Wsrtjtyk

I've seen a couple extensions for log4net that claim to create json to the log file, but the format is never valid json, meaning the collection is not in an array and not coma separated. Am I using it wrong or is there just no way to use log4net with json?

<appender name="SessionFileAppender" type="log4net.Appender.FileAppender">

  <file value="Session.log" />

  <appendToFile value="false" />

  <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />

  <layout type='log4net.Layout.SerializedLayout, log4net.Ext.Json'>

    <decorator type='log4net.Layout.Decorators.StandardTypesDecorator, log4net.Ext.Json' />

    <default />

    <remove value='message' />

    <member value='message:messageobject' />

  </layout>

</appender>

Output is:

{"date":"2017-01-29T13:45:50.7345813-05:00","level":"DEBUG","appname":"MyApp.vshost.exe","logger":"MainWindow","thread":"9","ndc":"(null)","message":"Loading new UI instance"}

{"date":"2017-01-29T13:45:50.7380842-05:00","level":"DEBUG","appname":"MyApp.vshost.exe","logger":"MainWindow","thread":"9","ndc":"(null)","message":"Loading internal localization file"}

{"date":"2017-01-29T13:45:50.7510970-05:00","level":"DEBUG","appname":"MyApp.vshost.exe","logger":"MainWindow","thread":"9","ndc":"(null)","message":"Initializing UI"}

which is close, but not really valid json.

download log4net.Ext.Json nuget package

add following config settings to app.config/web.config files

<log4net>

<appender name="RollingFile" type="log4net.Appender.RollingFileAppender">

  <file value="logslog-file-name.json" />

  <rollingStyle value="Date" />

  <datePattern value="yyyy-MM-dd" />

  <PreserveLogFileNameExtension value="true" />

  <staticLogFileName value="false" />

  <appendToFile value="true" />

  <maxSizeRollBackups value="10" />

  <dateTimeStrategy 

  type="log4net.Appender.RollingFileAppender+UniversalDateTime" />



  <!--text formatted log4net logging-->

  <!--<layout type="log4net.Layout.PatternLayout">

    --><!--check conversion patterns from 

   https://logging.apache.org/log4net/--><!--

    --><!--<conversionPattern value="%utcdate{ABSOLUTE} UTC %c{1} - %m%n" 

  />--><!--

    <conversionPattern value="%date [%thread] %-5level %logger - 

  %message%newline" />

  </layout>-->



  <!--json formatted log4net logging-->

  <layout type="log4net.Layout.SerializedLayout, log4net.Ext.Json">

    <decorator type="log4net.Layout.Decorators.StandardTypesDecorator, 

  log4net.Ext.Json" />

    <member value="date:date" />

    <member value="level:level" />

    <member value="logger:logger" />

    <member value="message:messageObject" />

    <member value="exception:exception" />

  </layout>

</appender>

<root>

  <!--Options are "ALL", "DEBUG", "INFO", "WARN", "ERROR", "FATAL" and 

"OFF".-->

  <level value="DEBUG" />

  <appender-ref ref="RollingFile" />

</root>

</log4net>

here is a sample call with ninject

Kernel = new StandardKernel(); 

Kernel.Bind<ILog>().ToMethod(c => 

LogManager.GetLogger(typeof(YourClassName))).InSingletonScope();

var log = Kernel.Get<ILog>();

log.debug("testing log4net json");

The solution is basic enough, I wrote my own Appender that stored data in a collection, then serialized the collection with Json.net as needed. This also gives me the ability to view the log in the app and bind to it aswell so added bonus.

public class CollectionAppender : AppenderSkeleton

{

    public static ObservableCollection<LogItem> logData = new ObservableCollection<LogItem>();

    protected override void Append(LoggingEvent loggingEvent)

    {

        logData.Add(new LogItem(loggingEvent));

    }

}



public class LogItem

{

    public string Logger { get; private set; }

    public string Level { get; private set; }

    public string Message { get; private set; }

    public DateTime Timestamp { get; private set; }

    public Exception ExceptionData { get; private set; }



    public bool ShouldSerializeExceptionData() //This keeps things tidy when using Json.net for non exemption entries.

    {

        return ExceptionData != null;

    }



    public LogItem(LoggingEvent data)

    {

        Logger = data.LoggerName;

        Level = data.Level.DisplayName;

        Message = data.RenderedMessage;

        Timestamp = data.TimeStamp;

        ExceptionData = data.ExceptionObject;

    }

}

It outputs each line as separate JSON record, as it does with 1 line logs.
You can take line by line and parse, or you can add your surrounding and a comman after each } and that would do it.

Yes, do this in the log4net.config file.

    <conversionPattern



        value="{&quot;EntryDate&quot;:&quot;%date{ddd MMM dd HH:mm:ss zzz yyyy}&quot;,



        &quot;Level&quot;:&quot;%level&quot;,



        &quot;Logger&quot;:&quot;%logger&quot;,



        &quot;Message&quot;:&quot;%message&quot;}



        %newline" />