +01:00 [INF] Executing action method Mailing.API.Controllers.MailController.Send (Mailing.API) - Validation state: "Valid"

2022-02-03 12:20:21.900 +01:00 [INF] Executing action method Mailing.API.Controllers.MailController.Send (Mailing.API) - Validation state: "Valid"

Whoops! That’s way too much information.

To fix it, you can override the minimal loglevel in Serilog for specific targets:

	Log.Logger = new LoggerConfiguration()
	.MinimumLevel.Debug()
	.MinimumLevel.Override("Microsoft", LogEventLevel.Information)
	// Filter out ASP.NET Core infrastructre logs that are Information and below
	.MinimumLevel.Override("Microsoft.AspNetCore", LogEventLevel.Warning)
	.Enrich.FromLogContext()

view raw Program.cs hosted with ❤ by GitHub

This will help you to keep the amount of log data under control.