Настройка логирования — C# (.NET, `ILogger` + Serilog)

using Microsoft.Extensions.Logging;
using Serilog;

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

var builder = Host.CreateApplicationBuilder(args);
builder.Services.AddLogging(logging => {
    logging.AddSerilog();
});

var app = builder.Build();
var logger = app.Services.GetRequiredService<ILogger<Program>>();
logger.LogInformation("Приложение запущено. Пользователь: {UserId}", userId);