NLog.Web.AspNetCore.Targets.Gelf

Gelf4NLog is an NLog target implementation to push log messages to GrayLog2. It implements the Gelf specification and communicates with GrayLog server via UDP.

History

Code forked from https://github.com/2020Legal/NLog.Targets.Gelf which is a fork from https://github.com/akurdyukov/Gelf4NLog who forked the origonal code from https://github.com/seymen/Gelf4NLog

I transformed the project to .NET Core.

Usage

Use Nuget:

$ dotnet add package NLog.Web.AspNetCore.Targets.Gelf

Configuration

Here is a sample nlog.config configuration file for graylog:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off"
      internalLogFile="c:\temp\internal-nlog.txt">
  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
    <add assembly="NLog.Web.AspNetCore.Targets.Gelf"/>
  </extensions>
  <targets>
    <target xsi:type="File" name="debugFile" filename="C:\@Logs\${shortdate}-${level}-${applicationName}.txt" layout="${longdate}|${level:upperCase=true}|${logger}|${aspnet-Request-Method}|url: ${aspnet-Request-Url}${aspnet-Request-QueryString}|${message}" concurrentWrites="false" />
    <target xsi:type="Gelf" name="graylog" endpoint="udp://192.168.99.100:12201" facility="console-runner" sendLastFormatParameter="true" gelfVersion="1.1">
	
	<!-- Optional parameters -->
	<parameter name="param1" layout="${longdate}"/>
	<parameter name="param2" layout="${callsite}"/>
    </target>
  </targets>
  <rules>
    <logger name="*" minlevel="Debug" writeTo="debugFile, graylog" />
  </rules>
</nlog>

Options are the following:

• name: arbitrary name given to the target
• xsi:type: set this to "gelf"
• endpoint: the uri pointing to the graylog2 input in the format udp://{IP or host name}:{port} note: support is currently only for udp transport protocol
• facility: The graylog2 facility to send log messages
• sendLastFormatParameter: default false. If true last parameter of message format will be sent to graylog as separate field per property
• gelfVersion: default "1.0". Set this to "1.1" in order to use actual GELF message format

###Code

//excerpt from ConsoleRunner
var eventInfo = new LogEventInfo
				{
					Message = comic.Title,
					Level = LogLevel.Info,
				};
eventInfo.Properties.Add("Publisher", comic.Publisher);
eventInfo.Properties.Add("ReleaseDate", comic.ReleaseDate);
Logger.Log(eventInfo);

or alternatively for simple log messages

Logger.Info("Simple message {0}", value);

or alternatively for use of sendLastFormatParameter

Logger.Info(comic.Title, new { Publisher = comic.Publisher, ReleaseDate = comic.ReleaseDate });

will log Publisher and ReleaseDate as separate fields in Graylog