How can I register CorrelationManager.ActivityId using NLog

Question

How can I register CorrelationManager.ActivityIdas a separate field?

Here is my current NLog.config:

<?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">

  <variable name="logDirectory" value="${basedir}/Logs" />

  <extensions>
    <add assembly="NLog.Mongo"/>
  </extensions>

  <targets>
    <target xsi:type="Mongo"
            name="mongoCustom"
            includeDefaults="false"
            connectionString="mongodb://localhost/FooLogging"
            collectionName="authLogs">

      <field name="Date" layout="${longdate:universalTime=true}" />
      <field name="Level" layout="${level}"/>
      <field name="Message" layout="${message}" />
      <field name="Logger" layout="${logger}"/>
      <field name="Exception" layout="${exception:format=tostring}" />
      <field name="ThreadID" layout="${threadid}" />
      <field name="ThreadName" layout="${threadname}" />
      <field name="ProcessID" layout="${processid}" />
      <field name="ProcessName" layout="${processname:fullName=true}" />
      <field name="UserName" layout="${windows-identity}" />
    </target>
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="mongoCustom" />
  </rules>
</nlog>

Answer 1

There is currently no built-in support CorrelationManager.ActivityId.

However, you can create your own layout that displays it:

[LayoutRenderer("activityid")]
public class ActivityIdLayoutRenderer : LayoutRenderer
{
    protected override void Append(StringBuilder builder, LogEventInfo logEvent)
    {
        builder.Append(Trace.CorrelationManager.ActivityId.ToString());
    }
}

You also need to register it with:

 ConfigurationItemFactory.Default.LayoutRenderers
      .RegisterDefinition("activityid", typeof(ActivityIdLayoutRenderer));

Then you can use it in your target definition with:

<target xsi:type="Mongo">
      <!-- ... -->
      <field name="ActivityId" layout="${activityid}" />
</target>

, ActivityID, , - .

Answer 2

${activityid} NLog v4.1. https://github.com/nlog/nlog/wiki/Trace-Activity-Id-Layout-Renderer