Continuous Delivery with TFS / VSTS – Instrument for Telemetry with Application Insights

If you get to the stage where you are deploying your application on a very frequent basis and you are relying on automated tests for the bulk of your quality assurance then a mechanism to alert you when things go wrong in production is essential. There are many excellent tools that can help with this however anyone working working with ASP.NET websites (such as the one used in this blog series) and who has access to Azure can get going very quickly using Application Insights. I should qualify that by saying that whilst it is possible to get up-and-running very quickly with Application Insights there is a bit more work to do to make Application Insights a useful part of a continuous delivery pipeline. In this post in my blog series on Continuous Delivery with TFS / VSTS we take a look at doing just that!

The Big Picture

My aim in this post is to get telemetry from the Contoso University sample ASP.NET application running a) on my developer workstation, b) in the DAT environment and c) in the DQA environment. I’m not bothering with the PRD environment as it’s essentially the same as DQA. (If you haven’t been following along with this series please see this post for an explanation of the environments in my pipeline.) I also want to configure my web servers running IIS to send server telemetry to Azure.

Azure Portal Configuration

The starting point is some foundation work in Azure. We need to create three Application Insights resources inside three different resource groups representing the development workstation, the DAT environment and the DQA environment. A resource group for the development workstation doesn’t exist so the first step is to create a new resource group called PRM-DEV. Then create three Application Insights resources in each of the resource groups – I used the same names as the resource groups. For the DAT environment for example:

The final result should look something like this (note I added the resource group column in to the table):

Add the Application Insights SDK

With the Azure foundation work out of the way we can now turn our attention to adding the Application Insights SDK to the Contoso University ASP.NET application. (You can get the starting code from my GitHub repository here.) Application Insights is a NuGet package but it can be added by right-clicking the web project and choosing Add Application Insights Telemetry:

You are then presented with a configuration dialog which will allow you to select the correct Azure subscription and then the Application Insights resource – in this case the one for the development environment:

You can then run Contoso University and see telemetry appear in both Visual Studio and the Azure portal. There is a wealth of information available so do explore the links to understand the extent.

Configure for Multiple Environments

As things stand we have essentially hard-coded Contoso University with an instrumentation key to send telemetry to just one Application Insights resource (PRM-DEV). Instrumentation keys are specific to one Application Insights resource so if we were to leave things as they are then a deployment of the application to the delivery pipeline would cause each environment to send its telemetry to the PRM-DEV Application Insights resource which would cause utter confusion. To fix this the following procedure can be used to amend an ASP.NET MVC application so that an instrumentation key can be passed in as a configuration variable as part of the deployment process:

1. Add an iKey attribute to the appSettings section of Web.config (don’t forget to use your own instrumentation key value from ApplicationInsights.config):
   

   <appSettings>
     <!-- Other settings here -->
     <add key="iKey" value="8fc11978-dd5b-7b87-addc-965329534108"/>
   </appSettings>

2. Add a transform to Web.Release.config that consists of a token (__IKEY__) that can be used by Release Management:
   

   <appSettings>
     <add key="iKey" value="__IKEY__" xdt:Transform="SetAttributes" xdt:Locator="Match(key)"/>
   </appSettings>

3. Add the following code to Application_Start in Global.asax.cs:
   

   Microsoft.ApplicationInsights.Extensibility.TelemetryConfiguration.Active.InstrumentationKey = System.Web.Configuration.WebConfigurationManager.AppSettings["iKey"];

4. As part of the Application Insights SDK installation Views.Shared._Layout.cshtml is altered with some JavaScript that adds the iKey to each page. This isn’t dynamic and the JavaScript instrumentationKey line needs altering to make it dynamic as follows:
   

   instrumentationKey: "@Microsoft.ApplicationInsights.Extensibility.TelemetryConfiguration.Active.InstrumentationKey"

5. Remove or comment out the InstrumentationKey section in ApplicationInsights.config.

As a final step run the application to ensure that Application Insights is still working. The code that accompanies this post can be downloaded from my GitHub account here.

