ASP.NET Core 3中的自定義日志記錄

根據我的經驗，通常在API中記錄請求和響應。這樣做可以幫助開發人員調試問題並提供有價值的性能指標。在本教程中，我將介紹如何為ASP.NET Core 3 Web API創建基本的日志記錄解決方案。在這篇文章的結尾，我們將有一個有效的日志記錄解決方案，它將記錄每個請求以及對控制台和文件系統的響應，並且日志將包括API處理每個請求所花費的時間。以下是概述：

1. 先決條件
2. 創建RequestLog和ResponseLog模型
3. 創建ILogForWebAPI
4. 創建WebAPIConsoleLogger
5. 創建WebAPIFileLogger
6. 創建CustomLoggingMiddleware
7. 在啟動中添加自定義日志記錄，然后進行測試

先決條件

您應該熟悉 ASP.NET Core Web API請求管道。

首先，創建一個ASP.NET Core 3 Web API項目。

創建RequestLog和ResponseLog模型

這些類將攜帶我們要記錄的請求和響應數據。

 public class RequestLog
    {
        public Guid Id { get; set; }
        public string Action { get; set; }
        public string URL { get; set; }
        public string IPAddress { get; set; }
        public DateTime TimeStampUtc { get; set; }
    }

 

 public class ResponseLog
{
        public Guid Id { get; set; }
        public string Action { get; set; }
        public string URL { get; set; }
        public int StatusCode { get; set; }
        public long ResponseTimeInMilliseconds { get; set; }
        public DateTime TimeStampUtc { get; set; }
}

 

創建ILogForWebAPI

在這里，我們創建了可以執行兩個操作的日志記錄抽象—日志記錄請求和日志記錄響應。

 public interface ILogForWebAPIs
    {
        Task LogAsync(RequestLog requestLog);
        Task LogAsync(ResponseLog responseLog);
    }

 

創建WebAPIConsoleLogger

遵循單一職責原則（SRP），我們將創建ILogForWebAPI的兩個實現。WebAPIConsoleLogger將負責登錄到控制台，而WebAPIFileLogger將負責登錄到文件系統。我們可以使用Decorator Pattern在單個ILogForWebAPI實例中提供兩個記錄器的功能。每個ILogForWebAPIs實現都將包含ILogForWebAPIs的嵌套實例，如果該實例不為null，則將其調用。

 public class WebAPIConsoleLogger : ILogForWebAPIs
    {
        private readonly ILogForWebAPIs _nextLogger;
        private readonly string _dateTimeFormat = "hh:mm:ss tt";

        public WebAPIConsoleLogger(ILogForWebAPIs nextLogger = null)
        {
            _nextLogger = nextLogger;
        }

        public async Task LogAsync(RequestLog requestLog)
        {
            Console.WriteLine($"Request received from {requestLog.IPAddress} @ {requestLog.TimeStampUtc.ToString(_dateTimeFormat)} (Utc)");
            Console.WriteLine($"{requestLog.Action} {requestLog.URL}");
            Console.WriteLine();

            if (_nextLogger != null)
            {
                await _nextLogger.LogAsync(requestLog);
            }
        }

        public async Task LogAsync(ResponseLog responseLog)
        {
            Console.WriteLine($"Response sent @ {responseLog.TimeStampUtc.ToString(_dateTimeFormat)} (Utc)");
            Console.WriteLine($"{responseLog.StatusCode}: {responseLog.Action} {responseLog.URL}");
            Console.WriteLine($"Response time: {responseLog.ResponseTimeInMilliseconds} ms");
            Console.WriteLine();

            if (_nextLogger != null)
            {
                await _nextLogger.LogAsync(responseLog);
            }
        }
    }

 

創建WebAPIFileLogger

WebAPIFileLogger將序列化模型並將其ID用作文件名，從而為每個請求和響應創建一個json文件。

 public class WebAPIFileLogger : ILogForWebAPIs
    {
        private readonly string _requestDirectory;
        private readonly string _responseDirectory;
        private readonly ILogForWebAPIs _nextLogger;

        public WebAPIFileLogger(string path, ILogForWebAPIs nextLogger = null)
        {
            if (string.IsNullOrWhiteSpace(path))
            {
                throw new ArgumentNullException(nameof(path));
            }

