C#教程之[开源]基于Log4Net简单实现KafkaAppender

背景#

1. 基于之前基于Log4Net本地日志服务简单实现 实现本地日志服务，但是随着项目开发演进，本地日志服务满足不了需求，譬如在预发布环境或者生产环境，不可能让开发人员登录查看本地日志文件分析。
2. Kafka+ELK日志服务套件，可以在线日志服务可以解决上述问题，并且提供丰富报表分析等等；
3. 具体源码：MasterChief
4. Nuget：Install-Package MasterChief.DotNet.Core.KafkaLog
5. 欢迎Star，欢迎Issues；

源码#

1. 基于Log4Net来实现与kafka通讯Appender

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   public class KafkaAppender : AppenderSkeleton { #region Fields /// <summary> /// Kafka 生产者 /// </summary> private Producer _kafkaProducer; #endregion Fields #region Properties /// <summary> /// Brokers /// </summary> public string Brokers { get; set; } /// <summary> /// Topic /// </summary> public string Topic { get; set; } #endregion Properties #region Methods /// <summary> /// Initialize the appender based on the options set /// </summary> /// <remarks> /// <para> /// This is part of the <see cref="T:log4net.Core.IOptionHandler" /> delayed object /// activation scheme. The <see cref="M:log4net.Appender.AppenderSkeleton.ActivateOptions" /> method must /// be called on this object after the configuration properties have /// been set. Until <see cref="M:log4net.Appender.AppenderSkeleton.ActivateOptions" /> is called this /// object is in an undefined state and must not be used. /// </para> /// <para> /// If any of the configuration properties are modified then /// <see cref="M:log4net.Appender.AppenderSkeleton.ActivateOptions" /> must be called again. /// </para> /// </remarks> public override void ActivateOptions() { base.ActivateOptions(); InitKafkaProducer(); } /// <summary> /// Subclasses of <see cref="T:log4net.Appender.AppenderSkeleton" /> should implement this method /// to perform actual logging. /// </summary> /// <param name="loggingEvent">The event to append.</param> /// <remarks> /// <para> /// A subclass must implement this method to perform /// logging of the <paramref name="loggingEvent" />. /// </para> /// <para> /// This method will be called by <see cref="M:DoAppend(LoggingEvent)" /> /// if all the conditions listed for that method are met. /// </para> /// <para> /// To restrict the logging of events in the appender /// override the <see cref="M:PreAppendCheck()" /> method. /// </para> /// </remarks> protected override void Append(LoggingEvent loggingEvent) { try { var message = GetLogMessage(loggingEvent); var topic = GetTopic(loggingEvent); _ = _kafkaProducer.SendMessageAsync(topic, new[] {new Message(message)}); } catch (Exception ex) { ErrorHandler.Error("KafkaProducer SendMessageAsync", ex); } } /// <summary> /// Raises the Close event. /// </summary> /// <remarks> /// <para> /// Releases any resources allocated within the appender such as file handles, /// network connections, etc. /// </para> /// <para> /// It is a programming error to append to a closed appender. /// </para> /// </remarks> protected override void OnClose() { base.OnClose(); StopKafkaProducer(); } private string GetLogMessage(LoggingEvent loggingEvent) { var builder = new StringBuilder(); using (var writer = new StringWriter(builder)) { Layout.Format(writer, loggingEvent); if (Layout.IgnoresException && loggingEvent.ExceptionObject != null) writer.Write(loggingEvent.GetExceptionString()); return writer.ToString(); } } private string GetTopic(LoggingEvent loggingEvent) { return string.IsNullOrEmpty(Topic) ? Path.GetFileNameWithoutExtension(loggingEvent.Domain) : Topic; } /// <summary> /// 初始化Kafka 生产者 /// </summary> private void InitKafkaProducer() { try { if (string.IsNullOrEmpty(Brokers)) Brokers = "http://localhost:9200"; if (_kafkaProducer == null) { var brokers = new Uri(Brokers); var kafkaOptions = new KafkaOptions(brokers) { Log = new KafkaLog() }; _kafkaProducer = new Producer(new BrokerRouter(kafkaOptions)); } } catch (Exception ex) { ErrorHandler.Error("InitKafkaProducer", ex); } } /// <summary> /// 停止生产者 /// </summary> private void StopKafkaProducer() { try { _kafkaProducer?.Stop(); } catch (Exception ex) { ErrorHandler.Error("StopKafkaProducer", ex); } } #endregion Methods }

