Integrating NLog with Stackdriver for error reporting on Google Cloud

In this post I will create a .net core console app, which will be hosted on Google Cloud Compute Engine VM running Debian Linux console only OS. For this we are going to use Google.Cloud.Logging.NLog .NET client library to integrate Google Stackdriver Logging with NLog. The sample code for this app is hosted on github repository.

Lets create our .Net Core console app project

>mkdir nlog_with_stackdriver
>cd nlog_with_stackdriver
>dotnet new console

Run 'dotnet build' and 'dotnet run' to see if our new project builds and runs successfully.

Now we need to add NLog and  Google.Cloud.Logging.NLog packages.

>dotnet add package nlog
>dotnet add package Google.Cloud.Logging.NLog packages

Create nlog.config file

	<?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"
	internalLogLevel="info">
	<extensions>
	<add assembly="Google.Cloud.Logging.NLog"/>
	</extensions>
	<!-- the targets to write to -->
	<targets>
	<target name="asyncConsole" xsi:type="AsyncWrapper">
	<target name="console"
	xsi:type="ColoredConsole"
	layout="${date} ${threadname:whenEmpty=${threadid}} ${level:uppercase=true} ${logger} ${message} ${onexception:${exception}}" />
	</target>
	<target name="asyncStackDriver" xsi:type="AsyncWrapper">
	<target name="stackDriver"
	xsi:type="GoogleStackdriver"
	logId="Default"
	layout="${longdate}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" />
	</target>
	</targets>
	<!-- rules to map from logger name to target -->
	<rules>
	<!--All logs-->
	<logger name="*" minlevel="Trace" writeTo="asyncConsole" />
	<logger name="*" minlevel="Trace" writeTo="asyncStackDriver" />
	<logger name="Microsoft.*" maxLevel="Info" final="true" /> <!-- BlackHole without writeTo -->
	</rules>
	</nlog>

view raw nlog_stackdriver.config hosted with ❤ by GitHub

Important to note the use of assembly Google.Cloud.Logging.NLog and in asyncStackDriver target I used logId as "Default". LogId can be set to be the name of the console app or the project.

In the project file include ItemGroup to copy nlog.config file to output directory during build and publish.

	<ItemGroup>
	<None Include="nlog.config" CopyToOutputDirectory="Always" />
	<ItemGroup>

view raw copy_to_output_dir.csproj hosted with ❤ by GitHub

Add the following code to Main.

	static void Main(string[] args)
	{
	Logger logger = LogManager.GetCurrentClassLogger();
	// Log some information. This log entry will be sent to Google Stackdriver Logging.
	logger.Info("An exciting log entry for Google Cloud!");
	// Flush buffered log entries before program exit; then shutdown the logger before program exit.
	LogManager.Flush(TimeSpan.FromSeconds(15));
	LogManager.Shutdown();
	}

view raw nlog_with_stackdriver_Main.cs hosted with ❤ by GitHub

At the end of the program before closing it is important to Flush resources and Shutdown the logger. Windows 10 gives limited time for application to close and under linux as well as Windows important to clear and close external resources used. In our case we are using Google Cloud Logging Agent.

Now our sample app is competed and ready to deploy to Google Cloud Computer Engine VM. Looks like it should just magically work. We do not need provide any authentication with Google Cloud, nor we do not need to specify project ID in nlog.config. When running from within Compute Engine VM Google.Cloud.Logging.NLog will detect all needed settings and just run. But here is a catch...

We need to install Google Cloud Logging Agent on our Debian virtual machine.

>curl -sSO https://dl.google.com/cloudagents/install-logging-agent.sh
>sudo bash install-logging-agent.sh

References:

• Google.Cloud.Logging.NLog
• Stackdriver Agent
• Google Cloud Logging NLog target
• NLog Configuration Options
• NLog Best Practice