20 | 结构化日志组件Serilog：记录对查询分析友好的日志

结构化日志的好处

• 易于检索
• 易于分析统计

场景举例

• 实现日志告警
• 实现上下文的关联
• 实现追踪系统集成

示例

首先我们新建Web程序👉选择API模板
改造Program类

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Serilog;
using Serilog.Formatting.Compact;
using System;
using System.IO;

namespace LoggingSerilogDemo
{
    public class Program
    {
        public static IConfiguration Configuration { get; } = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", false, true)
            .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Production"}.json")
            .AddEnvironmentVariables()
            .Build();

        public static int Main(string[] args)
        {
            Log.Logger = new LoggerConfiguration()
                // 将配置的值传递给Serilog的提供程序
                .ReadFrom.Configuration(Configuration)
                .MinimumLevel.Debug()
                .Enrich.FromLogContext()
                .WriteTo.Console(new RenderedCompactJsonFormatter())
                .WriteTo.File(formatter: new CompactJsonFormatter(), "Logs\\Myapp.txt", rollingInterval: RollingInterval.Day)
                .CreateLogger();

            try
            {
                Log.Information("Starting wen host");
                CreateHostBuilder(args).Build().Run();
                return 0;
            }
            catch (Exception exception)
            {
                Log.Fatal(exception, "Host terminated unexpectedly");
                return 1;
            }
            finally
            {
                Log.CloseAndFlush();
            }
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                })
                .UseSerilog(dispose: true);
    }
}

修改appsetting.json配置文件

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "Serilog": {
    "MinimumLevel": {
      "Default": "Information",
      "Override": {
        "Microsoft": "Error",
        "System": "Information"
      }
    }
  },
  "AllowedHosts": "*"
}