ASP.NET Core with Application Insights

Add Azure Application Insights to your ASP.NET Core webapplication

In this lab, you will learn how to:

• Create a default ASP.NET Core webapplication
• Publish the webapplication to Azure
• Add Application Insights
• Add tracing information

Create a default ASP.NET Core webapplication

1. Start Visual Studio 2017 and hit CTRL+SHIFT+N to create a new project (or click File/New/Project)

2. In the 'New Project' view, select .NET Core under Visual C# and on the right select ASP.NET Core Web Application.

3. Enter a name for your project and click OK.

   

4. As a Template select Web Application and make sure the authentication is set to No authentication. Finish the project creation by clicking OK.

   

5. Build (CTRL+SHIFT+B) and run (F5) the application to make sure everything is working. If everything is OK the web application should show up in your predefined browser with a title identical to the name of the project you set earlier.

   

6. You just created a full ASP.NET Core webapplication. It's as simple as that. Next up. Publishing this webapplication to Azure.

Publish the webapplication to Azure

1. If the application is still running in debug, now is the time so stop it (either close the browser or in Visual Studio hit SHIFT+F5)

2. In the Solution Explorer (hit CTRL+W,S to view the Solution Explorer) right click on the project and select Publish from the context menu.

   

3. Next select Microsoft Azure App Service and select Create New before hitting the Publish button.

   

4. In the Create Ap Service screen you have to set a unique App Name value as this will be part of url. Also make sure to select the correct type of App Service being Web App. For this demo it's best to change the App Serivce Plan to a Free plan so there won't be any additional charges involved.

   

5. When you press 'Create' the application is being deployed to Azure, which takes a few minutes. After a while your browser will open and show you the web application online.

   

Add Application Insights

1. In the Solution Explorer (hit CTRL+W,S to view the Solution Explorer) right click on the project and select Configure Application Insights from the context menu.

   

2. In the Application Insights view click the Start Free button.

   

3. Click on the Configure settings link to change the default settings to your liking. Selecting preferred resources groups and account to use.

   !! Don't forget to change the plan settings to halt data collection when the limit is reached. This is not set by default this way!!

   

4. Click Register to start the Application Insights configuration. When it's done (it takes a moment so relax) press Finish to continue. You should now see a screen which states: Configured: 100%.

5. Before we can actually see some information we need to publish the appication to Azure again. There right click the project in the Solution Explorer and select Publish again.

6. As we published the application earlier on we can now simply press the Publish button. This will first build the application and then it will be published to Azure again.

   

7. Now open the Azure Portal and navigate to All Resources.

8. Type insight in the All Resources search bar to search for the Application Insights which we just created.

   

9. Open the purple (the one with the purple lamp icon) Application Insights node.

10. Now you can see that you application is actually handling requests and you can also view response times and lots of other interesting data.

    

Add Tracing information

If you want more than just some request and response times you can add some tracing to you application.

1. Open Startup.cs and add the following line of code to the Configure() function:

   loggerFactory.AddApplicationInsights(app.ApplicationServices, LogLevel.Information);

   The Configure() function should start somewhat like this:

2. Now open HomeController.cs.

3. On line 12 (which is the first line within the HomeController class) type ctor followed by a tab. This will automatically create the HomeController constructor for you. (you just used a Visual Studio code snippet)

4. Append the following using: using Microsoft.Extensions.Logging;

5. Now before the HomeController constructor create a private ILogger property called "_logger".

6. Modify the constructor in such a way that it takes a ILogger<HomeController> named logger and sets this logger object to the previously defined _logger property.

7. The HomeController constructor should end up like this:

   public class HomeController : Controller
   {
   	private ILogger _logger;
   
   	public HomeController(ILogger<HomeController> logger)
   	{
   		_logger = logger;
   	}

8. Finally we write a warning in the log whenever someone opens the About page. To do this navigate to the About() function within the HomeController and add the following line of code to the start of the function:

   _logger.LogWarning("SOMEBODY OPENED THE ABOUT PAGE!!");

9. Now save the changes and publish the web application again. (Right click on the project within the Solution Explorer, click Publish followed by the Publish button)

10. After publish is succeeded the webbrowser opens the webapplication in Azure. Now click About in the application menu to go to the About page of your application.

11. You can view the Trace information from within Visual Studio by using the Application Insights menu. You can find this menu by right clicking next to the Help menu. This will open a context menu where you can select Application Insights.

    

12. This should bring up the Application Insights menu button (obviously the notification number may vary):

    

13. Click on the Application Insights button to bring up a context menu and select Search Telemetry

    

14. In the Application Insights Search window set the Time range to Last 30 minutes and hit the Search button (it's the magnifying glass icon)

15. When you scroll down the results you should be able to find the warning which you just created:

    

And that's all there is to it.

Summary

By completing this lab you have learned how to create and publish a basic Azure ASP.NET Core application. You've also learning how to setup Application Insights for your application and finally you wrote your own trace line to the cloud!

For more information about Application Insights, please check out docs.microsoft.com