Deploy ASP.NET Core 3 Previews to Azure App Using Extensions

A few weeks ago when the post Deploy ASP.NET Core 3 Previews to Azure App Service I got an email from Jerrie Pelser who pointed out that there are extensions available for App Service that allow usage of the public previews of ASP.NET Core 3 without having to do a self-contained deployment.

In addition to Jerrie’s suggestion pajaybasu pointed out in this Reddit post that using Docker is another option. Pajaybasu also pointed out a line in the original post where I that self-contained deployments were the only option which of course was incorrect.

The first half of this post is going to be the same as the original post which covers the creation and the initial publication to Azure App Service. The last half will cover using an extension to enable the preview version of ASP.NET Core.

Sample Application

I used the following .NET CLI command to create a new ASP.NET Core application using React for its front end.

dotnet new react

After the creation process is complete open the project in Visual Studio. I highly recommend using the Visual Studio 2019 preview release when working with any .NET Core 3 applications.

Publish to App Service

In Visual Studio’s Solution Explorer right click on the project file and select Publish.

Select App Service for the publish target. Here we are creating a new app service. Next, click Publish.

The next dialog if the information about the new App Service that will be created. I took the defaults for the most part. I did create a new resource group for this application to make the resources easier to clean up in the future. I also changed the hosting plan to the free tier. Click Create to continue.

The Error and the Warning

As part of the publishing process, a browser will be opened to the address of the application. When this happens you will see an error about ANCM In-Process Handler Load Failure (if you are using IIS In-Process Hosting).

If you look back at Visual Studio you will see the following warning that your application requires the .NET Core runtime 3.0 and App Service only supports up to 2.2. Since we are going to fix this in App Service I recommend selecting Don’t perform check in the future (only this profile).

Another Fix

For this version of the fix, go to your App Service in the Azure Portal. In the menu under the Development Tools select the Extensions option.

On the next page click the Add button at the top. Click on the Choose Extension and select the ASP.NET Core 3.0 (x86) Runtime option.

Next, click Legal Terms, read the terms and if you are OK with the terms then click the OK button. You will then have to click OK on the add extension blade which will start the extension installation.

If you were to load your site at this point you would still get the 500 error. Under Settings click the Configuration and click on General settings turn Web sockets On and click Save.

At this point, your site should be working. You can also go back and turn web sockets back off and the site will continue working. I have no idea what toggling web sockets does to make everything start working, but thanks to this comment on a GitHub issue for the key to getting this working.

Wrapping Up

Hopefully, between this post and the previous one using a self-contained deployment, you won’t have any issues trying out the .NET Core 3 with App Service.

Add Application Insights to an Existing ASP.NET Core Application

I have been using Azure’s App Service to host the web applications I am playing around with for a few years now. The service makes it simple to get an application hosted. Today I decided to try out Application Insights which is an application performance management (APM) service provided by Azure which integrates very well with App Service. In fact, you can enable Application Insights for your App Service Application without the need to make any code changes.

This post is going to cover using an existing App Service application and enabling Application Insights. This post is assuming that you already have an Azure account. If you don’t you can sign up for a free Azure account.

Sample Application and App Service Creation

In case you don’t have an existing application in Azure App Service here is a quick walkthrough of the application I used for this post. If you have an existing application you can skip to the next section.

From the .NET CLI I used the following command to create a global.json targeting .NET Core 2.2 in the directory the application is being created in. You don’t have to do this step, but I needed it because I have .NET Core 3 preview installed and I wanted this post to target the current production release of .NET Core.

dotnet new globaljson --sdk-version 2.2.105

Next, run the following command to create a new ASP.NET Core application using the React template. Any of the templates are fine so feel free to use a different one as long as it will give you a web application.

dotnet new react

Now open the new project in Visual Studio and right-click on the project file and click Publish.

Select App Service and then click Publish.

The next dialog is all about the setup of your App Service. I took the defaults for the most part, with the exception of the Resource Group which I made sure to create one just for this application to allow for easy clean up later. When you have all your options selected click Create. Note that there is an option to setup Application Insights from this screen, but we are going to handle this on the Azure side after the fact for this post.

After the deployment is done your application should open up in a browser.

Add Application Insights from the Azure Portal

Now that we have an application running in an Azure App Service we are ready to add in Application Insights. First head to the Azure Portal and select App Services from the menu.

From your list of App Services select the one you want to add Application Insights to. From the menu select Application Insights. In the details click the Turn on site extension button to update the Application Insights extension if needed.

On the next screen select the Location where you would like the Application Insights deployed. You can tweak what will be instrumented based on the language your application is built in, I just kept the defaults. When all your selections are done click Apply.

When you click apply, you will get a warning that your site will have to be restarted. For a test application, this isn’t a big deal, but if you are on a production application you might want to do this during a slow period. Click Yes to continue.

After the process is complete click the View Application Insights data link to view your Application Insights Overview.

The overview will give you a fast overview of how your application is doing with graphs of Failed request, Server response time, Server requests, and Availability.

Wrapping Up

Hopefully, this will help you get going with Application Insights. This post didn’t cover many of the features that Application Insights provides, but should get you set up so you can explore all the features the service provides.

Deploy ASP.NET Core 3 Previews to Azure App Service

I have found some time to play around with some of the features coming with ASP.NET Core 3 and I needed a place to host some of the applications I’m playing around with. Azure App Services has always been a great place for this type of thing, but as you will see in the details below it doesn’t support ASP.NET Core 3 by default currently.

This post is going to walk through creating a new ASP.NET Core 3 React application and publishing it to a new App Service with the default setting and then show you what to change to get the application to run.

Sample Application

I used the following .NET CLI command to create a new ASP.NET Core application using React for its front end.

dotnet new react

After the creation process is complete open the project in Visual Studio. I highly recommend using the Visual Studio 2019 preview release when working with any .NET Core 3 applications.

Publish to App Service

In Visual Studio’s Solution Explorer right click on the project file and select Publish.

Select App Service for the publish target. Here we are creating a new app service. Next, click Publish.

The next dialog if the information about the new App Service that will be created. I took the defaults for the most part. I did create a new resource group for this application to make the resources easier to clean up in the future. I also changed the hosting plan to the free tier. Click Create to continue.

The Error and the Warning

As part of the publishing process, a browser will be opened to the address of the application. When this happens you will see an error about ANCM In-Process Handler Load Failure (if you are using IIS In-Process Hosting).

If you look back at Visual Studio you will see the following warning that your application requires the .NET Core runtime 3.0 and App Service only supports up to 2.2.

The Fix

After dismissing the dialog above you will see a summary of the publish profile we created above. Click the Pincel next to the Framework-Dependent value for Deployment Mode.

In the dialog that pops up set the Deployment Mode to Self-Contained and select an appropriate Target Runtime for your App Service. In the case of this sample which is deployed to a Windows App Service, we are using win-x86.

Back on the publish profile summary screen click the Publish button to redeploy the application to App Service with the new settings. When the process finishes this time you should see a browser load with your application running properly.

Wrapping Up

This is a great example of the power of being able to do self-contained deployments. If this option didn’t exist then we would have no option for running .NET Core 3 applications on App Service.