Amend Release Management

As things stand a release build of Contoso University will have a tokenised appSettings key in Web.config as follows:

<add key="iKey" value="__IKEY__" />

When the build is deployed to the DAT and DQA environments the __IKEY__ token needs replacing with the instrumentation key for the respective resource group. This is achieved as follows:

1. In the ContosoUniversity release definition click on the ellipsis of the DAT environment and choose Configure Variables. This will bring up a dialog to add an InstrumentationKey variable:
   
2. The value for InstrumentationKey can be copied from the Azure portal. Navigate to Application Insights and then to the resource (PRM-DAT in the above screenshot) and then Configure > Properties where Instrumentation Key is to be found.
3. The preceding process should be repeated for the DQA environment.
4. Whilst still editing the release definition, edit the Website configuration tasks of both environments so that the Deployment > Scrip Arguments field takes a new parameter at the end called $(InstrumentationKey):
   
   
5. In Visual Studio with the ContosoUniversity solution open, edit ContosoUniversity.Web.Deploy.Website.ps1 to accept the new InstrumentationKey as a parameter, add it to the $configurationData block and to use it in the ReplaceWebConfigTokens DSC configuration:
   

   xTokenize ReplaceWebConfigTokens
   {
       Recurse = $false
       Tokens = @{DATA_SOURCE = $Node.SqlServerName; INITIAL_CATALOG = "ContosoUniversity"; IKEY = $Node.InstrumentationKey}
       UseTokenFiles = $false
       Path = "C:\temp\website"
       SearchPattern = "web.config"
   }

6. Check in the code changes so that a build and release are triggered and then check that the Application Insights resources in the Azure portal are displaying telemetry.

Install Release Annotations

A handy feature that became available in early 2016 was the ability to add Release Annotations, which is a way to identify releases in the Application Insights Metrics Explorer. Getting this set up is as follows:

1. Release Annotations is an extension for VSTS or TFS 2015.2 and later and needs to be installed from the marketplace via this page. I installed it for my VSTS account.
2. In the release definition, for each environment (I’m just showing the DAT environment below) add two variables – ApplicationId and ApiKey but leave the window open for editing:
   
3. In a separate browser window, navigate to the Application Insights resource for that environment in the Azure portal and then to the API Access section.
4. Click on Create API key and complete the details as follows:
   
5. Clicking Generate key will do just that:
   
6. You should now copy the Application ID value hand API key value (both highlighted in the screenshot above) to the respective text boxes in the browser window where the release definition environment variables window should still be open. After marking the ApiKey as a secret with the padlock icon this window can now be closed.
7. The final step is to add a Release Annotation task to the release definition:
   
8. The Release Annotation is then edited with the ApplicationId and ApiKey variables:
   
9. The net result of this can be seen in the Application Insights Metrics Explorer following a successful release where the release is displayed as a blue information icon:
   
10. Clicking the icon opens the Release Properties window which displays rich details about the release.

Install the Application Insights Status Monitor

Since we are running our web application under IIS even more telemetry can be gleaned by installing the Application Insights Status Monitor:

1. On the web servers running IIS download and install Status Monitor.
2. Sign in to your Azure account in the configuration dialog.
3. Use Configure settings to choose the correct Application Insights resource.
4. Add the domain account the website is running under (via the application pool) to the Performance Monitor Users local security group.

The Status Monitor window should finish looking something like this:

See this documentation page to learn about the extra telemetry that will appear.

Wrapping Up

In this post I’ve only really covered configuring the basic components of Application Insights. In reality there’s a wealth of other items to configure and the list is bound to grow. Here’s a quick list I’ve come up with to give you a flavour:

• Web Availability Tests
• Integration with Glimpse
• Metrics widget for VSTS dashboards
• Track analytics queries in Azure dashboards

This list however doesn’t include the huge number of options for configuring Application Insights itself. There’s enough to keep anyone interested in this sort of thing busy for weeks. The documentation is a great starting point – check out the sidebar here.

Cheers – Graham

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