2. 基于之前定义接口，来实现kafkaLogService

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   public sealed class KafkaLogService : ILogService { #region Constructors /// <summary> /// Initializes the <see cref="FileLogService" /> class. /// </summary> static KafkaLogService() { KafkaLogger = LogManager.GetLogger(KafkaLoggerName); } #endregion Constructors #region Fields /// <summary> /// Kafka logger name /// </summary> public const string KafkaLoggerName = "KafkaLogger"; /// <summary> /// Kafka logger /// </summary> public static readonly ILog KafkaLogger; #endregion Fields #region Methods /// <summary> /// Debug记录 /// </summary> /// <param name="message">日志信息</param> public void Debug(string message) { if (KafkaLogger.IsDebugEnabled) KafkaLogger.Debug(message); } /// <summary> /// Debug记录 /// </summary> /// <param name="message">日志信息</param> /// <param name="ex">异常信息</param> public void Debug(string message, Exception ex) { if (KafkaLogger.IsDebugEnabled) KafkaLogger.Debug(message, ex); } /// <summary> /// Error记录 /// </summary> /// <param name="message">日志信息</param> public void Error(string message) { if (KafkaLogger.IsErrorEnabled) KafkaLogger.Error(message); } /// <summary> /// Error记录 /// </summary> /// <param name="message">日志信息</param> /// <param name="ex">异常信息</param> public void Error(string message, Exception ex) { if (KafkaLogger.IsErrorEnabled) KafkaLogger.Error(message, ex); } /// <summary> /// Fatal记录 /// </summary> /// <param name="message">日志信息</param> public void Fatal(string message) { if (KafkaLogger.IsFatalEnabled) KafkaLogger.Fatal(message); } /// <summary> /// Fatal记录 /// </summary> /// <param name="message">日志信息</param> /// <param name="ex">异常信息</param> public void Fatal(string message, Exception ex) { if (KafkaLogger.IsFatalEnabled) KafkaLogger.Fatal(message, ex); } /// <summary> /// Info记录 /// </summary> /// <param name="message">日志信息</param> public void Info(string message) { if (KafkaLogger.IsInfoEnabled) KafkaLogger.Info(message); } /// <summary> /// Info记录 /// </summary> /// <param name="message">日志信息</param> /// <param name="ex">异常信息</param> public void Info(string message, Exception ex) { if (KafkaLogger.IsInfoEnabled) KafkaLogger.Info(message, ex); } /// <summary> /// Warn记录 /// </summary> /// <param name="message">日志信息</param> public void Warn(string message) { if (KafkaLogger.IsWarnEnabled) KafkaLogger.Warn(message); } /// <summary> /// Warn记录 /// </summary> /// <param name="message">日志信息</param> /// <param name="ex">异常信息</param> public void Warn(string message, Exception ex) { if (KafkaLogger.IsWarnEnabled) KafkaLogger.Warn(message, ex); } #endregion Methods }

3. 修改Log4Net.Config，定义Kafka的Topic以及Brokers

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   <appender name="KafkaAppender" type="MasterChief.DotNet.Core.KafkaLog.KafkaAppender, MasterChief.DotNet.Core.KafkaLog"> <param name="Topic" value="beats" /> <param name="Brokers" value="http://localhost:9092" /> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="发生时间：%date %newline事件级别：%-5level %newline事件来源：%logger%newline日志内容：%message%newline" /> </layout> </appender>

使用#

1. 由于基于上篇说的日志接口，所以可以通过Ioc切换，而且不影响在业务代码调用；
2. 基于业务需求，您可以同时落地本地日志，保证网络抖动或者不正常的时候能够正常记录日志；

结语#

1. 小弟不才，大佬轻拍；