asp.net core中使用Serilog以及自定義Enricher

時間 2020-11-12

標籤 git github web json api app asp.net async ide 欄目 ASP 简体版

原文原文鏈接

Serilog簡介

與其餘許多.NET庫同樣，Serilog還提供了對文件，控制檯等的基本診斷日誌記錄。它易於設置，具備簡潔的API，而且能夠在最新的.NET平臺之間移植。git

使用和配置、自定義Enricher

因爲 serilog 配置信息比較多，避免硬編碼代碼中，咱們在 appsetting.jgon 同級目錄中新建一個 serilogsetting.json 的日誌配置文件，簡單內容以下:github

{
	"Serilog": {
		"Using": [ "Serilog.Sinks.Console", "Serilog.Sinks.Seq" ],
		"MinimumLevel": {
			"Default": "Information",
			"Override": {
				"System": "Error",
				"Microsoft": "Error"
			}
		},
		"WriteTo": [
			{
				"Name": "Console"
			},
			{
				"Name": "Seq",
				"Args": {
					"serverUrl": "http://localhost:5341/",
					"apiKey": "L2on8gpgjose5uldhdch"
				}
			}
		]
	}
}

更多配置內容請參考：serilog wiki 文檔web

接下來，在 Program.cs 中添加一個方法，初始化這些配置，而後重寫下構建主機的代碼：json

public class Program
{
    public static int Main(string[] args)
    {
        var logConfig = GetLogConfig();
        Log.Logger = new LoggerConfiguration()
                     .ReadFrom.Configuration(logConfig)
                     .Enrich.FormLogContext()
                     .CreateLogger(); 
        try
        {
            // web host 初始化
            var host = BuildWebHost(args);
            host.Run();
            return 0;
        }
        catch(Exception e)
        {
            Log.Fatal(ex, "{ApplicationContext} 出現錯誤:{messsage} !", AppName, ex.Message);
            return 1;
        }
        finally
        {
            Log.CloseAndFlush();
        }
    }
    
    /// <summary>
    /// 讀取日誌配置
    /// </summary>
    /// <returns></returns>
    private static IConfiguration GetLogConfig()
    {
        var builder = new ConfigurationBuilder()
                      .AddJsonFile("serilogsetting.json", optional: false, reloadOnChange: true);
        return builder.Build();
    
    }
}

而後，添加一個自定義Enircher,用來記錄HttpContext，的數據。_enrichAction則能夠自定義，默認記錄ip，請求路徑，請求方法，和返回響應碼：api

public class HttpContextEnricher:ILogEventEnricher
{
    private readonly IServiceProvider _serviceProvider;
    private readonly Action<LogEvent, ILogEventPropertyFactory, HttpContext> _enrichAction;
    
    public HttpContextEnricher(IServiceProvider serviceProvider) : this(serviceProvider, null)
    {}
      
    public HttpContextEnricher(IServiceProvider serviceProvider, Action<LogEvent, ILogEventPropertyFactory, HttpContext> enrichAction)
    {
        _serviceProvider = serviceProvider;
        if (enrichAction == null)
        {
            _enrichAction = (logEvent, propertyFactory, httpContext) =>{
                var x_forwarded_for = new StringValues();
                if (httpContext.Request.Headers.ContainsKey("X-Forwarded-For"))
                {
                   x_forwarded_for = httpContext.Request.Headers["X-Forwarded-For"];
                }
                logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("client_ip", JsonConvert.SerializeObject(x_forwarded_for)));
                logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("request_path", httpContext.Request.Path));
                logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("request_method", httpContext.Request.Method));
                 if (httpContext.Response.HasStarted)
                 {
                     logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("response_status", httpContext.Response.StatusCode));
                 }
            }
        }else{
            _enrichAction = enrichAction;
        }
    }
    
    
    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
    {
        var httpContext = _serviceProvider.GetService<IHttpContextAccessor>()?.HttpContext;
         if (null != httpContext){
             _enrichAction.Invoke(logEvent, propertyFactory, httpContext);
         }
    }
    
}

如今，咱們添加了一個記錄HttpContext的Enricher，可是怎麼用起來呢，怎麼添加到日誌對象中呢。就要靠asp.net core的中間件了。新建一個HttpContextLogMiddleware中間件：app

public class HttpContextLogMiddleware
{
    private readonly RequestDelegate _next;

    public HttpContextLogMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        var serviceProvider = context.RequestServices;
        // 將咱們自定義的Enricher添加到LogContext中。
        // LogContext功能很強大，能夠動態添加屬性，具體使用介紹，參見官方wiki文檔
        using (LogContext.Push(new HttpContextEnricher(serviceProvider)))
        {
            await _next(context);
        }
    }
}

// 使用擴展方法形式注入中間件
public static IApplicationBuilder UseHttpContextLog(
    this IApplicationBuilder builder)
{
    return builder.UseMiddleware<HttpContextLogMiddleware>();
}

這樣，咱們就創建了一箇中間件，接下來在Startup.cs的Configure方法中app.UseHttpContextLog();便可。asp.net