NLog.GelfLayout

GelfLayout is a custom layout renderer for NLog to format log meessages as GELF Json structures.

Usage

Install from Nuget

PM> Install-Package NLog.GelfLayout

Please note that the NuGet package (at the moment) is only compiled for the latest .Net framework 4.5.

NLog Configuration

1. Add <add assembly="NLog.Layouts.GelfLayout" /> to <extensions> element in NLog.config
2. Set layout="${gelf:facility=MyFacility}" attribute for target element

Sample Usage with RabbitMQ Target

You can configure this layout for NLog Targets that respect Layout attribute. For instance the following configuration writes log messages to a RabbitMQ Exchange in GELF format.

<?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" 
      xmlns:haf="https://github.com/haf/NLog.RabbitMQ/raw/master/src/schemas/NLog.RabbitMQ.xsd" >
  <extensions>
    <add assembly="NLog.Targets.RabbitMQ" />
    <add assembly="NLog.Layouts.GelfLayout" />
  </extensions>
  
  <targets async="true">
    <target name="RabbitMQTarget"
            xsi:type="RabbitMQ"
            hostname="mygraylog.mycompany.com"
            exchange="logmessages-gelf"
            durable="true"
            useJSON="false"
            layout="${gelf:facility=MyFacility}"
    />
  </targets>

  <rules>
    <logger name="*" minlevel="Debug" writeTo="RabbitMQTarget" />
  </rules>
</nlog>

In this example there would be a Graylog2 server that consumes the queued GELF messages.

Credits

GELF converter module is all taken from Gelf4NLog by Ozan Seymen