Contents tagged with ASP.NET Core

  • Breaking Changes in coming your way for ASP.NET Core 3.0

    Microsoft is in the process of releasing a new version for their .NET Core framework and there are some significant changes coming your way in that release. The most important ones are

    1. Removal of some sub-components
    2. Removal of the PackageReference to Microsoft.AspNetCore.App
    3. Reducing duplication between NuGet packages and shared frameworks

    In v3.0, the ASP.NET Core framework will contain only those assemblies which are fully developed, supported and serviceable by Microsoft. They are doing this to reap all the benefits provided by the .NET Core shared frameworks like smaller deployment size, faster bootup time, centralized patching etc

    Removal of some sub-components

    In this version, they are removing some sub-components from the ASP.NET Core shared framework and most notable among them are the following


    JSON format has become so popular these days and has become the primary method for transferring data in all modern applications. But .NET doesn't have a built-in library to deal with JSON and relied on third-party libraries like JSON.NET for some time now. In ASP.NET Core, it has a tight integration with Json.NET which restricted the users to chose another library or a different version of Json.NET itself. 

    So with version 3.0 they have decoupled Json.NET from the ASP.NET Core shared framework and is planning to replace it with high-performance JSON APIs. That means you will now need to add Json.NET as a separate package in you ASP.NET Core 3.0 project

    and then update your ConfigureServices method to include a call to AddNewtonsoftJson() as shown below

    public void ConfigureServices(IServiceCollection services)

  • Spin up Docker Containers in a Kubernetes Cluster hosted in Azure Container Service

    In one of the earlier posts, I have explained in details about the steps that need to be performed for running Docker containers in a Kubernetes cluster hosted in Azure. In that example, I used the default IIS image from Docker Hub for spinning up a new container in the cluster. In this post, I will show you how to containerize an ASP.NET Core MVC application using a private Docker registry and spin-off containers in a cluster hosted in Azure using Azure Container Service


    1. Azure Subscription
    2. Azure CLI
    3. kubectl 

    You need to install both the CLI tools for Azure and Kubernetes in your local machine for these commands to work and needs an Azure subscription for deploying the cluster in Azure Container Service.

    Step 1: Create a Kubernetes Cluster using Azure Container Service

    The first step is to create the create the cluster in Azure, for that we will use the az acs create command available in Azure CLI. You need to provide a resource group and a name for the cluster. A resource group in Azure is like a virtual container that holds a collection of assets for easy monitoring, access control etc. The --generate-ssh-keys parameter will tell the command to create the public and private key files which can be used for connecting to the cluster.

    az acs create --orchestrator-type kubernetes --resource-group TrainingInstanceRG1 --name TrainingCluster1 --generate-ssh-keys

    Step 2: Get the credentials for the Kubernetes Cluster

    Now we need to download the credentials to our local machine for accessing the cluster. 

    az acs kubernetes get-credentials --name TrainingCluster1 --resource-group TrainingInstanceRG1

    When the command is executed it will download the key files to your local machine and by default, it will reside in a folder under user folder. 

  • Implementing Functional Testing in MVC Application using ASP.NET Core 2.1.0-preview1

    Functional Testing plays an important role in delivering software products with great quality and reliability. Even though the ability to write in-memory functional tests in ASP. NET Core MVC application is present in ASP.NET Core 2.0, it had some pitfalls

    1. Manual copying of the .deps files from application project into the bin folder of the test project
    2. Needed to manually set the content root of the application project so that static files and views can be found
    3. Bootstrapping  the app on the Test Server.

    In ASP.NET Core 2.1, Microsoft has released a new package Microsoft.AspNetCore.Mvc.Testing which solves all the above mentioned problems and helps you to write and execute in-memory functional tests more efficiently. To check how it can be done, let's create two projects - one for the web application and another for our test project.

    Step 1

    Create an ASP.NET Core MVC project without any authentication. The following command will create one in the folder specified by the -o switch

    dotnet new mvc -au none -o SampleWeb/src/WebApp

    Step 2

    Let's add a test project based on Xunit test framework using the below command. As in Step 1, the project will be created in the specified folder

    dotnet new xunit -o SampleWeb/test/WebApp.Tests

    Step 3

    Now we will create a solution file and add these two projects into it. 

    cd SampleWeb

    dotnet new sln

    dotnet sln add src/WebApp/WebApp.csproj

    dotnet sln add .\test\WebApp.Tests\WebApp.Tests.csproj

  • Hosting a ASP.NET Core application in a Docker container using microsoft/aspnetcore image

    You all will be familiar with Docker by now given its popularity among developers and infra people and some of you may have already created containers using Docker images. One of the most widely used workflows among people using .NET Core will create a new web application by using the dotnet new command as shown below.

    The below example uses ASP.NET Core 2.0 framework, in which the dotnet new command will create the project as well as restores the dependencies specified in the csproj file by default. I have already written a post about it and you can refer it for information about it

    Then you will do a build to see if there are any errors and use dotnet run command which will self-host the web application