            _requestDirectory = Path.Combine(path, "requests");
            _responseDirectory = Path.Combine(path, "responses");

            if (!Directory.Exists(_requestDirectory))
            {
                Directory.CreateDirectory(_requestDirectory);
            }

            if (!Directory.Exists(_responseDirectory))
            {
                Directory.CreateDirectory(_responseDirectory);
            }

            _nextLogger = nextLogger;
        }

        public async Task LogAsync(RequestLog requestLog)
        {
            var serializedLog = JsonConvert.SerializeObject(requestLog, Formatting.Indented);
            var filePath = Path.Combine(_requestDirectory, $"{requestLog.Id}.json");
            await File.WriteAllTextAsync(filePath, serializedLog);

            if (_nextLogger != null)
            {
                await _nextLogger.LogAsync(requestLog);
            }
        }

        public async Task LogAsync(ResponseLog responseLog)
        {
            var serializedLog = JsonConvert.SerializeObject(responseLog, Formatting.Indented);
            var filePath = Path.Combine(_responseDirectory, $"{responseLog.Id}.json");
            await File.WriteAllTextAsync(filePath, serializedLog);

            if (_nextLogger != null)
            {
                await _nextLogger.LogAsync(responseLog);
            }
        }
    }

 

創建CustomLoggingMiddleware

CustomLoggingMiddleware需要將自身附加到請求管道，然后使用ApplicationServices提供的記錄器記錄請求，最后執行請求管道並記錄響應。

 public static class CustomLoggingMiddleware
    {
        public static void UseCustomLogging(this IApplicationBuilder app)
        {
            app.Use(async (context, next) =>
            {
                var logger = app.ApplicationServices.GetService<ILogForWebAPIs>();

                if (logger is null)
                {
                    throw new Exception($"Add ILogForWebAPIs to your service provider in {nameof(Startup)}.{nameof(Startup.ConfigureServices)}");
                }

                await LogRequestAsync(context, logger);
                var stopWatch = new Stopwatch();
                stopWatch.Start();

                // execute request pipeline
                await next?.Invoke();

                stopWatch.Stop();

                await LogResponseAsync(context, stopWatch.ElapsedMilliseconds, logger);
            });
        }

        private static async Task LogRequestAsync(HttpContext context, ILogForWebAPIs logger)
        {
            var requestLog = new RequestLog
            {
                Id = Guid.NewGuid(),
                Action = context.Request.Method,
                URL = context.Request.Path,
                IPAddress = context.Request.HttpContext.Connection.RemoteIpAddress.ToString(),
                TimeStampUtc = DateTime.UtcNow
            };

            await logger.LogAsync(requestLog);
        }

        private static async Task LogResponseAsync(HttpContext context, long responseTimeInMilliseconds, ILogForWebAPIs logger)
        {
            var responseLog = new ResponseLog
            {
                Id = Guid.NewGuid(),
                Action = context.Request.Method,
                URL = context.Request.Path,
                StatusCode = context.Response.StatusCode,
                ResponseTimeInMilliseconds = responseTimeInMilliseconds,
                TimeStampUtc = DateTime.UtcNow
            };

            await logger.LogAsync(responseLog);
        }
    }

 

在啟動中添加自定義日志記錄，然后進行測試

要獲取我們的API日志記錄，我們只需要做兩件事：

1. 將記錄器添加到Startup.ConfigureServices中的IServiceCollection中
2. 在Startup.Configure中調用UseCustomLogging

注意：如果像下面的示例那樣使用https重定向，建議將自定義日志記錄添加到請求管道中。這樣，您可以確保不記錄重定向。

 

 public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            services.AddTransient<ILogForWebAPIs>((serviceProvider) => new WebAPIConsoleLogger(new WebAPIFileLogger("APILogs")));
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            app.UseCustomLogging();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }

 

要在Visual Studio中查看控制台輸出，請使用項目配置文件運行應用程序並進行測試。

導航到日志目錄以檢查日志文件

{
“ Id”：“ 0c7ffe14-66c3-428c-bffe-0da1dccd9546”，
“ Action”：“ GET”，
“ URL”：“ / weatherforecast”，
“ IPAddress”：“ :: 1”，
“ TimeStampUtc”：“ 2020 -02-13T15：05：27.3373827Z”
}