ASP.NET Core

Environment Variables are one of the sources from which ASP.NET Core reads the configuration values. In this tutorial, let us learn how to set Environment Variables in Windows, Mac, Linux, IIS Server, Visual Studio, Visual Studio Code & dotnet run. We also learn how to read them in ASP.NET core.

appsettings.json is one of the several ways, in which we can provide the configuration values to ASP.NET core application. You will find this file in the root folder of our project. We can also create environment-specific files like appsettings.development.json, appsettngs.production.json, etc. The ASP.NET Core configuration system loads the appsettings.json and also the environment-specific file based on the current environment.

The launchSettings.json file is used to store the configuration information, which describes how to start the ASP.NET Core application, using Visual Studio. The file is used only during the development of the application using Visual Studio. It contains only those settings that required to run the application. This file is ignored when we publish the app.

ASPNETCORE_ENVIRONMENT is an environment variable, which ASP.NET Core uses to identify the runtime environment. ASP.NET Core configuration system uses it to load different configurations for different stages of application like Development, Staging & Production, etc. In this tutorial, we will show what is ASPNETCORE_ENVIRONMENT and how to set its value while developing the application and while hosting the application, etc

In this article, we will find the role of the startup class in ASP.NET Core. We learned how the Program class is responsible for creating a Web Host and configuring it. But, before building and running the host, the program class checks for startup class for further configuration. It invokes the Configure & ConfigureServices the method from the class. This allows us to further configure the App startup.