ASP.NET Core Web App 將 404 請求記錄為警告

Question

如果我使用dotnet new mvc創建一個新的ASP.NET Core Web App (Model-View-Controller) ，它已經配置了開箱即用的日志記錄。

但是，http 請求錯誤代碼記錄為信息事件。

info: Microsoft.AspNetCore.Hosting.Internal.WebHost[1]
      Request starting HTTP/1.1 GET https://localhost:5001/doesnotexists
info: Microsoft.AspNetCore.Hosting.Internal.WebHost[2]
      Request finished in 4.4052ms 404

是否可以通過調查和重寫日志事件將此行為更改為 (4xx -> warning, 5xx -> error) .ie。

我已經閱讀了https://docs.microsoft.com/en-us/aspnet/core/fundamentals/logging/?view=aspnetcore-2.2

這看起來很有希望，但我沒有找到用於此目的的鈎子

    var webHost = new WebHostBuilder()
        .UseKestrel()
        .UseContentRoot(Directory.GetCurrentDirectory())
        .ConfigureLogging((hostingContext, logging) =>
        {
            // investigate and rewrite log event
        })
        .UseStartup<Startup>()
        .Build()

Answer 1

單線解決方案

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

using Microsoft.Extensions.Logging;

namespace temp
{
    public class Startup
    {    
        public void Configure(IApplicationBuilder app, IHostEnvironment env, ILogger<Startup> logger)
        {

            ...

            app.UseStatusCodePages(async context =>
            {
                var code = context.HttpContext.Response.StatusCode;
                if (code == 404) {
                    logger.Log(LogLevel.Error, null, "log message");
                }
            });

            ...

        }
    }
}

Answer 2

您需要實現自己的ILogger和ILoggerProvider 。

一個簡單的演示，如：

1. CustomLogger

    public class CustomLogger : ILogger { public CustomLogger() { } public IDisposable BeginScope<TState>(TState state)=> NullScope.Instance; public bool IsEnabled(LogLevel logLevel) => true; public void Log<TState>( LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter ) { var msg = formatter(state, exception); if (msg.Contains("404")) { logLevel = LogLevel.Warning; } Console.WriteLine($"{ GetLogLevelString(logLevel) } : { eventId } { msg } { exception }"); } private static string GetLogLevelString(LogLevel logLevel) { switch (logLevel) { case LogLevel.Trace: return "trce"; case LogLevel.Debug: return "dbug"; case LogLevel.Information: return "info"; case LogLevel.Warning: return "warn"; case LogLevel.Error: return "fail"; case LogLevel.Critical: return "crit"; default: throw new ArgumentOutOfRangeException(nameof(logLevel)); } } }

2. CustomLoggerProvider

    public class CustomLoggerProvider : ILoggerProvider { public ILogger CreateLogger(string categoryName) { return new CustomLogger(); } public void Dispose() { } }

3. 注冊上面的代碼

    public static IWebHostBuilder CreateWebHostBuilder(string[] args) => WebHost.CreateDefaultBuilder(args) .UseStartup<Startup>() .ConfigureLogging(config => { config.ClearProviders(); config.AddProvider(new CustomLoggerProvider()); });

   您可以檢查Logging並實現您自己的日志提供程序。