How to log using NLog directly to Datadog

Question

Using Nlog to log from my asp.net Core application, I would like to review the logs in Datadog.

Datadog allows me to visualize the log data, and slice, search, select and sort logs in a convenient way to provide support to my customers.

I was looking for a way to use NLog to directly post to the Datadog API, so I do not need to use the Windows Agent to collect the logs.

Below how to do this, as I could not find the answer anywhere.

Answer 1

In Datadog, create an API key in Integrations, APIs. Give the API key a name.

In NLog.config create a target. The url is either datadoghq.com or datadoghq.eu (for europe).

 <target xsi:type="WebService"
        name="datadog"
        url="https://http-intake.logs.datadoghq.com/v1/input"
        encoding="utf-8"
        protocol="JsonPost"
        preAuthenticate="false" >
        <parameter name='date' type='System.String' layout='${longdate}'/> 
        <parameter name='ipaddress' type='System.String' layout='${aspnet-request-ip}'/>
        <parameter name="userid" type='System.String' layout="${aspnet-User-Identity}" />
        <parameter name="level"  type='System.String'  layout="${level:upperCase=true}"/>
        <parameter name="version" type='System.String'  layout="${configsetting:name=VersionSettings.Version:default=?}" />
        <parameter name="threadid"  type='System.String' layout="${threadid}" />
        <parameter name="controller"  type='System.String' layout="${aspnet-mvc-controller}" />
        <parameter name="class" type='System.String'  layout="${callsite:className=True:includeNamespace=False:fileName=False:includeSourcePath=False:methodName=True:cleanNamesOfAnonymousDelegates=True:cleanNamesOfAsyncContinuations=True}" />
        <parameter name="message" type='System.String'  layout="${message}" />
        <parameter name="elapsed"  type='System.String' layout ="${event-properties:item=elapsed}" />
        <parameter name="service"  type='System.String' layout="${configsetting:name=Nlog.Component}" />
        <parameter name="hostname"  type='System.String' layout="${configsetting:name=Nlog.HostName}" />
        <parameter name="exception"  type='System.String' layout="${exception:format=ToString}" />
        <parameter name="ddsource"  type='System.String' layout="csharp" />
        <header name="DD-API-KEY" layout="${configsetting:name=Nlog.datadog}"/>
        <header name="Content-Type" layout="application/json"/>
</target>       

Now create a rule to write to the target and you are done!

All of the parameters can be configured to become columns in Datadog, and/or facets to select on. I am using a date parameter so that the date matches other logs, rather than displaying the built in date.